diff --git a/2025-03/spring-38-kafka/.gitignore b/2025-03/spring-38-kafka/.gitignore
new file mode 100644
index 00000000..dae2cf99
--- /dev/null
+++ b/2025-03/spring-38-kafka/.gitignore
@@ -0,0 +1,39 @@
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# BlueJ files
+*.ctxt
+
+# Mobile Tools for Java (J2ME)
+.mtj.tmp/
+
+# Package Files #
+*.jar
+!gradle-wrapper.jar
+*.war
+*.nar
+*.ear
+*.zip
+*.tar.gz
+*.rar
+
+# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
+hs_err_pid*
+
+# Ignore Gradle project-specific cache directory
+.gradle
+/buildSrc/.gradle/
+
+# Ignore Gradle build output directory
+build
+out
+
+#Idea
+*.iml
+*.iws
+*.ipr
+*.idea
+
diff --git a/2025-03/spring-38-kafka/.mvn/wrapper/MavenWrapperDownloader.java b/2025-03/spring-38-kafka/.mvn/wrapper/MavenWrapperDownloader.java
new file mode 100644
index 00000000..e76d1f32
--- /dev/null
+++ b/2025-03/spring-38-kafka/.mvn/wrapper/MavenWrapperDownloader.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+ private static final String WRAPPER_VERSION = "0.5.6";
+ /**
+ * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+ */
+ private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+ + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+ /**
+ * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+ * use instead of the default one.
+ */
+ private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+ ".mvn/wrapper/maven-wrapper.properties";
+
+ /**
+ * Path where the maven-wrapper.jar will be saved to.
+ */
+ private static final String MAVEN_WRAPPER_JAR_PATH =
+ ".mvn/wrapper/maven-wrapper.jar";
+
+ /**
+ * Name of the property which should be used to override the default download url for the wrapper.
+ */
+ private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+ public static void main(String args[]) {
+ System.out.println("- Downloader started");
+ File baseDirectory = new File(args[0]);
+ System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+ // If the maven-wrapper.properties exists, read it and check if it contains a custom
+ // wrapperUrl parameter.
+ File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+ String url = DEFAULT_DOWNLOAD_URL;
+ if(mavenWrapperPropertyFile.exists()) {
+ FileInputStream mavenWrapperPropertyFileInputStream = null;
+ try {
+ mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+ Properties mavenWrapperProperties = new Properties();
+ mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+ url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+ } catch (IOException e) {
+ System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+ } finally {
+ try {
+ if(mavenWrapperPropertyFileInputStream != null) {
+ mavenWrapperPropertyFileInputStream.close();
+ }
+ } catch (IOException e) {
+ // Ignore ...
+ }
+ }
+ }
+ System.out.println("- Downloading from: " + url);
+
+ File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+ if(!outputFile.getParentFile().exists()) {
+ if(!outputFile.getParentFile().mkdirs()) {
+ System.out.println(
+ "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+ }
+ }
+ System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+ try {
+ downloadFileFromURL(url, outputFile);
+ System.out.println("Done");
+ System.exit(0);
+ } catch (Throwable e) {
+ System.out.println("- Error downloading");
+ e.printStackTrace();
+ System.exit(1);
+ }
+ }
+
+ private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+ if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+ String username = System.getenv("MVNW_USERNAME");
+ char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+ Authenticator.setDefault(new Authenticator() {
+ @Override
+ protected PasswordAuthentication getPasswordAuthentication() {
+ return new PasswordAuthentication(username, password);
+ }
+ });
+ }
+ URL website = new URL(urlString);
+ ReadableByteChannel rbc;
+ rbc = Channels.newChannel(website.openStream());
+ FileOutputStream fos = new FileOutputStream(destination);
+ fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+ fos.close();
+ rbc.close();
+ }
+
+}
diff --git a/2025-03/spring-38-kafka/.mvn/wrapper/maven-wrapper.properties b/2025-03/spring-38-kafka/.mvn/wrapper/maven-wrapper.properties
new file mode 100644
index 00000000..642d572c
--- /dev/null
+++ b/2025-03/spring-38-kafka/.mvn/wrapper/maven-wrapper.properties
@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar
diff --git a/2025-03/spring-38-kafka/consumer/.mvn/wrapper/MavenWrapperDownloader.java b/2025-03/spring-38-kafka/consumer/.mvn/wrapper/MavenWrapperDownloader.java
new file mode 100644
index 00000000..e76d1f32
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/.mvn/wrapper/MavenWrapperDownloader.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+ private static final String WRAPPER_VERSION = "0.5.6";
+ /**
+ * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+ */
+ private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+ + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+ /**
+ * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+ * use instead of the default one.
+ */
+ private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+ ".mvn/wrapper/maven-wrapper.properties";
+
+ /**
+ * Path where the maven-wrapper.jar will be saved to.
+ */
+ private static final String MAVEN_WRAPPER_JAR_PATH =
+ ".mvn/wrapper/maven-wrapper.jar";
+
+ /**
+ * Name of the property which should be used to override the default download url for the wrapper.
+ */
+ private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+ public static void main(String args[]) {
+ System.out.println("- Downloader started");
+ File baseDirectory = new File(args[0]);
+ System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+ // If the maven-wrapper.properties exists, read it and check if it contains a custom
+ // wrapperUrl parameter.
+ File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+ String url = DEFAULT_DOWNLOAD_URL;
+ if(mavenWrapperPropertyFile.exists()) {
+ FileInputStream mavenWrapperPropertyFileInputStream = null;
+ try {
+ mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+ Properties mavenWrapperProperties = new Properties();
+ mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+ url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+ } catch (IOException e) {
+ System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+ } finally {
+ try {
+ if(mavenWrapperPropertyFileInputStream != null) {
+ mavenWrapperPropertyFileInputStream.close();
+ }
+ } catch (IOException e) {
+ // Ignore ...
