jpa学习和jpa与spring整合（二）

淡淡的烟草味﹌ 2022-06-13 06:46 177阅读 0赞

经过上一篇介绍了jpa的用法和原理：这一篇开始整合jpa与spring整合。

**一.配置applicationContext.xml**

<?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: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-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
         <context:component-scan base-package="com.atguigu.jpa"></context:component-scan>
        <context:property-placeholder location="classpath:db.properties"/>
       <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
          <property name="user" value="${jdbc.user}"></property>
          <property name="password" value="${jdbc.password}"></property>
          <property name="driverClass" value="${jdbc.driverClass}"></property>
          <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>   
           </bean>
       <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
          <property name="dataSource" ref="dataSource"></property>
           <property name="jpaVendorAdapter">
             <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"></bean>
          </property>
           <property name="packagesToScan" value="com.atguigu.jpa.spring.entities"></property>
           <property name="jpaProperties">
             <props>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.format_sql">true</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
             </props>
          </property>
       </bean>
         <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
          <property name="entityManagerFactory" ref="entityManagerFactory"></property>   
       </bean>
       
        <tx:annotation-driven transaction-manager="transactionManager"/>
    
    </beans>

二.配置数据库连接db.properties
     jdbc.user=root jdbc.password=1230 jdbc.driverClass=com.mysql.jdbc.Driver jdbc.jdbcUrl=jdbc:mysql:///jpa三.配置架包

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**四.PersonDao**

package com.atguigu.jpa.dao;
    import javax.persistence.EntityManager;
    import javax.persistence.PersistenceContext;
    import org.springframework.stereotype.Repository;
    import com.atguigu.jpa.spring.entities.Person;
    @Repository
    public class PersonDao {
       //如何获取到和当前事务关联的 EntityManager 对象呢 ? //通过 @PersistenceContext 注解来标记成员变量! @PersistenceContext
       private EntityManager entityManager;
       public void save(Person person){
          entityManager.persist(person);
       }
    }

**五.service**

package com.atguigu.jpa.service;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.transaction.annotation.Transactional;
    import com.atguigu.jpa.dao.PersonDao;
    import com.atguigu.jpa.spring.entities.Person;
    @Service
    public class PersonService {
       @Autowired
       private PersonDao personDao;
       @Transactional
       public void savePersons(Person p1, Person p2){
          personDao.save(p1);
          int i = 10 / 0;
          personDao.save(p2);
       }
    }

**六.model**

package com.atguigu.jpa.spring.entities;
    import javax.persistence.Column;
    import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.Id;
    import javax.persistence.Table;
    @Table(name="JPA_PERSONS")
    @Entity
    public class Person {
       private Integer id;
       private String lastName;
       private String email;
       private int age;
       @GeneratedValue
       @Id
       public Integer getId() {
          return id;
       }
       public void setId(Integer id) {
          this.id = id;
       }
       @Column(name="LAST_NAME")
       public String getLastName() {
          return lastName;
       }
       public void setLastName(String lastName) {
          this.lastName = lastName;
       }
       public String getEmail() {
          return email;
       }
       public void setEmail(String email) {
          this.email = email;
       }
       public int getAge() {
          return age;
       }
       public void setAge(int age) {
          this.age = age;
       }
    }

**七.test**

package com.atguigu.jpa.spring;
    import java.sql.SQLException;
    import javax.sql.DataSource;
    import org.junit.Test;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import com.atguigu.jpa.service.PersonService;
    import com.atguigu.jpa.spring.entities.Person;
    public class JPATest {
       private ApplicationContext ctx = null;
       private PersonService personService = null;
       {
          ctx = new ClassPathXmlApplicationContext("applicationContext.xml");
          personService = ctx.getBean(PersonService.class);
       }
       @Test
       public void testPersonService(){
          Person p1 = new Person();
          p1.setAge(11);
          p1.setEmail("aa@163.com");
          p1.setLastName("AA");
          
          Person p2 = new Person();
          p2.setAge(12);
          p2.setEmail("bb@163.com");
          p2.setLastName("BB");
          System.out.println(personService.getClass().getName());
          personService.savePersons(p1, p2);
       }
       @Test
       public void testDataSource() throws SQLException {
          DataSource dataSource = ctx.getBean(DataSource.class);
          System.out.println(dataSource.getConnection());
       }
    }

后续会不断完善

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