Spring Data JPA 入门案例

Spring Data JPA 入门案例

1.打开IDEA工具的界面如图所示，点击Create New Project。 2.选择Maven工程和JDK的版本，并点击Next。如图所示： 3.填写项目名称和保存的地址，点击Finish。如图所示： 4.导入相应的依赖jar包的代码如下：

<?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.txw</groupId> <artifactId>jpa-day02</artifactId> <version>1.0-SNAPSHOT</version> <!--锁定版本号--> <properties> <spring.version>5.0.2.RELEASE</spring.version> <hibernate.version>5.0.7.Final</hibernate.version> <slf4j.version>1.6.6</slf4j.version> <log4j.version>1.2.12</log4j.version> <c3p0.version>0.9.1.2</c3p0.version> <mysql.version>5.1.6</mysql.version> </properties> <dependencies> <!-- junit单元测试 --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> <!-- spring beg --> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.6.8</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</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-context-support</artifactId> <version>${spring.version}</version> </dependency> <!-- spring对orm框架的支持包--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${spring.version}</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> <!-- spring end --> <!-- hibernate beg --> <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>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.2.1.Final</version> </dependency> <!-- hibernate end --> <!-- c3p0 beg --> <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>${c3p0.version}</version> </dependency> <!-- c3p0 end --> <!-- log end --> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>${log4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>${slf4j.version}</version> </dependency> <!-- log end --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!-- spring data jpa 的坐标--> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-jpa</artifactId> <version>1.9.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</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 --> <!--导入lombok依赖jar包--> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.12</version> </dependency> </dependencies> </project>

5.在resources目录下创建applicationContext.xml的配置文件代码如下：

<?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:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:task="http://www.springframework.org/schema/task" 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.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.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"> <!--spring 和 spring data jpa的配置--> <!-- 1.创建entityManagerFactory对象交给spring容器管理--> <bean id="entityManagerFactoty" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource" /> <!--配置的扫描的包（实体类所在的包） --> <property name="packagesToScan" value="com.txw.domain" /> <!-- jpa的实现厂家 --> <property name="persistenceProvider"> <bean class="org.hibernate.jpa.HibernatePersistenceProvider"/> </property> <!--jpa的供应商适配器 --> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <!--配置是否自动创建数据库表 --> <property name="generateDdl" value="false" /> <!--指定数据库类型 --> <property name="database" value="MYSQL" /> <!--数据库方言：支持的特有语法 --> <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" /> <!--是否显示sql --> <property name="showSql" value="true" /> </bean> </property> <!--jpa的方言 ：高级的特性 --> <property name="jpaDialect" > <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" /> </property> </bean> <!--2.创建数据库连接池 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="user" value="root"></property> <property name="password" value="123456"></property> <property name="jdbcUrl" value="jdbc:mysql:///jpa?characterEncoding=utf-8" ></property> <property name="driverClass" value="com.mysql.jdbc.Driver"></property> </bean> <!--3.整合spring dataJpa--> <jpa:repositories base-package="com.txw.dao" transaction-manager-ref="transactionManager" entity-manager-factory-ref="entityManagerFactoty" ></jpa:repositories> <!--4.配置事务管理器 --> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactoty"></property> </bean> <!-- 5. 配置包扫描--> <context:component-scan base-package="com.txw" ></context:component-scan> </beans>

6.创建客户实体类并配置映射关系的代码如下：

package com.txw.domain; import lombok.Data; import lombok.ToString; import javax.persistence.*; import java.io.Serializable; /** * 客户的实体类 * 配置映射关系 * 1.实体类和表的映射关系 * @Entity:声明实体类 * @Table : 配置实体类和表的映射关系 * name : 配置数据库表的名称 * 2.实体类中属性和表中字段的映射关系 * @author: Adair */ @Entity @Table(name = "cst_customer") @Data // 自动生成set和get方法 @ToString // 重写toString方法 @SuppressWarnings("all") // 注解警告信息 public class Customer implements Serializable { /** * @Id：声明主键的配置 * @GeneratedValue:配置主键的生成策略 * strategy * GenerationType.IDENTITY ：自增，mysql * * 底层数据库必须支持自动增长（底层数据库支持的自动增长方式，对id自增） * GenerationType.SEQUENCE : 序列，oracle * * 底层数据库必须支持序列 * GenerationType.: jpa提供的一种机制，通过一张数据库表的形式帮助我们完成主键自增 * GenerationType.AUTO ： 由程序自动的帮助我们选择主键生成策略 * @Column:配置属性和字段的映射关系 * name：数据库表中字段的名称 */ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "cust_id") private Long custId; // 客户的主键 @Column(name = "cust_name") private String custName; // 客户名称 @Column(name="cust_source") private String custSource; // 客户来源 @Column(name="cust_level") private String custLevel; // 客户级别 @Column(name="cust_industry") private String custIndustry; // 客户所属行业 @Column(name="cust_phone") private String custPhone; // 客户的联系方式 @Column(name="cust_address") private String custAddress; // 客户地址 }