+ }
+ }
+ }
+ System.out.println("- Downloading from: " + url);
+
+ File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+ if(!outputFile.getParentFile().exists()) {
+ if(!outputFile.getParentFile().mkdirs()) {
+ System.out.println(
+ "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+ }
+ }
+ System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+ try {
+ downloadFileFromURL(url, outputFile);
+ System.out.println("Done");
+ System.exit(0);
+ } catch (Throwable e) {
+ System.out.println("- Error downloading");
+ e.printStackTrace();
+ System.exit(1);
+ }
+ }
+
+ private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+ if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+ String username = System.getenv("MVNW_USERNAME");
+ char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+ Authenticator.setDefault(new Authenticator() {
+ @Override
+ protected PasswordAuthentication getPasswordAuthentication() {
+ return new PasswordAuthentication(username, password);
+ }
+ });
+ }
+ URL website = new URL(urlString);
+ ReadableByteChannel rbc;
+ rbc = Channels.newChannel(website.openStream());
+ FileOutputStream fos = new FileOutputStream(destination);
+ fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+ fos.close();
+ rbc.close();
+ }
+
+}
diff --git a/2025-03/spring-38-kafka/consumer/.mvn/wrapper/maven-wrapper.properties b/2025-03/spring-38-kafka/consumer/.mvn/wrapper/maven-wrapper.properties
new file mode 100644
index 00000000..642d572c
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/.mvn/wrapper/maven-wrapper.properties
@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar
diff --git a/2025-03/spring-38-kafka/consumer/mvnw b/2025-03/spring-38-kafka/consumer/mvnw
new file mode 100755
index 00000000..a16b5431
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/mvnw
@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+# JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+# M2_HOME - location of maven2's installed home dir
+# MAVEN_OPTS - parameters passed to the Java VM when running Maven
+# e.g. to debug Maven itself, use
+# set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+# MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+ if [ -f /etc/mavenrc ] ; then
+ . /etc/mavenrc
+ fi
+
+ if [ -f "$HOME/.mavenrc" ] ; then
+ . "$HOME/.mavenrc"
+ fi
+
+fi
+
+# OS specific support. $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+ CYGWIN*) cygwin=true ;;
+ MINGW*) mingw=true;;
+ Darwin*) darwin=true
+ # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+ # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+ if [ -z "$JAVA_HOME" ]; then
+ if [ -x "/usr/libexec/java_home" ]; then
+ export JAVA_HOME="`/usr/libexec/java_home`"
+ else
+ export JAVA_HOME="/Library/Java/Home"
+ fi
+ fi
+ ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+ if [ -r /etc/gentoo-release ] ; then
+ JAVA_HOME=`java-config --jre-home`
+ fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+ ## resolve links - $0 may be a link to maven's home
+ PRG="$0"
+
+ # need this for relative symlinks
+ while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG="`dirname "$PRG"`/$link"
+ fi
+ done
+
+ saveddir=`pwd`
+
+ M2_HOME=`dirname "$PRG"`/..
+
+ # make it fully qualified
+ M2_HOME=`cd "$M2_HOME" && pwd`
+
+ cd "$saveddir"
+ # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --unix "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME="`(cd "$M2_HOME"; pwd)`"
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+ javaExecutable="`which javac`"
+ if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+ # readlink(1) is not available as standard on Solaris 10.
+ readLink=`which readlink`
+ if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+ if $darwin ; then
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+ else
+ javaExecutable="`readlink -f \"$javaExecutable\"`"
+ fi
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+ JAVA_HOME="$javaHome"
+ export JAVA_HOME
+ fi
+ fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+ if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ else
+ JAVACMD="`which java`"
+ fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+ echo "Error: JAVA_HOME is not defined correctly." >&2
+ echo " We cannot execute $JAVACMD" >&2
+ exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+ echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+ if [ -z "$1" ]
+ then
+ echo "Path not specified to find_maven_basedir"
+ return 1
+ fi
+
+ basedir="$1"
+ wdir="$1"
+ while [ "$wdir" != '/' ] ; do
+ if [ -d "$wdir"/.mvn ] ; then
+ basedir=$wdir
+ break
+ fi
+ # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+ if [ -d "${wdir}" ]; then
+ wdir=`cd "$wdir/.."; pwd`
+ fi
+ # end of workaround
+ done
+ echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+ if [ -f "$1" ]; then
+ echo "$(tr -s '\n' ' ' < "$1")"
+ fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+ exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found .mvn/wrapper/maven-wrapper.jar"
+ fi
+else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+ fi
+ if [ -n "$MVNW_REPOURL" ]; then
+ jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ else
+ jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ fi
+ while IFS="=" read key value; do
+ case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+ esac
+ done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Downloading from: $jarUrl"
+ fi
+ wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+ if $cygwin; then
+ wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+ fi
+
+ if command -v wget > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found wget ... using wget"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ wget "$jarUrl" -O "$wrapperJarPath"
+ else
+ wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+ fi
+ elif command -v curl > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found curl ... using curl"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ curl -o "$wrapperJarPath" "$jarUrl" -f
+ else
+ curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+ fi
+
+ else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Falling back to using Java to download"
+ fi
+ javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+ # For Cygwin, switch paths to Windows format before running javac
+ if $cygwin; then
+ javaClass=`cygpath --path --windows "$javaClass"`
+ fi
+ if [ -e "$javaClass" ]; then
+ if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Compiling MavenWrapperDownloader.java ..."
+ fi
+ # Compiling the Java class
+ ("$JAVA_HOME/bin/javac" "$javaClass")
+ fi
+ if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ # Running the downloader
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Running MavenWrapperDownloader.java ..."
+ fi
+ ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+ fi
+ fi
+ fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+ echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --path --windows "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+ [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+ MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+ $MAVEN_OPTS \
+ -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+ "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+ ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"
diff --git a/2025-03/spring-38-kafka/consumer/mvnw.cmd b/2025-03/spring-38-kafka/consumer/mvnw.cmd
new file mode 100644
index 00000000..c8d43372
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/mvnw.cmd
@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements. See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership. The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License. You may obtain a copy of the License at
+@REM
+@REM https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied. See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+ IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Found %WRAPPER_JAR%
+ )
+) else (
+ if not "%MVNW_REPOURL%" == "" (
+ SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ )
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Couldn't find %WRAPPER_JAR%, downloading it ...
