SpringData JPA(三) springDataJpa 概述及入门操作
1.SpringData Jpa 概述
Spring Data JPA 是Spring基于ORM思想,在JPA规范的基础上封装的一套JPA应用框架,是Spring提供的一套对JPA操作更加高级的封装,是在JPA规范下的专门用来进行数据持久化的解决方案。
可使开发者用极简的代码即可实现对数据库的访问和操作。它提供了包括增删改查等在内的常用功能,且易于扩展!学习并使用 Spring Data JPA 可以极大提高开发效率!
Spring Data JPA 让我们解脱了DAO层的操作,基本上所有CRUD都可以依赖于它来实现,在实际的工作工程中,推荐使用Spring Data JPA + ORM(如:hibernate)完成操作,这样在切换不同的ORM框架时提供了极大的方便,同时也使数据库层操作更加简单,方便解耦
2.SpringData Jpa 入门操作
1.创建Maven工程,导入依赖
2.配置Spring配置文件(配置SpringData 整合)
3.编写实体类,配置实体与表的映射关系
4.编写Dao层接口,继承JpaRepository,JpaSpecificationExecutor两接口
1)创建Maven工程,导入依赖
<properties>
<spring.version>4.2.4.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>4.9</version>
<scope>test</scope>
</dependency>
<!-- spring beg -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.6.8</version>
</dependency>
<!--aop-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<!--ioc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<!--核心包-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<!--spring orm 框架支持包-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<!--spring单元测试整合包-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</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>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.9.0.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 -->
</dependencies>
2)配置Spring配置文件(配置SpringData 整合)
jdbc.properties
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///jpa
jdbc.username=root
jdbc.password=123456
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: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">
<!--引入外部配置文件-->
<context:property-placeholder location="classpath*:jdbc.properties"/>
<!--1.
将entityManagerFactory 交给spring管理
LocalContainerEntityManagerFactoryBean
class:LocalContainerEntityManagerFactoryBean EntityManagerFactory接口 的实现类
-->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<!--注入数据源-->
<property name="dataSource" ref="dataSource"/>
<!--设置扫描包(实体类所在的包)-->
<property name="packagesToScan" value="com.xx.entity"/>
<!--设置jpa 的实现厂家-->
<property name="persistenceProvider">
<bean class="org.hibernate.jpa.HibernatePersistenceProvider"/>
</property>
<!--jpa供应商适配器-->
<property name="jpaVendorAdapter">
<!--Hibernate 供应商-->
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<!--连接数据库:MySQL-->
<property name="database" value="MYSQL"/>
<!--是否自动创建数据库表-->
<property name="generateDdl" value="false"/>
<!--配置数据库方言 支持该数据库的所有语法-->
<property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/>
<!--是否打印sql语句-->
<property name="showSql" value="true"/>
</bean>
</property>
<!--配置jpa方言-->
<property name="jpaDialect">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>
</property>
</bean>
<!--2.整合springData jpa
base-package:dao接口所在包
entity-manager-factory-ref:实体管理器
transaction-manager-ref:事务管理器
-->
<jpa:repositories base-package="com.xx.dao" entity-manager-factory-ref="entityManagerFactory"
transaction-manager-ref="transactionManager">
</jpa:repositories>
<!--3.配置数据源-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<!--4.配置事务管理器-->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<!--注入工厂-->
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<!--5.声明式事务-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<!--
REQUIRED: 必须让当前业务在事务的管理下,
如果没有事务就自动创建事务,如果又事务就是用当前事务
SUPPORTS: 事务可有可无,没有事务就不使用,有就使用
-->
<tx:attributes>
<tx:method name="save*" propagation="REQUIRED"/>
<tx:method name="insert*" propagation="REQUIRED"/>
<tx:method name="update*" propagation="REQUIRED"/>
<tx:method name="delete*" propagation="REQUIRED"/>
<tx:method name="get*" read-only="true"/>
<tx:method name="find*" read-only="true"/>
<tx:method name="*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice>
<!--6.配置包扫描-->
<context:component-scan base-package="com.xx"/>
</beans>
3)编写实体类
/**
* 客户实体类
*/
Entity
@Table(name = "t_cst_customer")
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "cust_id")
private Long custId;
@Column(name = "cust_name")
private String custName;
@Column(name = "cust_industry")
private String custIndustry;
@Column(name = "cust_source")
private String custSource;
@Column(name = "cust_level")
private String custLevel;
@Column(name = "cust_address")
private String custAddress;
@Column(name = "cust_phone")
private String custPhone;
4)简单查询
三种查询方式
- jpa api
- jpql/sql 查询
- @Query(nativeQuery=, value="")
- nativeQuery=true sql查询
- nativeQuery=false jqpl查询
- value="" 查询语句
- 命名规则查询
- 精准查询: findBy+实体属性名称
eg: findByCustName====> from 实体类名 where custName = ? - 模糊查询… : find+实体属性名称+查询方式(like|isNUll)
eg: findByCustNameLike====> from 实体类名 where custName like ? - 多条件查询: find + 实体属性名称 + 查询方式 + 连接符号(And|Or) 实体属性名称 + 查询方式…
eg: findByCustNameLikeAndCustIndustry ==> from 实体类名 where custName like ? and custIndustry = ?
