主要的结构目录：
创建Role.java
package cn.itcast.domain;
import javax.persistence.*;
import java.util.HashSet;
import java.util.Set;
@Entity
@Table(name = "sys_role")
public class Role {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "role_id")
private Long roleId;
@Column(name = "role_name")
private String roleName;
/**
*配置多对多
*/
@ManyToMany(targetEntity = User.class)//配置多表关系
@JoinTable(name= "sys_user_role"
//joinColumns,当前对象在中间表的外键
,joinColumns = {@JoinColumn(name = "sys_role_id",referencedColumnName = "role_id")}
//inverseJoinColumns，对方对象在中间表的外键
,inverseJoinColumns = {@JoinColumn(name = "sys_user_id",referencedColumnName = "user_id")})
private Set<User> users=new HashSet<User>();
public Long getRoleId() {
return roleId;
}
public void setRoleId(Long roleId) {
this.roleId = roleId;
}
public String getRoleName() {
return roleName;
}
public void setRoleName(String roleName) {
this.roleName = roleName;
}
public Set<User> getUsers() {
return users;
}
public void setUsers(Set<User> users) {
this.users = users;
}
}
主要的User.java
package cn.itcast.domain;
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)
* targetEntity:代表对方的实体类字节码
* 2、配置中间表（包含两个外键）
* name：中间表的名称
* joinColumns,当前对象在中间表的外键
* name：外键名
* referencedColumnName：参照的主表的主键名
* inverseJoinColumns，对方对象在中间表的外键
* name：外键名
* referencedColumnName：
*/
@ManyToMany(targetEntity = Role.class,cascade = CascadeType.ALL)
@JoinTable(name= "sys_user_role"
//joinColumns,当前对象在中间表的外键
,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<Role>();
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;
}
}
主要的RoleDao.java
public interface RoleDao extends JpaRepository<Role,Long>,JpaSpecificationExecutor<Role> {
}
主要的UserDao.java
public interface UserDao extends JpaRepository<User,Long>,JpaSpecificationExecutor<User> {
}
在配置applicationContext.xml中
<?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"
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的配置-->
<!-- 1.创建entityManagerFactory对象交给spring容器管理-->
<bean id="entityManagerFactoty" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<!--配置的扫描的包（实体类所在的包） -->
<property name="packagesToScan" value="cn.itcast.domain" />
<!-- jpa的实现厂家 -->
<property name="persistenceProvider">
<bean class="org.hibernate.jpa.HibernatePersistenceProvider"/>
</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="false" />
<!--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 -->
<property name="showSql" value="true" />
</bean>
</property>
<!--jpa的方言 ：高级的特性 -->
<property name="jpaDialect" >
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" />
</property>
<!--注入jpa的配置信息
加载jpa的基本配置信息和jpa实现方式（hibernate）的配置信息
hibernate.hbm2ddl.auto : 自动创建数据库表
create ： 每次都会重新创建数据库表
update：有表不会重新创建，没有表会重新创建表
-->
<property name="jpaProperties" >
<props>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
</bean>
<!--2.创建数据库连接池 -->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="user" value="root"></property>
<property name="password" value="root"></property>
<property name="jdbcUrl" value="jdbc:mysql:///jpa" ></property>
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
</bean>
<!--3.整合spring dataJpa-->
<jpa:repositories base-package="cn.itcast.dao" transaction-manager-ref="transactionManager"
entity-manager-factory-ref="entityManagerFactoty" ></jpa:repositories>
<!--4.配置事务管理器 -->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactoty"></property>
</bean>
<!-- 4.txAdvice-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<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(* cn.itcast.service.*.*(..))" />
<aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" />
</aop:config>
<!--5.声明式事务 -->
<!-- 6. 配置包扫描-->
<context:component-scan base-package="cn.itcast" ></context:component-scan>
</beans>
保存一个用户，保存一个角色
主要的applicationContext.xml中
<property name="jpaProperties" >
<props>
<prop key="hibernate.hbm2ddl.auto">create</prop>
</props>
</property>
@Test
@Transactional
@Rollback(false)
public void testAdd(){
User user = new User();
user.setUserName("小李");
Role role = new Role();
role.setRoleName("java程序员");
user.getRoles().add(role);
userDao.save(user);
roleDao.save(role);
}
测试中
//测试级联添加
@Test
@Transactional
@Rollback(false)
public void testCadeAdd(){
User user = new User();
user.setUserName("小李");
Role role = new Role();
role.setRoleName("java程序员");
user.getRoles().add(role);
userDao.save(user);
//roleDao.save(role);
}
//测试级联删除
@Test
@Transactional
@Rollback(false)
public void testCadeRemove(){
//查询1号用户
User user = userDao.findOne(1l);
//删除1号用户
userDao.delete(user);
}
在测试中主要spring配置中的问题，主要是配置中不能出问题。在这些中主要调用的是接口中继承的两个类，所以前面也介绍了继承的两个类中的方法