Hibernate中使用Spring Data JPA

一、配置文件的方式

1、pom.xml中引入相关依赖

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>

<dependencies>

<!-- Spring data jpa依赖 -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.11.4.RELEASE</version>
</dependency>

<!-- hibernate依赖 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.1.7.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.1.7.Final</version>
</dependency>

<!-- mysql依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.42</version>
</dependency>

<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>

2、JPA配置MATE-INF/persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="myjpa" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<class>com.wyl.bean.User</class>
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/test"/>
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="root"/>

<property name=" hibernate.show_sql" value="true"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
</properties>
</persistence-unit>
</persistence>

3、创建实体对象User.class

package com.wyl.bean;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="users")
public class User {
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Integer id;

@Column
private String userName;

@Column
private String phone;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
@Override
public String toString() {
// TODO Auto-generated method stub
return super.toString();
}
}

4、创建测试类

package com.wyl;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.junit.Test;

import com.wyl.bean.User;

public class JpaTest {

private EntityManagerFactory factory = Persistence.createEntityManagerFactory("myjpa");

@Test
public void testAdd(){
EntityManager em = factory.createEntityManager();
User user = new User();
user.setUserName("wang");
user.setPhone("123422222222");

em.getTransaction().begin(); //事务开启

try {
em.persist(user);  //持久化数据
em.getTransaction().commit(); //事务提交
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
em.getTransaction().rollback(); //事务回滚
} finally {
em.close(); //关闭em
}
}

@Test
public void testFind(){
EntityManager em = factory.createEntityManager();
User user = em.find(User.class, 1);
System.out.println(user.getUserName());
em.getTransaction().begin(); //事务开启
try {
em.merge(user);
em.getTransaction().commit(); //事务提交
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
em.getTransaction().rollback(); //事务回滚
} finally {
em.close(); //关闭em
}
}

@Test
public void testDelete(){
EntityManager em = factory.createEntityManager();

User user = em.find(User.class, 1); //查询到实体

em.getTransaction().begin(); //事务开启
try {
em.remove(user);  //删除实体
em.getTransaction().commit(); //事务提交
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
em.getTransaction().rollback(); //事务回滚
} finally {
em.close(); //关闭em
}
}
}

二、配置类的方式

实现步骤：

　　1、加入Spring data jpa的依赖
　　2、加入数据库驱动依赖
　　3、加入jpa实现的依赖（hibernate）
 　 4、定义Entity
　　5、在spring容器中，定义三个Bean（ DataSource、EntityManagerFactory、PlatformTransactionManager）
　　6、定义Repository
　　7、操作

1、引入相关依赖

　　　　<!-- spring-data-jpa依赖 -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.11.4.RELEASE</version>
</dependency>

<!-- mysql依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.42</version>
</dependency>

<!-- hibernate依赖 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>5.1.7.Final</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.1.7.Final</version>
</dependency>

2、创建实体类

　　同上面一样

3、jpa配置类

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
import org.springframework.transaction.PlatformTransactionManager;

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

/*
* 配置类，相当于spring中的xml文件
* */
@Configuration
public class JPAConfiguration {

/*
*配置数据源
*/
@Bean
public DataSource createDataSource(){
MysqlDataSource dataSource = new MysqlDataSource();
dataSource.setURL("jdbc:mysql://127.0.0.1:3306/test");
dataSource.setUser("root");
dataSource.setPassword("root");
return dataSource;
}

/*
* 配置EntityManager
*/
@Bean("entityManagerFactory")
public EntityManagerFactory createEntityManager(DataSource dataSource){
LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
em.setDataSource(dataSource); //配置数据源

HibernateJpaVendorAdapter jpaVendorAdapter = new HibernateJpaVendorAdapter();
jpaVendorAdapter.setGenerateDdl(true);
jpaVendorAdapter.setShowSql(true);

em.setPackagesToScan("com.wyl.bean");//设置实体类的扫描路径
em.setJpaVendorAdapter(jpaVendorAdapter); //配置jpa的适配器
em.afterPropertiesSet();
return em.getObject();
}

/*
* 定义一个事务
*/
@Bean("transactionManager")
public PlatformTransactionManager createPlatformTransactionManager(EntityManagerFactory emf){
JpaTransactionManager tm = new JpaTransactionManager();
tm.setEntityManagerFactory(emf);
return tm;
}
}

4、创建数据库操作接口

import org.springframework.data.repository.CrudRepository;

import com.wyl.bean.User;

public interface UserRepository extends CrudRepository<User, Integer> {

}

定义Repository的方法：

　　方法一：继承接口：Repository、CrudRepository、PagingAndSortingRepository、　　　　　　　　　JpaRepository

　　方法二：使用@RepositoryDefinition注解

不生成Repository的实现类，使用@NoRepositoryBean注解。

5、测试

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import com.wyl.bean.User;
import com.wyl.jpa.UserRepository;

@ComponentScan
@EnableJpaRepositories
public class App
{
public static void main( String[] args )
{
AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(App.class);
UserRepository repository = context.getBean(UserRepository.class);

　　　　 User user = new User();
user.setPhone("10086");
user.setUserName("shaya");

　　　　 repository.save(user);

　　　　 context.close();

}
}