7.编写符合spring Data JPA规范的dao层接口的代码如下：

package com.txw.dao; import com.txw.domain.Customer; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.data.jpa.repository.JpaSpecificationExecutor; /** * 符合SpringDataJpa的dao层接口规范 * JpaRepository<操作的实体类类型，实体类中主键属性的类型> * 封装了基本CRUD操作 * JpaSpecificationExecutor<操作的实体类类型> * 封装了复杂查询（分页） * @author: Adair */ @SuppressWarnings("all") // 注解警告信息 public interface CustomerDao extends JpaRepository<Customer,Long>, JpaSpecificationExecutor<Customer> { }

8.完成客户的查询操作的代码如下：

package com.txw.test; import com.txw.dao.CustomerDao; import com.txw.domain.Customer; 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; /** * 测试CRUD的操作 * @author: Adair */ @RunWith(SpringJUnit4ClassRunner.class) //声明spring提供的单元测试环境 @ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息 @SuppressWarnings("all") // 注解警告信息 public class CustomerDaoTest { // 声明CustomerDao业务对象 @Autowired // 自动注入 private CustomerDao customerDao; /** * 根据id查询 */ @Test public void testFindOne() { Customer customer = customerDao.findOne(4l); System.out.println(customer); } }

运行结果如图所示： 9.完成客户的添加和修改的代码如下：

package com.txw.test; import com.txw.dao.CustomerDao; import com.txw.domain.Customer; 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; /** * 测试CRUD的操作 * @author: Adair */ @RunWith(SpringJUnit4ClassRunner.class) //声明spring提供的单元测试环境 @ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息 @SuppressWarnings("all") // 注解警告信息 public class CustomerDaoTest { // 声明CustomerDao业务对象 @Autowired // 自动注入 private CustomerDao customerDao; /** * save : 保存或者更新 * 根据传递的对象是否存在主键id， * 如果没有id主键属性：保存 * 存在id主键属性，根据id查询数据，更新数据 */ @Test public void testSave() { Customer customer = new Customer(); customer.setCustName("Adair"); customer.setCustLevel("vip"); customer.setCustIndustry("笔记2"); customerDao.save(customer); } @Test public void testUpdate() { Customer customer = new Customer(); customer.setCustId(4l); customer.setCustName("Adair1"); customerDao.save(customer); } }

运行结果如图所示： 10.完成客户的删除的代码如下：

package com.txw.test; import com.txw.dao.CustomerDao; 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; /** * 测试CRUD的操作 * @author: Adair */ @RunWith(SpringJUnit4ClassRunner.class) //声明spring提供的单元测试环境 @ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息 @SuppressWarnings("all") // 注解警告信息 public class CustomerDaoTest { // 声明CustomerDao业务对象 @Autowired // 自动注入 private CustomerDao customerDao; /** *根据id删除 */ @Test public void testDelete () { customerDao.delete(4l); } }

运行之前数据库的数据如图所示： 运行java代码的结果如图所示： 运行之后数据库的数据如图所示： 11.查询所有客户的测试代码如下：

package com.txw.test; import com.txw.dao.CustomerDao; import com.txw.domain.Customer; 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 java.util.List; /** * 测试CRUD的操作 * @author: Adair */ @RunWith(SpringJUnit4ClassRunner.class) //声明spring提供的单元测试环境 @ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息 @SuppressWarnings("all") // 注解警告信息 public class CustomerDaoTest { // 声明CustomerDao业务对象 @Autowired // 自动注入 private CustomerDao customerDao; /** * 查询所有 */ @Test public void testFindAll() { List<Customer> list = customerDao.findAll(); for(Customer customer : list) { System.out.println(customer); } } }

运行结果如图所示：