hibernate-fetch-mode-demo

2026-05-30 10:50:42 +00:00 · 2019-03-27 23:12:08 +03:00
parent 05d08b1f3e
commit 6620521317
19 changed files with 443 additions and 1 deletions
@@ -3,4 +3,5 @@
 ## Описание проектов

 * *unit-testing-plain-spring* - пример тестирования в проектах на чистом Spring
-* *unit-testing-spring-boot* - то же самое, только на Spring Boot
+* *unit-testing-spring-boot* - то же самое, только на Spring Boot
+* *hibernate-fetch-mode-demo* - демонстрация настроек Hibernate, в частности для решения проблемы N+1
@@ -0,0 +1,29 @@
+HELP.md
+/target/
+!.mvn/wrapper/maven-wrapper.jar
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+/build/
+
+### VS Code ###
+.vscode/
@@ -0,0 +1,71 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.1.3.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+    <groupId>ru.otus.example</groupId>
+    <artifactId>hibernate-fetch-mode-demo</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>HibernateFetchModeDemo</name>
+    <description>Demo project for Spring Boot</description>
+
+    <properties>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.shell</groupId>
+            <artifactId>spring-shell-starter</artifactId>
+            <version>2.0.0.RELEASE</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+    <repositories>
+        <repository>
+            <id>spring-milestones</id>
+            <name>Spring Milestones</name>
+            <url>https://repo.spring.io/milestone</url>
+        </repository>
+    </repositories>
+
+</project>
@@ -0,0 +1,13 @@
+package ru.otus.example.HibernateFetchModeDemo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class HibernateFetchModeDemoApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(HibernateFetchModeDemoApplication.class, args);
+	}
+
+}
@@ -0,0 +1,21 @@
+package ru.otus.example.HibernateFetchModeDemo.models;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+@Table(name = "knowledge")
+public class Knowledge {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column
+    private String name;
+}
@@ -0,0 +1,31 @@
+package ru.otus.example.HibernateFetchModeDemo.models;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.LazyCollection;
+import org.hibernate.annotations.LazyCollectionOption;
+
+import javax.persistence.*;
+import java.util.List;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+@Table(name = "mentors")
+public class Mentor {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column
+    private String name;
+
+    @LazyCollection(LazyCollectionOption.FALSE)
+    @ManyToMany(targetEntity = Knowledge.class, cascade = CascadeType.ALL)
+    @JoinTable(name = "mentors_experience",
+            joinColumns = @JoinColumn(name = "mentor_id", referencedColumnName = "id"),
+            inverseJoinColumns = @JoinColumn(name = "knowledge_id", referencedColumnName = "id"))
+    private List<Knowledge> experience;
+}
@@ -0,0 +1,34 @@
+package ru.otus.example.HibernateFetchModeDemo.models;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.BatchSize;
+import org.hibernate.annotations.LazyCollection;
+import org.hibernate.annotations.LazyCollectionOption;
+
+import javax.persistence.*;
+import java.util.List;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+@Table(name = "students")
+public class Student {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column
+    private String name;
+
+    //@BatchSize(size = 5)
+    @LazyCollection(LazyCollectionOption.FALSE)
+    @ManyToMany(targetEntity = Knowledge.class, cascade = CascadeType.ALL)
+    @JoinTable(name = "students_experience",
+            joinColumns = @JoinColumn(name = "student_id", referencedColumnName = "id"),
+            inverseJoinColumns = @JoinColumn(name = "knowledge_id", referencedColumnName = "id"))
+    private List<Knowledge> experience;
+
+}
@@ -0,0 +1,34 @@
+package ru.otus.example.HibernateFetchModeDemo.models;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.hibernate.annotations.Fetch;
+import org.hibernate.annotations.FetchMode;
