SpringData【Spring整合HibernateJPA】

  本文在上一篇‘Spring整合hibernate’的基础上来介绍下Spring整合HibernateJPA的内容，

Spring整合HibernateJPA

一、什么是JPA

  现如今的ORM框架还是比较多的比如Hibernate，TopLink以及OpenJPA等等，为了简化ORM框架的使用，JPA随之产生。
  JPA是Java Persistence API的简称，中文名Java持久层API，由 Sun 公司提供了一对对于持久层操作的标准(接口+文档),说白了就是在各种ORM框架之上封装了一套API实现统一操作。同时又依赖各种ORM框架去实现。hibernate3.2版本后提供了对JPA的实现。本文就具体来介绍下怎么使用

二、整合HibernateJPA

1.创建maven项目

  创建一个普通maven工程(jar)

2.引入相关的依赖

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>4.3.21.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.aspectj</groupId>
        <artifactId>aspectjweaver</artifactId>
        <version>1.6.8.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.3</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>5.0.7.Final</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>4.3.21.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.32</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>4.3.21.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>5.0.7.Final</version>
    </dependency>
</dependencies>

3.添加配置文件

jdbc.url=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8
jdbc.driver.class=com.mysql.jdbc.Driver
jdbc.username=root
jdbc.password=123456

<?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:context="http://www.springframework.org/schema/context"
  xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
  xsi:schemaLocation="http://www.springframework.org/schema/beans 
  http://www.springframework.org/schema/beans/spring-beans.xsd
  http://www.springframework.org/schema/context
  http://www.springframework.org/schema/context/spring-context.xsd
  http://www.springframework.org/schema/aop
  http://www.springframework.org/schema/aop/spring-aop.xsd
  http://www.springframework.org/schema/tx 
  http://www.springframework.org/schema/tx/spring-tx.xsd">
  
  <!-- 配置读取properties文件的工具类 -->
  <context:property-placeholder location="classpath:jdbc.properties"/>
  
  <!-- 配置c3p0数据库连接池 -->
  <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="jdbcUrl" value="${jdbc.url}"/>
    <property name="driverClass" value="${jdbc.driver.class}"/>
    <property name="user" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
  </bean>

  <!-- Spring 整合 JPA 配置 EntityManagerFactory-->
  <bean id="entityManagerFactory"
      class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <property name="jpaVendorAdapter">
      <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
        <!-- hibernate 相关的属性的注入 -->
        <!-- 配置数据库类型 -->
        <property name="database" value="MYSQL"/>
        <!-- 正向工程 自动创建表 -->
        <property name="generateDdl" value="true"/>
        <!-- 显示执行的 SQL -->
        <property name="showSql" value="true"/>
      </bean>
    </property>
    <!-- 扫描实体的包 -->
    <property name="packagesToScan">
      <list>
        <value>com.dpb.pojo</value>
      </list>
    </property>
  </bean>
  <!-- 配置 Hibernate 的事务管理器 -->
  <bean id="transactionManager"
      class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory"
          ref="entityManagerFactory"/>
  </bean>
  
  <!-- 配置开启注解事务处理 -->
  <tx:annotation-driven transaction-manager="transactionManager"/>
  
  <!-- 配置springIOC的注解扫描 -->
  <context:component-scan base-package="com.dpb"/>
</beans>

4.添加pojo

/**
 * @program: spring-hibernate-jpa
 * @description: Users的Pojo对象
 * @author: 波波烤鸭
 * @create: 2019-05-18 09:37
 */

@Entity
@Table(name="users")
public class Users implements Serializable {

    @Id
    @GeneratedValue(strategy= GenerationType.IDENTITY)//strategy=GenerationType.IDENTITY 自增长
    @Column(name="userid")
    private Integer userid;

    @Column(name="username")
    private String username;

    @Column(name="userage")
    private Integer userage;

    public Integer getUserid() {
        return userid;
    }

    public void setUserid(Integer userid) {
        this.userid = userid;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public Integer getUserage() {
        return userage;
    }

    public void setUserage(Integer userage) {
        this.userage = userage;
    }

    @Override
    public String toString() {
        return "Users [userid=" + userid + ", username=" + username + ", userage=" + userage + "]";
    }

}

5.Dao接口和实现

/**
 * 定义接口中的方法
 */
public interface UserDao {

    void insertUsers(Users users);

    void updateUsers(Users users);

    void deleteUsers(Users users);

    Users selectUsersById(Integer userid);