+ echo Downloading from: %DOWNLOAD_URL%
+ )
+
+ powershell -Command "&{"^
+ "$webclient = new-object System.Net.WebClient;"^
+ "if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+ "$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+ "}"^
+ "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+ "}"
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Finished downloading %WRAPPER_JAR%
+ )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%
diff --git a/2025-03/spring-38-kafka/consumer/pom.xml b/2025-03/spring-38-kafka/consumer/pom.xml
new file mode 100644
index 00000000..f270f281
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/pom.xml
@@ -0,0 +1,49 @@
+
+
+ 4.0.0
+
+
+ ru.otus
+ spring-38-kafka
+ 1.0
+
+
+ consumer
+ 1.0
+
+
+ 21
+
+
+
+
+ org.springframework.boot
+ spring-boot-starter
+
+
+
+ org.springframework.kafka
+ spring-kafka
+
+
+
+ com.fasterxml.jackson.core
+ jackson-databind
+
+
+ com.google.code.findbugs
+ jsr305
+
+
+
+
+
+
+ org.springframework.boot
+ spring-boot-maven-plugin
+
+
+
+
diff --git a/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/ConsumerApp.java b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/ConsumerApp.java
new file mode 100644
index 00000000..a9e6aa58
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/ConsumerApp.java
@@ -0,0 +1,11 @@
+package ru.demo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ConsumerApp {
+ public static void main(String[] args) {
+ SpringApplication.run(ConsumerApp.class, args);
+ }
+}
diff --git a/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/config/ApplicationConfig.java b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/config/ApplicationConfig.java
new file mode 100644
index 00000000..dc63a5a8
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/config/ApplicationConfig.java
@@ -0,0 +1,108 @@
+package ru.demo.config;
+
+import static org.springframework.kafka.support.serializer.JsonDeserializer.TYPE_MAPPINGS;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import java.util.List;
+import org.apache.kafka.clients.admin.NewTopic;
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.common.serialization.StringDeserializer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.task.SimpleAsyncTaskExecutor;
+import org.springframework.kafka.annotation.KafkaListener;
+import org.springframework.kafka.config.ConcurrentKafkaListenerContainerFactory;
+import org.springframework.kafka.config.KafkaListenerContainerFactory;
+import org.springframework.kafka.config.TopicBuilder;
+import org.springframework.kafka.core.ConsumerFactory;
+import org.springframework.kafka.core.DefaultKafkaConsumerFactory;
+import org.springframework.kafka.listener.ConcurrentMessageListenerContainer;
+import org.springframework.kafka.support.JacksonUtils;
+import org.springframework.kafka.support.serializer.JsonDeserializer;
+import org.springframework.messaging.handler.annotation.Payload;
+import org.springframework.scheduling.concurrent.ConcurrentTaskExecutor;
+import ru.demo.model.StringValue;
+import ru.demo.service.StringValueConsumer;
+import ru.demo.service.StringValueConsumerLogger;
+
+@Configuration
+public class ApplicationConfig {
+ private static final Logger log = LoggerFactory.getLogger(ApplicationConfig.class);
+ public final String topicName;
+
+ public ApplicationConfig(@Value("${application.kafka.topic}") String topicName) {
+ this.topicName = topicName;
+ }
+
+ @Bean
+ public ObjectMapper objectMapper() {
+ return JacksonUtils.enhancedObjectMapper();
+ }
+
+ @Bean
+ public ConsumerFactory consumerFactory(
+ KafkaProperties kafkaProperties, ObjectMapper mapper) {
+ var props = kafkaProperties.buildConsumerProperties();
+ props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
+ props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
+ props.put(TYPE_MAPPINGS, "ru.demo.model.StringValue:ru.demo.model.StringValue");
+ props.put(ConsumerConfig.MAX_POLL_RECORDS_CONFIG, 3);
+ props.put(ConsumerConfig.MAX_POLL_INTERVAL_MS_CONFIG, 3_000);
+
+ var kafkaConsumerFactory = new DefaultKafkaConsumerFactory(props);
+ kafkaConsumerFactory.setValueDeserializer(new JsonDeserializer<>(mapper));
+ return kafkaConsumerFactory;
+ }
+
+ @Bean("listenerContainerFactory")
+ public KafkaListenerContainerFactory>
+ listenerContainerFactory(ConsumerFactory consumerFactory) {
+ var factory = new ConcurrentKafkaListenerContainerFactory();
+ factory.setConsumerFactory(consumerFactory);
+ factory.setBatchListener(true);
+ factory.setConcurrency(1);
+ factory.getContainerProperties().setIdleBetweenPolls(1_000);
+ factory.getContainerProperties().setPollTimeout(1_000);
+
+ var executor = new SimpleAsyncTaskExecutor("k-consumer-");
+ executor.setConcurrencyLimit(10);
+ var listenerTaskExecutor = new ConcurrentTaskExecutor(executor);
+ factory.getContainerProperties().setListenerTaskExecutor(listenerTaskExecutor);
+ return factory;
+ }
+
+ @Bean
+ public NewTopic topic() {
+ return TopicBuilder.name(topicName).partitions(1).replicas(1).build();
+ }
+
+ @Bean
+ public StringValueConsumer stringValueConsumerLogger() {
+ return new StringValueConsumerLogger();
+ }
+
+ @Bean
+ public KafkaClient stringValueConsumer(StringValueConsumer stringValueConsumer) {
+ return new KafkaClient(stringValueConsumer);
+ }
+
+ public static class KafkaClient {
+ private final StringValueConsumer stringValueConsumer;
+
+ public KafkaClient(StringValueConsumer stringValueConsumer) {
+ this.stringValueConsumer = stringValueConsumer;
+ }
+
+ @KafkaListener(
+ topics = "${application.kafka.topic}",
+ containerFactory = "listenerContainerFactory")
+ public void listen(@Payload List values) {
+ log.info("values, values.size:{}", values.size());
+ stringValueConsumer.accept(values);
+ }
+ }
+}
diff --git a/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/model/StringValue.java b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/model/StringValue.java
new file mode 100644
index 00000000..213f1309
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/model/StringValue.java
@@ -0,0 +1,3 @@
+package ru.demo.model;
+
+public record StringValue(long id, String value) {}
diff --git a/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumer.java b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumer.java
new file mode 100644
index 00000000..ff5cd296
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumer.java
@@ -0,0 +1,9 @@
+package ru.demo.service;
+
+import java.util.List;
+import ru.demo.model.StringValue;
+
+public interface StringValueConsumer {
+
+ void accept(List value);
+}
diff --git a/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumerLogger.java b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumerLogger.java
new file mode 100644
index 00000000..c791cbea
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/java/ru/demo/service/StringValueConsumerLogger.java