+import org.hibernate.annotations.LazyCollection;
+import org.hibernate.annotations.LazyCollectionOption;
+
+import javax.persistence.*;
+import java.util.List;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+@Table(name = "teachers")
+public class Teacher {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    @Column
+    private String name;
+
+    @LazyCollection(LazyCollectionOption.FALSE)
+    @Fetch(FetchMode.SUBSELECT)
+    @ManyToMany(targetEntity = Knowledge.class, cascade = CascadeType.ALL)
+    @JoinTable(name = "teachers_experience",
+            joinColumns = @JoinColumn(name = "teacher_id", referencedColumnName = "id"),
+            inverseJoinColumns = @JoinColumn(name = "knowledge_id", referencedColumnName = "id"))
+    private List<Knowledge> experience;
+}
@@ -0,0 +1,9 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import ru.otus.example.HibernateFetchModeDemo.models.Mentor;
+
+import java.util.List;
+
+public interface MentorRepository {
+    List<Mentor> findAll();
+}
@@ -0,0 +1,20 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import org.springframework.stereotype.Repository;
+import ru.otus.example.HibernateFetchModeDemo.models.Mentor;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.util.List;
+
+@Repository
+public class MentorRepositoryImpl implements MentorRepository {
+
+    @PersistenceContext
+    private EntityManager em;
+
+    @Override
+    public List<Mentor> findAll() {
+        return em.createQuery("select m from Mentor m join fetch m.experience", Mentor.class).getResultList();
+    }
+}
@@ -0,0 +1,9 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import ru.otus.example.HibernateFetchModeDemo.models.Student;
+
+import java.util.List;
+
+public interface StudentRepository {
+    List<Student> findAll();
+}
@@ -0,0 +1,20 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import org.springframework.stereotype.Repository;
+import ru.otus.example.HibernateFetchModeDemo.models.Student;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.util.List;
+
+@Repository
+public class StudentRepositoryImpl implements StudentRepository {
+
+    @PersistenceContext
+    private EntityManager em;
+
+    @Override
+    public List<Student> findAll() {
+        return em.createQuery("select s from Student s", Student.class).getResultList();
+    }
+}
@@ -0,0 +1,9 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import ru.otus.example.HibernateFetchModeDemo.models.Teacher;
+
+import java.util.List;
+
+public interface TeacherRepository {
+    List<Teacher> findAll();
+}
@@ -0,0 +1,20 @@
+package ru.otus.example.HibernateFetchModeDemo.repositories;
+
+import org.springframework.stereotype.Repository;
+import ru.otus.example.HibernateFetchModeDemo.models.Teacher;
+
+import javax.persistence.EntityManager;
+import javax.persistence.PersistenceContext;
+import java.util.List;
+
+@Repository
+public class TeacherRepositoryImpl implements TeacherRepository {
+
+    @PersistenceContext
+    private EntityManager em;
+
+    @Override
+    public List<Teacher> findAll() {
+        return em.createQuery("select t from Teacher t", Teacher.class).getResultList();
+    }
+}
@@ -0,0 +1,48 @@
+package ru.otus.example.HibernateFetchModeDemo.shell;
+
+import org.springframework.shell.standard.ShellComponent;
+import org.springframework.shell.standard.ShellMethod;
+import ru.otus.example.HibernateFetchModeDemo.models.Mentor;
+import ru.otus.example.HibernateFetchModeDemo.models.Student;
+import ru.otus.example.HibernateFetchModeDemo.models.Teacher;
+import ru.otus.example.HibernateFetchModeDemo.repositories.MentorRepository;
+import ru.otus.example.HibernateFetchModeDemo.repositories.StudentRepository;
+import ru.otus.example.HibernateFetchModeDemo.repositories.TeacherRepository;
+
+import java.util.stream.Collectors;
+
+
+@ShellComponent
+public class ShellCommands {
+
+    private static final String OFFSET = "\n\n----------------------------\n\n";
+