    List<Users> selectUserByName(String username);

    List<Users> selectUserByNameUseSQL(String username);

    List<Users> selectUserByNameUseCriteria(String username);
}

import org.springframework.stereotype.Repository;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import java.util.List;

/**
 * @program: spring-hibernate
 * @description: 用户持久层的实现类
 * @author: 波波烤鸭
 * @create: 2019-05-18 09:43
 */
@Repository
public class UserDaoImpl implements UserDao {

    @PersistenceContext(name="entityManagerFactory")
    private EntityManager entityManager;

    @Override
    public void insertUsers(Users users) {
        this.entityManager.persist(users);
    }

    @Override
    public void updateUsers(Users users) {
        this.entityManager.merge(users);
    }

    @Override
    public void deleteUsers(Users users) {
        Users  u = this.selectUsersById(users.getUserid());
        this.entityManager.remove(u);
    }

    @Override
    public Users selectUsersById(Integer userid) {
        return this.entityManager.find(Users.class, userid);
    }

    @Override
    public List<Users> selectUserByName(String username) {
        return this.entityManager.createQuery(" from Users where username = :abc").setParameter("abc", username).getResultList();
    }

    @Override
    public List<Users> selectUserByNameUseSQL(String username) {
        //在Hibernate JPA中 如果通过？方式来帮顶参数，那么他的查数是从1开始的。而hibernate中是从0开始的。
        return this.entityManager.createNativeQuery("select * from t_users where username = ?", Users.class).setParameter(1, username).getResultList();
    }

    @Override
    public List<Users> selectUserByNameUseCriteria(String username) {
        //CriteriaBuilder对象：创建一个CriteriaQuery,创建查询条件。
        CriteriaBuilder builber = this.entityManager.getCriteriaBuilder();
        //CriteriaQuery对象：执行查询的Criteria对象
        //select  * from t_users
        CriteriaQuery<Users> query = builber.createQuery(Users.class);
        //获取要查询的实体类的对象
        Root<Users> root = query.from(Users.class);
        //封装查询条件
        Predicate cate = builber.equal(root.get("username"), username);
        //select * from t_users where username = 张三
        query.where(cate);
        //执行查询
        TypedQuery<Users> typeQuery = this.entityManager.createQuery(query);
        return typeQuery.getResultList();
    }
}

6.单元测试

/**
 * @program: spring-hibernate
 * @description: 单元测试
 * @author: 波波烤鸭
 * @create: 2019-05-18 09:48
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class TestDemo {

    @Autowired
    private UserDao usersDao;


    /**
     * 添加用户
     */
    @Test
    @Transactional// 在测试类对于事务提交方式默认的是回滚。
    @Rollback(false)//取消自动回滚
    public void testInsertUsers(){
        Users users = new Users();
        users.setUserage(20);
        users.setUsername("张三-jpa");
        this.usersDao.insertUsers(users);
    }

    /**
     * 更新用户
     */
    @Test
    @Transactional
    @Rollback(false)
    public void testUpdateUsers(){
        Users users = new Users();
        users.setUserid(2);
        users.setUserage(22);
        users.setUsername("李四");
        this.usersDao.updateUsers(users);
    }

    /**
     * 根据userid查询用户
     */
    @Test
    public void testSelectUsersById(){
        Users users = this.usersDao.selectUsersById(2);
        System.out.println(users);
    }

    /**
     * 删除用户
     */
    @Test
    @Transactional
    @Rollback(false)
    public void testDeleteUsers(){
        Users users = new Users();
        users.setUserid(2);
        this.usersDao.deleteUsers(users);
    }

    /**
     * HQL测试
     */
    @Test
    @Transactional
    public void testSelectUserByName(){
        List<Users> list = this.usersDao.selectUserByName("张三");
        for (Users users : list) {
            System.out.println(users);
        }
    }

    /**
     * SQL测试
     */
    @Test
    @Transactional
    public void testSelectUserByNameUseSQL(){
        List<Users> list = this.usersDao.selectUserByNameUseSQL("张三");
        for (Users users : list) {
            System.out.println(users);
        }
    }

    /**
     * Criteria测试
     */
    @Test
    @Transactional
    public void testSelectUserByNameUseCriteria(){
        List<Users> list = this.usersDao.selectUserByNameUseCriteria("张三");
        for (Users users : list) {
            System.out.println(users);
        }
    }
}

注意：本文是在上一篇文章的基础上整合的hibernateJPA，所以很多描述就省略掉了~