@@ -0,0 +1,17 @@
+package ru.demo.service;
+
+import java.util.List;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import ru.demo.model.StringValue;
+
+public class StringValueConsumerLogger implements StringValueConsumer {
+ private static final Logger log = LoggerFactory.getLogger(StringValueConsumerLogger.class);
+
+ @Override
+ public void accept(List values) {
+ for (var value : values) {
+ log.info("log:{}", value);
+ }
+ }
+}
diff --git a/2025-03/spring-38-kafka/consumer/src/main/resources/application.yml b/2025-03/spring-38-kafka/consumer/src/main/resources/application.yml
new file mode 100644
index 00000000..32db801b
--- /dev/null
+++ b/2025-03/spring-38-kafka/consumer/src/main/resources/application.yml
@@ -0,0 +1,12 @@
+application:
+ kafka:
+ topic: "demo-topic"
+
+
+spring:
+ kafka:
+ consumer:
+ group-id: "test-group"
+ bootstrap-servers: "localhost:9092"
+ client-id: "demo-consumer"
+ auto-offset-reset: earliest
diff --git a/2025-03/spring-38-kafka/docker/docker-compose.yml b/2025-03/spring-38-kafka/docker/docker-compose.yml
new file mode 100644
index 00000000..b16128f3
--- /dev/null
+++ b/2025-03/spring-38-kafka/docker/docker-compose.yml
@@ -0,0 +1,24 @@
+
+services:
+ zookeeper:
+ image: confluentinc/cp-zookeeper:6.2.0
+ container_name: zookeeper
+ environment:
+ ZOOKEEPER_CLIENT_PORT: 2181
+ ZOOKEEPER_TICK_TIME: 2000
+
+ broker:
+ image: confluentinc/cp-kafka:7.0.0
+ container_name: broker
+ ports:
+ - "9092:9092"
+ depends_on:
+ - zookeeper
+ environment:
+ KAFKA_BROKER_ID: 1
+ KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
+ KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_INTERNAL:PLAINTEXT
+ KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://localhost:9092,PLAINTEXT_INTERNAL://broker:29092
+ KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
+ KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
+ KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
\ No newline at end of file
diff --git a/2025-03/spring-38-kafka/mvnw b/2025-03/spring-38-kafka/mvnw
new file mode 100755
index 00000000..a16b5431
--- /dev/null
+++ b/2025-03/spring-38-kafka/mvnw
@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+# JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+# M2_HOME - location of maven2's installed home dir
+# MAVEN_OPTS - parameters passed to the Java VM when running Maven
+# e.g. to debug Maven itself, use
+# set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+# MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+ if [ -f /etc/mavenrc ] ; then
+ . /etc/mavenrc
+ fi
+
+ if [ -f "$HOME/.mavenrc" ] ; then
+ . "$HOME/.mavenrc"
+ fi
+
+fi
+
+# OS specific support. $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+ CYGWIN*) cygwin=true ;;
+ MINGW*) mingw=true;;
+ Darwin*) darwin=true
+ # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+ # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+ if [ -z "$JAVA_HOME" ]; then
+ if [ -x "/usr/libexec/java_home" ]; then
+ export JAVA_HOME="`/usr/libexec/java_home`"
+ else
+ export JAVA_HOME="/Library/Java/Home"
+ fi
+ fi
+ ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+ if [ -r /etc/gentoo-release ] ; then
+ JAVA_HOME=`java-config --jre-home`
+ fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+ ## resolve links - $0 may be a link to maven's home
+ PRG="$0"
+
+ # need this for relative symlinks
+ while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG="`dirname "$PRG"`/$link"
+ fi
+ done
+
+ saveddir=`pwd`
+
+ M2_HOME=`dirname "$PRG"`/..
+
+ # make it fully qualified
+ M2_HOME=`cd "$M2_HOME" && pwd`
+
+ cd "$saveddir"
+ # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --unix "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME="`(cd "$M2_HOME"; pwd)`"
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+ javaExecutable="`which javac`"
+ if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+ # readlink(1) is not available as standard on Solaris 10.
+ readLink=`which readlink`
+ if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+ if $darwin ; then
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+ else
+ javaExecutable="`readlink -f \"$javaExecutable\"`"
+ fi
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+ JAVA_HOME="$javaHome"
+ export JAVA_HOME
+ fi
+ fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+ if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ else
+ JAVACMD="`which java`"
+ fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+ echo "Error: JAVA_HOME is not defined correctly." >&2
+ echo " We cannot execute $JAVACMD" >&2
+ exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+ echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+ if [ -z "$1" ]
+ then
+ echo "Path not specified to find_maven_basedir"
+ return 1
+ fi
+
+ basedir="$1"
+ wdir="$1"
+ while [ "$wdir" != '/' ] ; do
+ if [ -d "$wdir"/.mvn ] ; then
+ basedir=$wdir
+ break
+ fi
+ # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+ if [ -d "${wdir}" ]; then
+ wdir=`cd "$wdir/.."; pwd`
+ fi
+ # end of workaround
+ done
+ echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+ if [ -f "$1" ]; then
+ echo "$(tr -s '\n' ' ' < "$1")"
+ fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+ exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found .mvn/wrapper/maven-wrapper.jar"
+ fi
+else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+ fi
+ if [ -n "$MVNW_REPOURL" ]; then
+ jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ else
+ jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ fi
+ while IFS="=" read key value; do
+ case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+ esac
+ done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Downloading from: $jarUrl"
+ fi
+ wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+ if $cygwin; then
+ wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+ fi
+
+ if command -v wget > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found wget ... using wget"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ wget "$jarUrl" -O "$wrapperJarPath"
+ else
+ wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+ fi
+ elif command -v curl > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found curl ... using curl"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ curl -o "$wrapperJarPath" "$jarUrl" -f
+ else
+ curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+ fi
+
+ else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Falling back to using Java to download"
+ fi
+ javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+ # For Cygwin, switch paths to Windows format before running javac
+ if $cygwin; then
+ javaClass=`cygpath --path --windows "$javaClass"`
+ fi
+ if [ -e "$javaClass" ]; then
+ if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Compiling MavenWrapperDownloader.java ..."
