spring data jpa 多对多查询

2023-08-30 14:45:40

package com.ytkj.dao;

import com.ytkj.entity.Customer;

import com.ytkj.entity.Role;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/**

 * JpaRepository<实体类类型，主键类型>：用来完成基本CRUD操作

 * JpaSpecificationExecutor<实体类类型>：用于复杂查询（分页等查询操作）

 */

public interface RoleDao extends JpaRepository<Role,Long>, JpaSpecificationExecutor<Role> {

}

package com.ytkj.dao;

import com.ytkj.entity.Customer;

import com.ytkj.entity.User;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/**

 * JpaRepository<实体类类型，主键类型>：用来完成基本CRUD操作

 * JpaSpecificationExecutor<实体类类型>：用于复杂查询（分页等查询操作）

 */

public interface UserDao extends JpaRepository<User,Long>, JpaSpecificationExecutor<User> {

}

package com.ytkj.dao;

import com.ytkj.entity.Customer;

import com.ytkj.entity.User;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.data.jpa.repository.JpaSpecificationExecutor;

/**

 * JpaRepository<实体类类型，主键类型>：用来完成基本CRUD操作

 * JpaSpecificationExecutor<实体类类型>：用于复杂查询（分页等查询操作）

 */

public interface UserDao extends JpaRepository<User,Long>, JpaSpecificationExecutor<User> {

}

package com.ytkj.entity;

import javax.persistence.*;

import java.util.HashSet;

import java.util.Set;

@Entity

@Table(name = "sys_user")

public class User {

    @Id

    @GeneratedValue(strategy = GenerationType.IDENTITY)

    @Column(name="user_id")

    private Long userId;

    @Column(name="user_name")

    private String userName;

    @Column(name="age")

    private Integer age;

    /**

     * 配置用户到角色的多对多关系

     *      配置多对多的映射关系

     *          1.声明表关系的配置

     *              @ManyToMany(targetEntity = Role.class)  //多对多

     *                  targetEntity：代表对方的实体类字节码

     *          2.配置中间表（包含两个外键）

     *                @JoinTable

     *                  name : 中间表的名称

     *                  joinColumns：配置当前对象在中间表的外键

     *                      @JoinColumn的数组

     *                          name：外键名

     *                          referencedColumnName：参照的主表的主键名

     *                  inverseJoinColumns：配置对方对象在中间表的外键

     */

    @ManyToMany(targetEntity = Role.class,cascade = CascadeType.ALL)

    @JoinTable(name = "sys_user_role",

            //joinColumns,当前对象在中间表中的外键

            joinColumns = {@JoinColumn(name = "sys_user_id",referencedColumnName = "user_id")},

            //inverseJoinColumns，对方对象在中间表的外键

            inverseJoinColumns = {@JoinColumn(name = "sys_role_id",referencedColumnName = "role_id")}

    )

    private Set<Role> roles = new HashSet<>();

    public Long getUserId() {

        return userId;

    }

    public void setUserId(Long userId) {

        this.userId = userId;

    }

    public String getUserName() {

        return userName;

    }

    public void setUserName(String userName) {

        this.userName = userName;

    }

    public Integer getAge() {

        return age;

    }

    public void setAge(Integer age) {

        this.age = age;

    }

    public Set<Role> getRoles() {

        return roles;

    }

    public void setRoles(Set<Role> roles) {

        this.roles = roles;

    }

}

import com.ytkj.dao.RoleDao;

import com.ytkj.dao.UserDao;

import com.ytkj.entity.Role;

import com.ytkj.entity.User;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.test.annotation.Rollback;

import org.springframework.test.context.ContextConfiguration;

import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import org.springframework.transaction.annotation.Transactional;

/**

 * 多对多测试 保存/删除操作

 */

@RunWith(SpringJUnit4ClassRunner.class)//声明spring提供的单元测试环境

@ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息

public class SpringdatajpaManyToManyTest {

    @Autowired

    private UserDao userDao;

    @Autowired

    private RoleDao roleDao;

    /**

     * 需求：

     * 	保存用户和角色

     * 要求：

     * 	创建2个用户和3个角色

     * 	让1号用户具有1号和2号角色(双向的)

     * 	让2号用户具有2号和3号角色(双向的)

     *  保存用户和角色

     * 问题：

     *  在保存时，会出现主键重复的错误，因为都是要往中间表中保存数据造成的。

     * 解决办法：

     * 	让任意一方放弃维护关联关系的权利

     */

    @Test

    @Transactional  //开启事务

    @Rollback(false)//设置为不回滚

    public void test(){

        //创建对象

        User u1 = new User();

        u1.setUserName("用户1");

        Role r1 = new Role();

        r1.setRoleName("角色1");

        //建立关联关系

        u1.getRoles().add(r1);

        r1.getUsers().add(u1);

        //保存

        roleDao.save(r1);

        userDao.save(u1);

    }

    /**

     * 删除操作

     * 	在多对多的删除时，双向级联删除根本不能配置

     * 禁用

     *	如果配了的话，如果数据之间有相互引用关系，可能会清空所有数据

     */

    @Test

    @Transactional

    @Rollback(false)//设置为不回滚

    public void testDelete() {

        userDao.delete(1l);

    }

}

<?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"

       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"

       xmlns:context="http://www.springframework.org/schema/context"

       xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx"

       xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:task="http://www.springframework.org/schema/task"

       xsi:schemaLocation="

