JPA 7. Spring 整合 JPA

Bertha 。 2022-05-21 07:17 179阅读 0赞

# Spring 整合 JPA #

## 三种整合方式 ##

*  LocalEntityManagerFactoryBean：适用于那些仅使用 JPA 进行数据访问的项目，该 FactoryBean 将根据JPA PersistenceProvider 自动检测配置文件进行工作，一般从“META-INF/persistence.xml”读取配置信息，这种方式最简单，但不能设置 Spring 中定义的DataSource，且不支持 Spring 管理的全局事务
 *  从JNDI中获取：用于从 Java EE 服务器获取指定的EntityManagerFactory，这种方式在进行 Spring 事务管理时一般要使用 JTA 事务管理
 *  LocalContainerEntityManagerFactoryBean：适用于所有环境的 FactoryBean，能全面控制 EntityManagerFactory 配置,如指定 Spring 定义的 DataSource 等等。

## 示例: ##

*  pom.xml

<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.ifox.hgx</groupId> <artifactId>jpa_ Integrated_spring</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>jpa_ Integrated_spring Maven Webapp</name>  <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> </properties> <dependencies>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>5.0.3.RELEASE</version> </dependency>  <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>5.2.13.Final</version> </dependency>  <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-entitymanager</artifactId> <version>5.2.13.Final</version> </dependency>  <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.38</version> </dependency>  <dependency> <groupId>com.mchange</groupId> <artifactId>c3p0</artifactId> <version>0.9.5.2</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> </dependencies>

*  数据库连接信息:db.properties

jdbc.url = jdbc:mysql://localhost:3306/JPA
    jdbc.user = root
    jdbc.password = 123456
    jdbc.driverClass = com.mysql.jdbc.Driver

*  spring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/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    
    
        
        <context:component-scan base-package="com.ifox.hgx.jpa.spring"></context:component-scan>
    
        
        <context:property-placeholder location="classpath:db.properties"></context:property-placeholder>
    
        <bean class="com.mchange.v2.c3p0.ComboPooledDataSource" id="dataSource">
            <property name="jdbcUrl" value="${jdbc.url}"></property>
            <property name="driverClass" value="${jdbc.driverClass}"></property>
            <property name="user" value="${jdbc.user}"></property>
            <property name="password" value="${jdbc.password}"></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.ifox.hgx.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>

*  Person.java 实体类

@Table(name = "JPA_PERSON") @Entity public class Person { private Integer id ; private String lastName ; private String email ; private Integer age ; public Person() { } public Person(String lastName, String email, Integer age) { this.lastName = lastName; this.email = email; this.age = age; } // @GeneratedValue(strategy = GenerationType.IDENTITY) @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 Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return "Person{" + "id=" + id + ", lastName='" + lastName + '\'' + ", email='" + email + '\'' + ", age=" + age + '}'; } }

*  Dao层:PersonDao

package com.ifox.hgx.jpa.spring.dao; import com.ifox.hgx.jpa.spring.entities.Person; import org.springframework.stereotype.Repository; import org.springframework.transaction.annotation.Transactional; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; @Repository public class PersonDao { //标注成员变量 @PersistenceContext private EntityManager entityManager ; @Transactional public void save(Person person){ entityManager.persist(person); } }

*  Service层: PersonService

package com.ifox.hgx.jpa.spring.service; import com.ifox.hgx.jpa.spring.dao.PersonDao; import com.ifox.hgx.jpa.spring.entities.Person; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; @Service public class PersonService { @Autowired private PersonDao personDao ; public void save(Person person, Person person2){ personDao.save(person); personDao.save(person2); } }

*  测试类:JPATest

package com.ifox.hgx.jap.spring; import com.ifox.hgx.jpa.spring.entities.Person; import com.ifox.hgx.jpa.spring.service.PersonService; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import javax.sql.DataSource; import java.sql.Connection; public class JPATest { private ApplicationContext applicationContext = null ; private PersonService personService = null ; { applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml") ; personService = applicationContext.getBean(PersonService.class) ; } @Test public void testDataSource() throws Exception{ DataSource dataSource = applicationContext.getBean(DataSource.class) ; Connection connection = dataSource.getConnection(); System.out.println(connection); } @Test public void testPersonSave(){ Person person = new Person("AAA","12132@qq.com",13) ; Person person1 = new Person("BBB","12312@qq.com",23) ; personService.save(person,person1); } }

*  目录结构:

![目录结构][70]

[70]: /images/20220521/ded4c3448a3242c68b79b46a667b6673.png