+ fi
+ # Compiling the Java class
+ ("$JAVA_HOME/bin/javac" "$javaClass")
+ fi
+ if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ # Running the downloader
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Running MavenWrapperDownloader.java ..."
+ fi
+ ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+ fi
+ fi
+ fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+ echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --path --windows "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+ [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+ MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+ $MAVEN_OPTS \
+ -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+ "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+ ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"
diff --git a/2025-03/spring-38-kafka/mvnw.cmd b/2025-03/spring-38-kafka/mvnw.cmd
new file mode 100644
index 00000000..c8d43372
--- /dev/null
+++ b/2025-03/spring-38-kafka/mvnw.cmd
@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements. See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership. The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License. You may obtain a copy of the License at
+@REM
+@REM https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied. See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+ IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Found %WRAPPER_JAR%
+ )
+) else (
+ if not "%MVNW_REPOURL%" == "" (
+ SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ )
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Couldn't find %WRAPPER_JAR%, downloading it ...
+ echo Downloading from: %DOWNLOAD_URL%
+ )
+
+ powershell -Command "&{"^
+ "$webclient = new-object System.Net.WebClient;"^
+ "if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+ "$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+ "}"^
+ "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+ "}"
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Finished downloading %WRAPPER_JAR%
+ )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%
diff --git a/2025-03/spring-38-kafka/pom.xml b/2025-03/spring-38-kafka/pom.xml
new file mode 100644
index 00000000..f761fa7a
--- /dev/null
+++ b/2025-03/spring-38-kafka/pom.xml
@@ -0,0 +1,92 @@
+
+
+ 4.0.0
+
+ ru.otus
+ spring-38-kafka
+ 1.0
+
+
+ org.springframework.boot
+ spring-boot-starter-parent
+ 3.4.5
+
+
+ pom
+
+
+ consumer
+ producer
+
+
+
+ UTF-8
+ 21
+ 21
+ 3.0.0-M3
+ 3.1.1
+ 3.3.9
+ 1.0.12.RELEASE
+ 3.4.5
+ 3.0.2
+
+
+
+
+
+ org.springframework.boot
+ spring-boot-dependencies
+ ${springframeworkBoot.version}
+ pom
+ import
+
+
+ com.google.code.findbugs
+ jsr305
+ ${jsr305.version}
+
+
+
+
+
+
+
+
+
+ maven-enforcer-plugin
+ ${maven-enforcer-plugin.version}
+
+
+ enforce-maven
+
+ enforce
+
+
+
+
+
+ ${minimal.maven.version}
+
+
+
+
+
+
+
+
+ org.apache.maven.plugins
+ maven-shade-plugin
+ ${maven-shade-plugin.version}
+
+
+
+ org.apache.maven.plugins
+ maven-assembly-plugin
+ ${maven-assembly-plugin.version}
+
+
+
+
+
diff --git a/2025-03/spring-38-kafka/producer/.mvn/wrapper/MavenWrapperDownloader.java b/2025-03/spring-38-kafka/producer/.mvn/wrapper/MavenWrapperDownloader.java
new file mode 100644
index 00000000..e76d1f32
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/.mvn/wrapper/MavenWrapperDownloader.java
@@ -0,0 +1,117 @@
+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+ private static final String WRAPPER_VERSION = "0.5.6";
+ /**
+ * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+ */
+ private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+ + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+ /**
+ * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+ * use instead of the default one.
+ */
+ private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+ ".mvn/wrapper/maven-wrapper.properties";
+
+ /**
+ * Path where the maven-wrapper.jar will be saved to.
+ */
+ private static final String MAVEN_WRAPPER_JAR_PATH =
+ ".mvn/wrapper/maven-wrapper.jar";
+
+ /**
+ * Name of the property which should be used to override the default download url for the wrapper.
+ */
+ private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+ public static void main(String args[]) {
+ System.out.println("- Downloader started");
+ File baseDirectory = new File(args[0]);
+ System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+ // If the maven-wrapper.properties exists, read it and check if it contains a custom
+ // wrapperUrl parameter.
+ File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+ String url = DEFAULT_DOWNLOAD_URL;
+ if(mavenWrapperPropertyFile.exists()) {
+ FileInputStream mavenWrapperPropertyFileInputStream = null;
+ try {
+ mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+ Properties mavenWrapperProperties = new Properties();
+ mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+ url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+ } catch (IOException e) {
+ System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+ } finally {
+ try {
+ if(mavenWrapperPropertyFileInputStream != null) {
+ mavenWrapperPropertyFileInputStream.close();
+ }
+ } catch (IOException e) {
+ // Ignore ...
