JPA学习 —— 第二课、spring整合JPA （不完全版 -- 手动控制事务）

刺骨的言语ヽ痛彻心扉 2022-05-25 02:08 219阅读 0赞

这里是使用spring整合JPA，而且是不完全版，纯属是因为测试方便。

如果想看原始的没用spring整合的JPA配置，请去这里: [创建JPA项目][JPA]

## **1. 依赖配置** ##

<properties>
            <mysql.version>5.1.34</mysql.version>
            <spring.version>4.3.0.RELEASE</spring.version>
            <hibernate.version>4.1.0.Final</hibernate.version>
            <querydsl.version>4.1.4</querydsl.version>
            <jackson.version>2.5.4</jackson.version>
        </properties>
        <dependencies>
            
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>javax.servlet-api</artifactId>
                <version>3.1.0</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-beans</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-core</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context-support</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-orm</artifactId>
                <version>${spring.version}</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-test</artifactId>
                <version>${spring.version}</version>
            </dependency>
            
    
            
            
            <dependency>
                <groupId>com.mchange</groupId>
                <artifactId>c3p0</artifactId>
                <version>0.9.5.2</version>
            </dependency>
            
    
            
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
                <version>${hibernate.version}</version>
            </dependency>
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-entitymanager</artifactId>
                <version>${hibernate.version}</version>
            </dependency>
            
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
    
    
            
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
            
            
            <dependency>
                <groupId>org.apache.commons</groupId>
                <artifactId>commons-lang3</artifactId>
                <version>3.3.2</version>
            </dependency>
            
        </dependencies>

## **2.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:jpa="http://www.springframework.org/schema/data/jpa" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd">
    
        
        <context:property-placeholder location="classpath:jdbc.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.ssj.domain"></property>
            <property name="jpaProperties">
                <props>
                    <prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
                    
                    <prop key="hibernate.hbm2ddl.auto">update</prop>
                    
                    <prop key="hibernate.show_sql">true</prop>
                    
                    <prop key="hibernate.format_sql">true</prop>
                    <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                     
    
                </props>
            </property>
        </bean>
    </beans>

1.这里配置了 JPA 的 EntityManagerFactory，用来获取实体管理器EntityManage，EntityManage相当于hibernate的session，其中包含大量的接口用来操控实体实现对数据库的操作。  
2.其实spring整合hibernate是将session交给spring容器管理，而spring整合JPA就是将EntityManage交给spring容器管理。

## **3.创建实体类** ##

package com.ssj.domain;
    
    import java.util.Date;
    
    import javax.persistence.*;
    
    @Entity
    @Table(name="employee")
    public class Employee { 
    
        @Column(name="ID")
        @GeneratedValue(strategy=GenerationType.IDENTITY)
        @Id
        private Integer Id;
    
        @Column(name="EMP_NAME")
        private String empName;
    
        @Column(name="EMP_BIRTH")
        @Temporal(TemporalType.DATE)
        private Date empBirth;
    
    
        public Integer getId() {
            return Id;
        }
        public void setId(Integer id) {
            Id = id;
        }
        public String getEmpName() {
            return empName;
        }
        public void setEmpName(String empName) {
            this.empName = empName;
        }
    
        public Date getEmpBirth() {
            return empBirth;
        }
        public void setEmpBirth(Date empBirth) {
            this.empBirth = empBirth;
        }
        @Override
        public String toString() {
            return "Employee [Id=" + Id + ", empName=" + empName + ", empBirth="
                    + empBirth + "]";
        }
    }

## **4.测试类** ##

package com.ssj.test;
    
    import java.util.Date;
    
    import javax.persistence.EntityManager;
    import javax.persistence.EntityManagerFactory;
    import javax.persistence.EntityTransaction;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.test.context.ContextConfiguration;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
    
    import com.ssj.domain.Employee;
    
    @RunWith(SpringJUnit4ClassRunner.class)  
    @ContextConfiguration(locations= "classpath:applicationContext.xml") 
    public class Test01 {
    
        @Autowired
        private EntityManagerFactory entityManagerFactory;
    
        @Test
        public void test1(){        
             //2. 创建EntityManager
            EntityManager em = entityManagerFactory.createEntityManager();
    
            //3.开启事务
            EntityTransaction transaction = em.getTransaction();
            transaction.begin();
            Employee emp = new Employee();
            emp.setEmpName("张三");
            emp.setEmpBirth(new Date());
    
            em.persist(emp);
    
             //5. 提交事务
            transaction.commit();
    
            //6. 关闭EntityManager
            em.close();
        }
    }

## **5.运行结果** ##

![这里写图片描述][70]  
新建了表  
![这里写图片描述][70 1]

[JPA]: https://blog.csdn.net/u010837612/article/details/47612149
[70]: /images/20220525/21b7a6094ab2480e9fe576c00aadb026.png
[70 1]: /images/20220525/fda7a972531741eda5a7b1f8447a5216.png