+    private final StudentRepository studentRepository;
+    private final MentorRepository mentorRepository;
+    private final TeacherRepository teacherRepository;
+
+    public ShellCommands(StudentRepository studentRepository, MentorRepository mentorRepository, TeacherRepository teacherRepository) {
+        this.studentRepository = studentRepository;
+        this.mentorRepository = mentorRepository;
+        this.teacherRepository = teacherRepository;
+    }
+
+
+    @ShellMethod(value = "Show all students", key = "find-all-students")
+    public String findAllStudents(){
+        System.out.println();
+        return OFFSET + studentRepository.findAll().stream().map(Student::toString).collect(Collectors.joining("\n"));
+    }
+
+    @ShellMethod(value = "Show all mentors", key = "find-all-mentors")
+    public String findAllMentors(){
+        System.out.println();
+        return OFFSET + mentorRepository.findAll().stream().map(Mentor::toString).collect(Collectors.joining("\n"));
+    }
+
+    @ShellMethod(value = "Show all teachers", key = "find-all-teachers")
+    public String findAllTeachers(){
+        System.out.println();
+        return OFFSET + teacherRepository.findAll().stream().map(Teacher::toString).collect(Collectors.joining("\n"));
+    }
+}
@@ -0,0 +1,15 @@
+spring:
+  datasource:
+    url: jdbc:h2:mem:testdb
+    initialization-mode: always
+
+  jpa:
+    generate-ddl: false
+    hibernate:
+      ddl-auto: none
+
+    show-sql: true
+    properties:
+      hibernate:
+        #format_sql: true
+
@@ -0,0 +1,9 @@
+INSERT INTO knowledge (name) VALUES ('Spring Core'), ('Spring Data'), ('Spring MVC'), ('Spring Batch'), ('Spring Integration'), ('Spring WebFlux');
+
+INSERT INTO students (name) VALUES ('Student #01'), ('Student #02'), ('Student #03'), ('Student #04'), ('Student #05'), ('Student #06'), ('Student #07'), ('Student #08'), ('Student #09');
+INSERT INTO mentors (name) VALUES ('Mentor #01'), ('Mentor #02'), ('Mentor #03'), ('Mentor #04'), ('Mentor #05'), ('Mentor #06'), ('Mentor #07'), ('Mentor #08'), ('Mentor #09');
+INSERT INTO teachers (name) VALUES ('Teacher #01'), ('Teacher #02'), ('Teacher #03'), ('Teacher #04'), ('Teacher #05'), ('Teacher #06'), ('Teacher #07'), ('Teacher #08'), ('Teacher #09');
+
+INSERT INTO students_experience (student_id, knowledge_id) VALUES (1, 1), (1, 2), (2, 2), (2, 3), (2, 4), (2, 5);
+INSERT INTO mentors_experience  (mentor_id, knowledge_id)  VALUES (1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6);
+INSERT INTO teachers_experience (teacher_id, knowledge_id) VALUES(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6);
@@ -0,0 +1,48 @@
+DROP TABLE IF EXISTS students_experience;
+DROP TABLE IF EXISTS mentors_experience;
+DROP TABLE IF EXISTS teachers_experience;
+DROP TABLE IF EXISTS students;
+DROP TABLE IF EXISTS mentors;
+DROP TABLE IF EXISTS teachers;
+DROP TABLE IF EXISTS knowledge;
+
+CREATE TABLE knowledge (
+    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255),
+);
+
+CREATE TABLE students (
+    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255),
+);
+
+CREATE TABLE mentors (
+    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255),
+);
+
+CREATE TABLE teachers (
+    id BIGINT AUTO_INCREMENT PRIMARY KEY,
+    name VARCHAR(255),
+);
+
+CREATE TABLE students_experience (
+    student_id BIGINT,
+    knowledge_id BIGINT,
+    FOREIGN KEY(student_id) REFERENCES students(id) ON DELETE CASCADE,
+    FOREIGN KEY(knowledge_id) REFERENCES knowledge(id) ON DELETE CASCADE
+);
+
+CREATE TABLE mentors_experience (
+    mentor_id BIGINT,
+    knowledge_id BIGINT,
+    FOREIGN KEY(mentor_id) REFERENCES mentors(id) ON DELETE CASCADE,
+    FOREIGN KEY(knowledge_id) REFERENCES knowledge(id) ON DELETE CASCADE
+);
+
+CREATE TABLE teachers_experience (
+    teacher_id BIGINT,
+    knowledge_id BIGINT,
+    FOREIGN KEY(teacher_id) REFERENCES teachers(id) ON DELETE CASCADE,
+    FOREIGN KEY(knowledge_id) REFERENCES knowledge(id) ON DELETE CASCADE
+);
@@ -0,0 +1 @@
+