这里简单的介绍一下使用maven工程创建SpringDataJPA的开发环境的搭建
首先引入依赖
<dependencies>
<!-- junit单元测试 -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!--spring使用aop需要引入的一个包-->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.9</version>
</dependency>
<!--mysql驱动包-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.39</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager
这个是实体类管理
-->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.4.1.Final</version>
</dependency>
<!--连接池-->
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-jpa -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>2.1.5.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.1.5.RELEASE</version>
</dependency> <!-- el beg 使用spring data jpa 必须引入 -->
<dependency>
<groupId>javax.el</groupId>
<artifactId>javax.el-api</artifactId>
<version>2.2.4</version>
</dependency> <dependency>
<groupId>org.glassfish.web</groupId>
<artifactId>javax.el</artifactId>
<version>2.2.4</version>
</dependency>
<!-- el end --> <dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>3.20.0-GA</version>
</dependency>
</dependencies>
编写配置文件
<?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:tx="http://www.springframework.org/schema/tx"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa.xsd"> <!--
1.配置数据源
2.配置entityManagerFactory对象
3.事务
4.jpa
-->
<!--1.配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql:///springdatajpa"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
<!--2.配置entityManagerFactory-->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<!--配置数据源-->
<property name="dataSource" ref="dataSource"></property>
<!--配置jpaVendorAdapter适配器-->
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="database" value="MYSQL"></property>
</bean>
</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>
<property name="packagesToScan" value="com.qingmu.domain"></property>
</bean>
<!--3.配置事务-->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<tx:annotation-driven></tx:annotation-driven>
<!--配置JPA-->
<jpa:repositories base-package="com.qingmu.dao"
entity-manager-factory-ref="entityManagerFactory"
transaction-manager-ref="transactionManager">
</jpa:repositories>
</beans>
使用JPA注解配置映射关系(在实体类中)
package com.qingmu.domain; import javax.persistence.*; /**
* @Auther:qingmu
* @Description:脚踏实地,只为出人头地
* @Date:Created in 20:21 2019/5/15
*/
@Entity
@Table(name = "x_user")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "x_id")
private Long id;
@Column(name = "x_age")
private int age;
@Column(name = "x_name")
private String name; public Long getId() {
return id;
} public void setId(Long id) {
this.id = id;
} public int getAge() {
return age;
} public void setAge(int age) {
this.age = age;
} public String getName() {
return name;
} public void setName(String name) {
this.name = name;
} public Customer() {
} public Customer(int age, String name) { this.age = age;
this.name = name;
} @Override
public String toString() {
return "Customer{" +
"id=" + id +
", age=" + age +
", name='" + name + '\'' +
'}';
}
}
创建一个Dao层接口，并实现JpaRepository和JpaSpecificationExecutor
提供相应的泛型
package com.qingmu.dao; import com.qingmu.domain.Customer; import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor; /**
* @Auther:qingmu
* @Description:脚踏实地,只为出人头地
* @Date:Created in 20:48 2019/5/15
*/
public interface UserDao extends JpaSpecificationExecutor<Customer>,JpaRepository<Customer,Long> {
}
进行测试
package com.qingmu; import com.qingmu.dao.UserDao;
import com.qingmu.domain.Customer;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional; import java.util.Optional; /**
* @Auther:qingmu
* @Description:脚踏实地,只为出人头地
* @Date:Created in 20:49 2019/5/15
*/
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:beans.xml")
public class CustomerTest01 {
@Autowired
private UserDao userDao; @Test
@Rollback(false)
@Transactional
public void saveTest(){
Customer customer = new Customer();
customer.setId(1L);
customer.setName("太阳");
customer.setAge(38);
userDao.save(customer);
}
@Test
@Rollback(false)
@Transactional
public void updateTest(){
Customer customer = new Customer(37,"调养");
customer.setId(1L);
userDao.save(customer);
}
@Test
@Transactional
@Rollback(false)
public void testFind1(){
/**
* Optional 是jdk1.8 新增的一个类 用来避免空指针的
*
* 自己程序中 如果养成好习惯 都会做判空运算
* User user=xxx();
* if(user!=null){
* //写自己的逻辑
* }
* Optional 就是一个包装盒子 里面放对象
*/
Optional<Customer> userDaoById = userDao.findById(1L);
Customer customer = userDaoById.get();
System.out.println(customer);
/**if(optional.isPresent()){
* User user = optional.get();
* * System.out.println(user);
}*/
//官方 推荐使用手法
}
@Test
@Transactional
@Rollback(false)
public void testFind2(){
Customer one = userDao.getOne(1L);
System.out.println(one);
}
@Test
@Transactional
@Rollback(false)
public void testDele(){
Customer customer = userDao.findById(1L).get(); userDao.delete(customer);
}
}