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>
原文:https://www.cnblogs.com/yscec/p/12008843.html