1.导入依赖 hibernate 这个依赖自带实现JPA接口
XML
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.4.32.Final</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.47</version>
</dependency>
</dependencies>2.在resources目录下建立 META-INF文件夹 ，创建JPA persistence.xml配置文件
persistence.xml
XML
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">
<!-- 需要配置persistence-unit 节点
持久化单元:
name: 持久化单元名称 可随时切换， 若是OpenJPA的实现方式就 换成 OpenJPA 就可以了
transaction-type: 事务管理方式
JTA:分布式事务管理
RESOURCE_LOCAL:本地事务管理
-->
<persistence-unit name="hibernateJPA" transaction-type="RESOURCE_LOCAL">
<!--JPA 的 实现方式 顺序别搞错，要放在class上面 -->
<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
<!--需要进行ORM 的POJO类 -->
<class>com.kuang.pojo.Customer</class>
<!-- 可选配置 :配置 JPA 实现方 的 配置信息 -->
<properties>
<!-- 数据库信息
用户名 , javax.persistence.jdbc.user
密码 , javax.persistence.jdbc.password
驱动 , javax.persistence.jdbc.driver
数据库地址 , javax.persistence.jdbc.url
-->
<property name="javax.persistence.jdbc.user" value="root"/>
<property name="javax.persistence.jdbc.password" value="2001"/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/springdata_jpa?useUnicode=true&useSSL=false&characterEncoding=UTF-8"/>
<!-- 配置JPA实现方 (hibernate) 的配置信息
显示sql : false|true
自动创建数据库表: hibernate.hbm2ddl.auto
create: 程序运行时创建数据库表（如果有表，先删除在创建）
update: 程序运行时创建表（如果有表，不会创建表）
none: 不会创建表
-->
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.hbm2ddl.auto" value="update"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQL57InnoDBDialect"/>
</properties>
</persistence-unit>
</persistence>3.创建测试类
java
package com.kuang.test;
import com.kuang.pojo.Customer;
import org.junit.Before;
import org.junit.Test;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.xml.soap.SAAJMetaFactory;
public class JpaTest {
private EntityManagerFactory factory;
@Before
public void before() {
//EntityManagerFactory 创建工厂 对应 sqlSessionFactory 用来创建 entityManager
factory = Persistence.createEntityManagerFactory("hibernateJPA");
}
@Test
public void insert() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
Customer customer = new Customer();
customer.setCustName("刘备");
customer.setCustAddress("锦州");
entityManager.persist(customer);
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void select() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
Customer customer = entityManager.find(Customer.class, 1L);
// Customer customer = entityManager.getReference(Customer.class, 1L);//延迟查询
// System.out.println("=======");
System.out.println(customer);
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void update() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
Customer customer = new Customer();
customer.setCustId(9L);
customer.setCustName("lzl");
customer.setCustAddress("为鲁斯");
/**
* 如果指定了主键:
* 更新 :1. 先查询 看是否有变化
* *如果有变化 更新 如果没有变化 就不更新
* 如果没有指定主键:
* 插入:
*/
//存在即修改, 不存在就添加
//注意： 修改是覆盖操作，你没给的值，就全给你覆盖为null
// 如果你不想让他查一遍,你可以自己写JPQL语句进行添加或者修改
Customer merge = entityManager.merge(customer);
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void update_JPQL() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
String jpql="update Customer set custName=:custName , custAddress=:custAddress where custId=:id";
entityManager.createQuery(jpql)
.setParameter("custName","张杰")
.setParameter("custAddress","广东")
.setParameter("id",3L)
.executeUpdate();
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void test_SQL() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
String sql="update tb_customer set cust_name=:custName , cust_address=:custAddress where cust_id=:id";
entityManager.createNativeQuery(sql)
.setParameter("custName","谢娜")
.setParameter("custAddress","湖南")
.setParameter("id",3L)
.executeUpdate();
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void delete() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
Customer customer = entityManager.find(Customer.class, 3L);
entityManager.remove(customer);// 这样删除，是删除游离状态的，会抛异常不允许这样操作 IllegalArgumentException: Removing a detached instance com.kuang.pojo.Customer#3
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
@Test
public void template() {
//其实底层实现还是hibernate
// entityManager 相当于 sqlSession 代码与数据库之间的桥梁
EntityManager entityManager = null;
EntityTransaction transaction=null;
try {
entityManager = factory.createEntityManager();
transaction = entityManager.getTransaction();//获取事务对象
transaction.begin();//事务开启
transaction.commit();//事务提交
} catch (Exception e) {
e.printStackTrace();
transaction.rollback();//事务回滚
} finally {
if (entityManager!=null){
entityManager.close();//关闭连接
}
}
}
}