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~