        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd

        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd

        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd

        http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd

        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd

        http://www.springframework.org/schema/data/jpa

        http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">

    <!--spring和spring-data-jpa的整合-->

    <!--1.创建entityManagerFactory对象交给spring管理-->

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">

        <!--数据库注入-->

        <property name="dataSource" ref="dataSource"/>

        <!--配置包的扫描-->

        <property name="packagesToScan" value="com.ytkj.entity"/>

        <!--jpa实现厂家-->

        <property name="persistenceProvider">

            <bean class="org.hibernate.jpa.HibernatePersistenceProvider"></bean>

        </property>

        <!--JPA的供应商适配器-->

        <property name="jpaVendorAdapter">

            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">

                <!--配置是否自动创建数据库表-->

                <property name="generateDdl" value="true" />

                <!--指定数据库类型-->

                <property name="database" value="MYSQL" />

                <!--数据库方言：支持的特有语法-->

                <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" />

                <!--是否显示sql语句-->

                <property name="showSql" value="true" />

            </bean>

        </property>

        <!--jpa方言：高级特性-->

        <property name="jpaDialect">

            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />

        </property>

    </bean>

    <!--2.创建数据连接池-->

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

        <!--数据库信息-->

        <property name="driverClass" value="com.mysql.jdbc.Driver"/>

        <property name="jdbcUrl" value="jdbc:mysql://192.168.2.101:3306/ytkj?serverTimeZone=UTC"/>

        <property name="user" value="root"/>

        <property name="password" value="123456"/>

    </bean>

    <!--3.整合spring-data-jpa-->

    <jpa:repositories base-package="com.ytkj.dao" transaction-manager-ref="transacManager" entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>

    <!--4.配置事务管理器-->

    <bean id="transacManager" class="org.springframework.orm.jpa.JpaTransactionManager">

        <property name="entityManagerFactory" ref="entityManagerFactory" />

    </bean>

    <!--5.声明式事务-->

    <tx:advice id="txAdvice" transaction-manager="transacManager">

        <tx:attributes>

            <tx:method name="save*" propagation="REQUIRED"/>

            <tx:method name="insert*" propagation="REQUIRED"/>

            <tx:method name="update*" propagation="REQUIRED"/>

            <tx:method name="delete*" propagation="REQUIRED"/>

            <tx:method name="get*" read-only="true"/>

            <tx:method name="find*" read-only="true"/>

            <tx:method name="*" propagation="REQUIRED"/>

        </tx:attributes>

    </tx:advice>

    <!-- 5.aop-->

    <aop:config>

        <aop:pointcut id="pointcut" expression="execution(* com.ytkj.service.*.*(..))" />

        <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" />

    </aop:config>

    <context:component-scan base-package="com.ytkj"/>

</beans>

<?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>

    <groupId>com.ytkj</groupId>

    <artifactId>springdatajpa</artifactId>

    <version>1.0-SNAPSHOT</version>

    <properties>

        <spring.version>5.1.7.RELEASE</spring.version>

        <hibernate.version>5.0.7.Final</hibernate.version>

        <slf4j.version>1.6.6</slf4j.version>

        <log4j.version>1.2.12</log4j.version>

        <c3p0.version>0.9.1.2</c3p0.version>

        <mysql.version>5.1.6</mysql.version>

    </properties>

    <dependencies>

        <!-- junit单元测试 -->

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.9</version>

            <scope>test</scope>

        </dependency>

        <!-- spring beg -->

        <dependency>

            <groupId>org.aspectj</groupId>

            <artifactId>aspectjweaver</artifactId>

            <version>1.6.8</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-aop</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-context</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-context-support</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <!--spring对orm框架支持-->

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-orm</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-beans</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-core</artifactId>

            <version>${spring.version}</version>

        </dependency>

        <!-- spring end -->

        <!-- hibernate beg -->

        <dependency>

            <groupId>org.hibernate</groupId>

            <artifactId>hibernate-core</artifactId>

            <version>${hibernate.version}</version>

        </dependency>

        <dependency>

            <groupId>org.hibernate</groupId>

            <artifactId>hibernate-entitymanager</artifactId>

            <version>${hibernate.version}</version>

        </dependency>

        <dependency>

            <groupId>org.hibernate</groupId>

            <artifactId>hibernate-validator</artifactId>

            <version>5.2.1.Final</version>

        </dependency>

        <!-- hibernate end -->

        <!-- c3p0 beg -->

        <dependency>

            <groupId>c3p0</groupId>

            <artifactId>c3p0</artifactId>

            <version>${c3p0.version}</version>

        </dependency>

        <!-- c3p0 end -->

        <!-- log end -->

        <dependency>

            <groupId>log4j</groupId>

            <artifactId>log4j</artifactId>

            <version>${log4j.version}</version>

        </dependency>

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-api</artifactId>

            <version>${slf4j.version}</version>

        </dependency>

        <dependency>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-log4j12</artifactId>

            <version>${slf4j.version}</version>

        </dependency>

        <!-- log end -->

        <dependency>

            <groupId>mysql</groupId>

            <artifactId>mysql-connector-java</artifactId>

            <version>${mysql.version}</version>

        </dependency>

        <!--sprngdatajpa依赖-->

        <dependency>

            <groupId>org.springframework.data</groupId>

            <artifactId>spring-data-jpa</artifactId>

            <version>1.9.0.RELEASE</version>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-test</artifactId>

            <version>4.2.4.RELEASE</version>

        </dependency>

        <!-- el beg 使用spring data jpa 必须引入 -->

        <dependency>

            <groupId>javax.el</groupId>

            <artifactId>javax.el-api</artifactId>

            <version>2.2.4</version>

        </dependency>

        <dependency>

            <groupId>org.glassfish.web</groupId>

            <artifactId>javax.el</artifactId>

            <version>2.2.4</version>

        </dependency>

        <!-- el end -->

    </dependencies>

</project>

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