+ }
+ }
+ }
+ System.out.println("- Downloading from: " + url);
+
+ File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+ if(!outputFile.getParentFile().exists()) {
+ if(!outputFile.getParentFile().mkdirs()) {
+ System.out.println(
+ "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+ }
+ }
+ System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+ try {
+ downloadFileFromURL(url, outputFile);
+ System.out.println("Done");
+ System.exit(0);
+ } catch (Throwable e) {
+ System.out.println("- Error downloading");
+ e.printStackTrace();
+ System.exit(1);
+ }
+ }
+
+ private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+ if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+ String username = System.getenv("MVNW_USERNAME");
+ char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+ Authenticator.setDefault(new Authenticator() {
+ @Override
+ protected PasswordAuthentication getPasswordAuthentication() {
+ return new PasswordAuthentication(username, password);
+ }
+ });
+ }
+ URL website = new URL(urlString);
+ ReadableByteChannel rbc;
+ rbc = Channels.newChannel(website.openStream());
+ FileOutputStream fos = new FileOutputStream(destination);
+ fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+ fos.close();
+ rbc.close();
+ }
+
+}
diff --git a/2025-03/spring-38-kafka/producer/.mvn/wrapper/maven-wrapper.properties b/2025-03/spring-38-kafka/producer/.mvn/wrapper/maven-wrapper.properties
new file mode 100644
index 00000000..642d572c
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/.mvn/wrapper/maven-wrapper.properties
@@ -0,0 +1,2 @@
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar
diff --git a/2025-03/spring-38-kafka/producer/mvnw b/2025-03/spring-38-kafka/producer/mvnw
new file mode 100755
index 00000000..a16b5431
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/mvnw
@@ -0,0 +1,310 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License. You may obtain a copy of the License at
+#
+# https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied. See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Maven Start Up Batch script
+#
+# Required ENV vars:
+# ------------------
+# JAVA_HOME - location of a JDK home dir
+#
+# Optional ENV vars
+# -----------------
+# M2_HOME - location of maven2's installed home dir
+# MAVEN_OPTS - parameters passed to the Java VM when running Maven
+# e.g. to debug Maven itself, use
+# set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+# MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+# ----------------------------------------------------------------------------
+
+if [ -z "$MAVEN_SKIP_RC" ] ; then
+
+ if [ -f /etc/mavenrc ] ; then
+ . /etc/mavenrc
+ fi
+
+ if [ -f "$HOME/.mavenrc" ] ; then
+ . "$HOME/.mavenrc"
+ fi
+
+fi
+
+# OS specific support. $var _must_ be set to either true or false.
+cygwin=false;
+darwin=false;
+mingw=false
+case "`uname`" in
+ CYGWIN*) cygwin=true ;;
+ MINGW*) mingw=true;;
+ Darwin*) darwin=true
+ # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home
+ # See https://developer.apple.com/library/mac/qa/qa1170/_index.html
+ if [ -z "$JAVA_HOME" ]; then
+ if [ -x "/usr/libexec/java_home" ]; then
+ export JAVA_HOME="`/usr/libexec/java_home`"
+ else
+ export JAVA_HOME="/Library/Java/Home"
+ fi
+ fi
+ ;;
+esac
+
+if [ -z "$JAVA_HOME" ] ; then
+ if [ -r /etc/gentoo-release ] ; then
+ JAVA_HOME=`java-config --jre-home`
+ fi
+fi
+
+if [ -z "$M2_HOME" ] ; then
+ ## resolve links - $0 may be a link to maven's home
+ PRG="$0"
+
+ # need this for relative symlinks
+ while [ -h "$PRG" ] ; do
+ ls=`ls -ld "$PRG"`
+ link=`expr "$ls" : '.*-> \(.*\)$'`
+ if expr "$link" : '/.*' > /dev/null; then
+ PRG="$link"
+ else
+ PRG="`dirname "$PRG"`/$link"
+ fi
+ done
+
+ saveddir=`pwd`
+
+ M2_HOME=`dirname "$PRG"`/..
+
+ # make it fully qualified
+ M2_HOME=`cd "$M2_HOME" && pwd`
+
+ cd "$saveddir"
+ # echo Using m2 at $M2_HOME
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched
+if $cygwin ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --unix "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --unix "$CLASSPATH"`
+fi
+
+# For Mingw, ensure paths are in UNIX format before anything is touched
+if $mingw ; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME="`(cd "$M2_HOME"; pwd)`"
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`"
+fi
+
+if [ -z "$JAVA_HOME" ]; then
+ javaExecutable="`which javac`"
+ if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then
+ # readlink(1) is not available as standard on Solaris 10.
+ readLink=`which readlink`
+ if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then
+ if $darwin ; then
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaExecutable="`cd \"$javaHome\" && pwd -P`/javac"
+ else
+ javaExecutable="`readlink -f \"$javaExecutable\"`"
+ fi
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+ JAVA_HOME="$javaHome"
+ export JAVA_HOME
+ fi
+ fi
+fi
+
+if [ -z "$JAVACMD" ] ; then
+ if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ else
+ JAVACMD="`which java`"
+ fi
+fi
+
+if [ ! -x "$JAVACMD" ] ; then
+ echo "Error: JAVA_HOME is not defined correctly." >&2
+ echo " We cannot execute $JAVACMD" >&2
+ exit 1
+fi
+
+if [ -z "$JAVA_HOME" ] ; then
+ echo "Warning: JAVA_HOME environment variable is not set."
+fi
+
+CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
+
+# traverses directory structure from process work directory to filesystem root
+# first directory with .mvn subdirectory is considered project base directory
+find_maven_basedir() {
+
+ if [ -z "$1" ]
+ then
+ echo "Path not specified to find_maven_basedir"
+ return 1
+ fi
+
+ basedir="$1"
+ wdir="$1"
+ while [ "$wdir" != '/' ] ; do
+ if [ -d "$wdir"/.mvn ] ; then
+ basedir=$wdir
+ break
+ fi
+ # workaround for JBEAP-8937 (on Solaris 10/Sparc)
+ if [ -d "${wdir}" ]; then
+ wdir=`cd "$wdir/.."; pwd`
+ fi
+ # end of workaround
+ done
+ echo "${basedir}"
+}
+
+# concatenates all lines of a file
+concat_lines() {
+ if [ -f "$1" ]; then
+ echo "$(tr -s '\n' ' ' < "$1")"
+ fi
+}
+
+BASE_DIR=`find_maven_basedir "$(pwd)"`
+if [ -z "$BASE_DIR" ]; then
+ exit 1;
+fi
+
+##########################################################################################
+# Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+# This allows using the maven wrapper in projects that prohibit checking in binary data.
+##########################################################################################
+if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found .mvn/wrapper/maven-wrapper.jar"
+ fi
+else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..."
