标签：spring data
https://en.wikibooks.org/wiki/Java_Persistence/What_is_JPA%3F
https://en.wikipedia.org/wiki/Java_Persistence_API
表 CREATE TABLE `Employee` ( `id` int(11) unsigned NOT NULL, `name` varchar(20) DEFAULT NULL, `role` varchar(20) DEFAULT NULL, PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
2.1项目结构
2.2 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>org.springframework</groupId> <artifactId>gs-relational-data-access</artifactId> <version>0.1.0</version> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> </dependencies> <repositories> <repository> <id>spring-releases</id> <name>Spring Releases</name> <url>https://repo.spring.io/libs-release</url> </repository> <repository> <id>org.jboss.repository.releases</id> <name>JBoss Maven Release Repository</name> <url>https://repository.jboss.org/nexus/content/repositories/releases</url> </repository> </repositories> <pluginRepositories> <pluginRepository> <id>spring-releases</id> <name>Spring Releases</name> <url>https://repo.spring.io/libs-release</url> </pluginRepository> </pluginRepositories> <dependencyManagement> <dependencies> <dependency> <groupId>io.spring.platform</groupId> <artifactId>platform-bom</artifactId> <version>1.1.2.RELEASE</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> </project>
使用了platform-bom，方便了包的依赖管理。
依赖树结构
2.3 persistence.xml
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"> <persistence-unit name="JPAExamples"> <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider> </persistence-unit> </persistence>
2.4 spring.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:p="http://www.springframework.org/schema/p" 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/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"> <!--数据源--> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="url" value="jdbc:mysql://localhost:3306/exampledb"/> <property name="username" value="root"/> <property name="password" value="root"/> <property name="driverClassName" value="com.mysql.jdbc.Driver"/> </bean> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="persistenceXmlLocation" value="META-INF/persistence.xml"/> <property name="persistenceUnitName" value="JPAExamples"/> <property name="jpaVendorAdapter" ref="jpaVendorAdapter"/> <property name="jpaDialect" ref="jpaDialect"/> <property name="jpaProperties"> <props> <prop key="hibernate.show_sql">true</prop> </props> </property> </bean> <bean id="jpaVendorAdapter" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <property name="generateDdl" value="false" /> <property name="database" value="MYSQL"/> </bean> <bean id="jpaDialect" class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/> <bean id="entityManager" factory-bean="entityManagerFactory" factory-method="createEntityManager"></bean> <!-- Jpa 事务管理器 --> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" p:entityManagerFactory-ref="entityManagerFactory" /> <!-- 开启注解事务 --> <tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true" /> <!-- 启动对@AspectJ（面向切面）注解的支持 --> <aop:aspectj-autoproxy /> <context:component-scan base-package="com.journaldev.spring.jpa"></context:component-scan> </beans>
有的对象，不是必须的。为了保持完整性，做了保留。
可以配置entityManagerFactory的packagesToScan属性，没有配置也是可以的。
2.5 entity
package com.journaldev.spring.jpa.model;
import javax.persistence.Entity;
import javax.persistence.Id;
@Entity
public class Employee {
@Id
private int id;
private String name;
private String role;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getRole() {
return role;
}
public void setRole(String role) {
this.role = role;
}
@Override
public String toString() {
return "{ID=" + id + ",Name=" + name + ",Role=" + role + "}";
}
}2.6 接口
public interface EmployeeDAO {
//Create
public void save(Employee employee);
//Read
public Employee getById(int id);
//Update
public void update(Employee employee);
//Delete
public void deleteById(int id);
//Get All
public List<Employee> getAll();
}package com.journaldev.spring.jpa.dao;
import com.journaldev.spring.jpa.model.Employee;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.transaction.Transactional;
import java.util.List;
/**
* Created by zhaoguoyu on 2016/6/22.
*/
@Transactional
@Repository
public class EmployeeDAOImpl implements EmployeeDAO {
@PersistenceContext
EntityManager em;
@Override
public void save(Employee employee) {
em.persist(employee);
}
@Override
public Employee getById(int id) {
return em.find(Employee.class, id);
}
public void update(Employee employee) {
em.merge(employee);
}
@Override
public void deleteById(int id) {
em.remove(this.getById(id));
}
@Override
public List<Employee> getAll() {
CriteriaBuilder builder =em.getCriteriaBuilder();
final CriteriaQuery<Employee> query = builder.createQuery(Employee.class);
return this.em.createQuery(query).getResultList();
}
}2.7测试
测试类
import com.journaldev.spring.jpa.dao.EmployeeDAO;
import com.journaldev.spring.jpa.model.Employee;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import javax.annotation.Resource;
import java.util.Random;
/**
* Created by zhaoguoyu on 2016/6/22.
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:spring.xml")
public class SpringJPATest extends AbstractTransactionalJUnit4SpringContextTests {
@Resource
private EmployeeDAO employeeDAO;
@Test
public void testSave(){
Employee emp = new Employee();
int rand = new Random().nextInt(1000);
emp.setId(rand);
emp.setName("Pankaj");
emp.setRole("Java Developer");
employeeDAO.save(emp);
}
@Test
public void testUpdate(){
Employee emp = new Employee();
int rand = new Random().nextInt(1000);
emp.setId(rand);
emp.setName("Pankaj");
emp.setRole("Java Developer");
employeeDAO.save(emp);
emp.setName(emp.getName()+"_update");
employeeDAO.update(emp);
}
}OR
import com.journaldev.spring.jpa.dao.EmployeeDAO;
import com.journaldev.spring.jpa.model.Employee;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import java.util.Random;
/**
* Created by zhaoguoyu on 2016/6/22.
*/
public class Main {
public static void main(String[] args) {
ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("spring.xml");
final EmployeeDAO employeeDAO = ctx.getBean(EmployeeDAO.class);
Employee emp = new Employee();
int rand = new Random().nextInt(1000);
emp.setId(rand);
emp.setName("Pankaj");
emp.setRole("Java Developer");
employeeDAO.save(emp);
Employee employee = employeeDAO.getById(rand);
employee.setName(employee.getName() +"_update");
employeeDAO.update(employee);
}
}有一点需要说明。默认使用的日志是logback.号称比log4j更优秀的一款。
默认的日志配置logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<layout class="ch.qos.logback.classic.PatternLayout">
<Pattern>
%d{yyyy-MM-dd HH:mm:ss} [%thread] %-5level %logger{36} - %msg%n
</Pattern>
</layout>
</appender>
<logger name="org.hibernate" level="debug" additivity="false">
<appender-ref ref="STDOUT" />
</logger>
<root level="error">
<appender-ref ref="STDOUT" />
</root>
</configuration>总结
本文主要讲解了Spring对JPA的支持，和演示了整合过程。其中JPA的内容还有很多，不可能在本文全部讲完。本系列主要是为大家提供以递进的方式，通过前后的演示对比，感觉Spring DATA API的强大。
通过JPA的整合，实现了访问数据库，完全不需要写SQL。这样的好处之一：实现了SQL的透明，可以无缝实现不同数据库厂商和数据库版本间的切换。Spring 对JPA的支持还没有结束
本文出自 “简单” 博客，请务必保留此出处http://dba10g.blog.51cto.com/764602/1791946
Spring Data 系列(二) Spring+JPA入门
标签：spring data
原文地址：http://dba10g.blog.51cto.com/764602/1791946
