SpringData【Spring整合HibernateJPA】

我就是我 2022-01-30 05:45 233阅读 0赞

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">
    	
    	
    	<context:property-placeholder location="classpath:jdbc.properties"/>
    	
    	
    	<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>
    
    	
    	<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">
    				
    				
    				<property name="database" value="MYSQL"/>
    				
    				<property name="generateDdl" value="true"/>
    				
    				<property name="showSql" value="true"/>
    			</bean>
    		</property>
    		
    		<property name="packagesToScan">
    			<list>
    				<value>com.dpb.pojo</value>
    			</list>
    		</property>
    	</bean>
    	
    	<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    		<property name="entityManagerFactory" ref="entityManagerFactory"/>
    	</bean>
    	
    	
    	<tx:annotation-driven transaction-manager="transactionManager"/>
    	
    	
    	<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);
            }
        }
    }

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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~

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