+ fi
+ if [ -n "$MVNW_REPOURL" ]; then
+ jarUrl="$MVNW_REPOURL/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ else
+ jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ fi
+ while IFS="=" read key value; do
+ case "$key" in (wrapperUrl) jarUrl="$value"; break ;;
+ esac
+ done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties"
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Downloading from: $jarUrl"
+ fi
+ wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar"
+ if $cygwin; then
+ wrapperJarPath=`cygpath --path --windows "$wrapperJarPath"`
+ fi
+
+ if command -v wget > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found wget ... using wget"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ wget "$jarUrl" -O "$wrapperJarPath"
+ else
+ wget --http-user=$MVNW_USERNAME --http-password=$MVNW_PASSWORD "$jarUrl" -O "$wrapperJarPath"
+ fi
+ elif command -v curl > /dev/null; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Found curl ... using curl"
+ fi
+ if [ -z "$MVNW_USERNAME" ] || [ -z "$MVNW_PASSWORD" ]; then
+ curl -o "$wrapperJarPath" "$jarUrl" -f
+ else
+ curl --user $MVNW_USERNAME:$MVNW_PASSWORD -o "$wrapperJarPath" "$jarUrl" -f
+ fi
+
+ else
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo "Falling back to using Java to download"
+ fi
+ javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java"
+ # For Cygwin, switch paths to Windows format before running javac
+ if $cygwin; then
+ javaClass=`cygpath --path --windows "$javaClass"`
+ fi
+ if [ -e "$javaClass" ]; then
+ if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Compiling MavenWrapperDownloader.java ..."
+ fi
+ # Compiling the Java class
+ ("$JAVA_HOME/bin/javac" "$javaClass")
+ fi
+ if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then
+ # Running the downloader
+ if [ "$MVNW_VERBOSE" = true ]; then
+ echo " - Running MavenWrapperDownloader.java ..."
+ fi
+ ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR")
+ fi
+ fi
+ fi
+fi
+##########################################################################################
+# End of extension
+##########################################################################################
+
+export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"}
+if [ "$MVNW_VERBOSE" = true ]; then
+ echo $MAVEN_PROJECTBASEDIR
+fi
+MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin; then
+ [ -n "$M2_HOME" ] &&
+ M2_HOME=`cygpath --path --windows "$M2_HOME"`
+ [ -n "$JAVA_HOME" ] &&
+ JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"`
+ [ -n "$CLASSPATH" ] &&
+ CLASSPATH=`cygpath --path --windows "$CLASSPATH"`
+ [ -n "$MAVEN_PROJECTBASEDIR" ] &&
+ MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"`
+fi
+
+# Provide a "standardized" way to retrieve the CLI args that will
+# work with both Windows and non-Windows executions.
+MAVEN_CMD_LINE_ARGS="$MAVEN_CONFIG $@"
+export MAVEN_CMD_LINE_ARGS
+
+WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+exec "$JAVACMD" \
+ $MAVEN_OPTS \
+ -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \
+ "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \
+ ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@"
diff --git a/2025-03/spring-38-kafka/producer/mvnw.cmd b/2025-03/spring-38-kafka/producer/mvnw.cmd
new file mode 100644
index 00000000..c8d43372
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/mvnw.cmd
@@ -0,0 +1,182 @@
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements. See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership. The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License. You may obtain a copy of the License at
+@REM
+@REM https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied. See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+ IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Found %WRAPPER_JAR%
+ )
+) else (
+ if not "%MVNW_REPOURL%" == "" (
+ SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+ )
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Couldn't find %WRAPPER_JAR%, downloading it ...
+ echo Downloading from: %DOWNLOAD_URL%
+ )
+
+ powershell -Command "&{"^
+ "$webclient = new-object System.Net.WebClient;"^
+ "if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+ "$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+ "}"^
+ "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+ "}"
+ if "%MVNW_VERBOSE%" == "true" (
+ echo Finished downloading %WRAPPER_JAR%
+ )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%
diff --git a/2025-03/spring-38-kafka/producer/pom.xml b/2025-03/spring-38-kafka/producer/pom.xml
new file mode 100644
index 00000000..c3598163
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/pom.xml
@@ -0,0 +1,45 @@
+
+
+ 4.0.0
+
+
+ ru.otus
+ spring-38-kafka
+ 1.0
+
+
+ producer
+ 1.0
+
+
+ 21
+
+
+
+
+ org.springframework.boot
+ spring-boot-starter
+
+
+
+ org.springframework.kafka
+ spring-kafka
+
+
+
+ com.fasterxml.jackson.core
+ jackson-databind
+
+
+
+
+
+
+ org.springframework.boot
+ spring-boot-maven-plugin
+
+
+
+
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/ProducerApp.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/ProducerApp.java
new file mode 100644
index 00000000..e9d022bb
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/ProducerApp.java
@@ -0,0 +1,11 @@
+package ru.demo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ProducerApp {
+ public static void main(String[] args) {
+ SpringApplication.run(ProducerApp.class, args);
+ }
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/config/ApplicationConfig.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/config/ApplicationConfig.java
new file mode 100644
index 00000000..11858f6f
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/config/ApplicationConfig.java
@@ -0,0 +1,81 @@
+package ru.demo.config;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.kafka.clients.admin.NewTopic;
+import org.apache.kafka.clients.producer.ProducerConfig;
+import org.apache.kafka.common.serialization.StringSerializer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.autoconfigure.kafka.KafkaProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.kafka.config.TopicBuilder;
+import org.springframework.kafka.core.DefaultKafkaProducerFactory;
+import org.springframework.kafka.core.KafkaTemplate;
+import org.springframework.kafka.core.ProducerFactory;
+import org.springframework.kafka.support.JacksonUtils;
+import org.springframework.kafka.support.serializer.JsonSerializer;
+import ru.demo.model.StringValue;
+import ru.demo.service.DataSender;
+import ru.demo.service.DataSenderKafka;
+import ru.demo.service.StringValueSource;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+
+@Configuration
+public class ApplicationConfig {
+ private static final Logger log = LoggerFactory.getLogger(ApplicationConfig.class);
+ public final String topicName;
+
+ public ApplicationConfig(@Value("${application.kafka.topic}") String topicName) {
+ this.topicName = topicName;
+ }
+
+ @Bean
+ public ObjectMapper objectMapper() {
+ return JacksonUtils.enhancedObjectMapper();
+ }
+
+ @Bean
+ public ProducerFactory producerFactory(
+ KafkaProperties kafkaProperties, ObjectMapper mapper) {
+ var props = kafkaProperties.buildProducerProperties();
+ props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, StringSerializer.class);
+ props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, JsonSerializer.class);
+
+ var kafkaProducerFactory = new DefaultKafkaProducerFactory(props);
+ kafkaProducerFactory.setValueSerializer(new JsonSerializer<>(mapper));
+ return kafkaProducerFactory;
+ }
+
+ @Bean
+ public KafkaTemplate kafkaTemplate(
+ ProducerFactory producerFactory) {
+ return new KafkaTemplate<>(producerFactory);
+ }
+
+ @Bean
+ public NewTopic topic() {
+ return TopicBuilder.name(topicName).partitions(1).replicas(1).build();
+ }
+
+ @Bean
+ public DataSender dataSender(NewTopic topic, KafkaTemplate kafkaTemplate) {
+ return new DataSenderKafka(
+ topic.name(),
+ kafkaTemplate,
+ stringValue -> log.info("asked, value:{}", stringValue));
+ }
+
+ @Bean(value = "sourceExecutor", destroyMethod = "close")
+ public ScheduledExecutorService sourceExecutor() {
+ return Executors.newScheduledThreadPool(1);
+ }
+
+ @Bean
+ public StringValueSource stringValueSource(DataSender dataSender, ScheduledExecutorService sourceExecutor) {
+ return new StringValueSource(dataSender, sourceExecutor);
+ }
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/model/StringValue.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/model/StringValue.java
new file mode 100644
index 00000000..213f1309
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/model/StringValue.java
@@ -0,0 +1,3 @@
+package ru.demo.model;
+
+public record StringValue(long id, String value) {}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSender.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSender.java
new file mode 100644
index 00000000..321e3f5f
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSender.java
@@ -0,0 +1,7 @@
+package ru.demo.service;
+
+import ru.demo.model.StringValue;
+
+public interface DataSender {
+ void send(StringValue value);
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSenderKafka.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSenderKafka.java
new file mode 100644
index 00000000..a1b07f80
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/DataSenderKafka.java
@@ -0,0 +1,48 @@
+package ru.demo.service;
+
+import java.util.function.Consumer;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.kafka.core.KafkaTemplate;
+import ru.demo.model.StringValue;
+
+public class DataSenderKafka implements DataSender {
+ private static final Logger log = LoggerFactory.getLogger(DataSenderKafka.class);
+
+ private final KafkaTemplate template;
+
+ private final Consumer sendAsk;
+
+ private final String topic;
+
+ public DataSenderKafka(
+ String topic,
+ KafkaTemplate template,
+ Consumer sendAsk) {
+ this.topic = topic;
+ this.template = template;
+ this.sendAsk = sendAsk;
+ }
+
+ @Override
+ public void send(StringValue value) {
+ try {
+ log.info("value:{}", value);
+ template.send(topic, value)
+ .whenComplete(
+ (result, ex) -> {
+ if (ex == null) {
+ log.info(
+ "message id:{} was sent, offset:{}",
+ value.id(),
+ result.getRecordMetadata().offset());
+ sendAsk.accept(value);
+ } else {
+ log.error("message id:{} was not sent", value.id(), ex);
+ }
+ });
+ } catch (Exception ex) {
+ log.error("send error, value:{}", value, ex);
+ }
+ }
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/Runner.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/Runner.java
new file mode 100644
index 00000000..16c25602
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/Runner.java
@@ -0,0 +1,18 @@
+package ru.demo.service;
+
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.stereotype.Service;
+
+@Service
+public class Runner implements CommandLineRunner {
+ private final ValueSource valueSource;
+
+ public Runner(ValueSource valueSource) {
+ this.valueSource = valueSource;
+ }
+
+ @Override
+ public void run(String... args) {
+ valueSource.generate();
+ }
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/StringValueSource.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/StringValueSource.java
new file mode 100644
index 00000000..4c474f4c
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/StringValueSource.java
@@ -0,0 +1,33 @@
+package ru.demo.service;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import ru.demo.model.StringValue;
+
+public class StringValueSource implements ValueSource {
+ private static final Logger log = LoggerFactory.getLogger(StringValueSource.class);
+ private final AtomicLong nextValue = new AtomicLong(1);
+ private final DataSender valueConsumer;
+ private final ScheduledExecutorService executor;
+
+
+ public StringValueSource(DataSender dataSender, ScheduledExecutorService executor) {
+ this.valueConsumer = dataSender;
+ this.executor = executor;
+ }
+
+ @Override
+ public void generate() {
+ executor.scheduleAtFixedRate(() -> valueConsumer.send(makeValue()), 0, 1, TimeUnit.SECONDS);
+ log.info("generation started");
+ }
+
+ private StringValue makeValue() {
+ var id = nextValue.getAndIncrement();
+ return new StringValue(id, "stVal:" + id);
+ }
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/ValueSource.java b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/ValueSource.java
new file mode 100644
index 00000000..1204f5e6
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/java/ru/demo/service/ValueSource.java
@@ -0,0 +1,5 @@
+package ru.demo.service;
+
+public interface ValueSource {
+ void generate();
+}
diff --git a/2025-03/spring-38-kafka/producer/src/main/resources/application.yml b/2025-03/spring-38-kafka/producer/src/main/resources/application.yml
new file mode 100644
index 00000000..72fa1f46
--- /dev/null
+++ b/2025-03/spring-38-kafka/producer/src/main/resources/application.yml
@@ -0,0 +1,11 @@
+application:
+ kafka:
+ topic: "demo-topic"
+
+spring:
+ kafka:
+ producer:
+ bootstrap-servers: "127.0.0.1:9092"
+ client-id: "demo-producer"
+
+