- 精准查询: findBy+实体属性名称
4_v1_jpa api
4_v1_v1_Dao层
/**
* Customer 持久层接口
* 继承两个接口,提供相应的泛型
* JpaRepository<要操作实体类的类型, 主键属性类型>
* 封装了基础CRUD操作
* JpaSpecificationExecutor<要操作的实体类的类型>
* 封装了复杂查询
*/
public interface CustomerDao extends JpaRepository<Customer, Long> , JpaSpecificationExecutor<Customer>{
}
4_v1_v2_测试类
@RunWith(SpringJUnit4ClassRunner.class) //声明spring测试
@ContextConfiguration(locations = "classpath*:applicationContext.xml") //加载配置文件
public class test01 {
@Autowired
CustomerDao customerDao;
/**
* 根据id 查询指定客户
* findOne:立即加载
* find()
* getOne:延迟加载
* getReference 返回的是实体类的动态代理对象,什么时候使用,什么时候查询
*/
@Test
public void test_findOne(){
Customer customer = customerDao.findOne(3l);
System.out.println(customer);
}
@Test
@Transactional //使得方法测试顺利进行
public void test_getOne(){
Customer customer = customerDao.getOne(3l);
System.out.println(customer);
}
/**
* save() 保存/跟新客户
* 如果不存在主键属性,执行保存操作
* 如果存在主键属性,纤维根据主键查询数据库,再更新各值,
* 如果根据id无法查询出数据,则执行插入操作(主键依据主键生成策略生成)
*/
@Test
public void test_save(){
Customer customer = new Customer();
//customer.setCustId(8l);
customer.setCustName("张三集团");
customer.setCustLevel("vip");
customerDao.save(customer);
}
/**
* 先查询后更新
*/
@Test
public void test_update(){
Customer customer = customerDao.findOne(5l);
//customer.setCustId(8l);
customer.setCustIndustry("网络推荐");
customer.setCustAddress("北上广");
customerDao.save(customer);
}
/**
* 删除测试
* 根据id删除记录
* 先查询记录是否存在,如果存在就删除,不存在就报错
*/
@Test
public void test_delete(){
customerDao.delete(8l);
}
/**
* 查询所有
*/
@Test
public void test_findAll(){
List<Customer> list = customerDao.findAll();
for (Customer customer : list) {
System.out.println(customer);
}
}
/**
* 统计查询
*/
@Test
public void test_count(){
long count = customerDao.count();
System.out.println(count);
}
/**
* 判断指定id的客户是否存在,如果存在返回true,不存在返回false
*/
@Test
public void test_exists(){
boolean exists = customerDao.exists(4l);
System.out.println(exists);
}
}
4_v2_jqpl简单使用:
- @Query(nativeQuery=, value="")
- nativeQuery=true sql查询
- nativeQuery=false jqpl查询
- value="" 查询语句
4_v2_v1_Dao层
public interface CustomerDao extends JpaRepository<Customer, Long> , JpaSpecificationExecutor<Customer>{
/**
* jpql查询
* 根据名称查询客户信息
* @Query
*/
@Query(value = "from Customer where custName = ?1")
public Customer findByName(String custName);
/**
* 根据名称和id查询客户信息
* 默认情况下:
* 占位符的位置要与方法参数的位置一致
* 非默认情况下:
* 要在占位符后添加索引,指定该占位符从哪个参数获取值
*/
@Query(value = "from Customer where custName = ?2 and custId = ?1")
public Customer findByNameAndId(Long id,String name);
/**
* 更新操作
* @Modifying: 当前执行的是一个更新操作
* 返回值是影响记录的行数
*/
@Query(value = "update Customer set custName = ?2 where custId = ?1")
@Modifying
public Integer updateName(Long id, String name);
/**
* 查询全部
* nativeQuery: 本地查询,默认是nativeQuery=false
* true: 使用sql语句查询
* false: 使用jpql 语句查询
*/
@Query(nativeQuery = true, value = "select * from t_cst_customer")
public List<Object[]> findAllBySql();
/**
* sql 模糊查询
*/
@Query(nativeQuery = true, value = "select * from t_cst_customer where cust_name like ?1")
public List<Object[]> findAllByLike(String name);
}
4_v2_v2_测试类
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath*:applicationContext.xml")
public class JpqlTest {
@Autowired
private CustomerDao customerDao;
/**
* 根据名称查询客户
*/
@Test
public void test_findByName(){
Customer customer = customerDao.findByName("666");
System.out.println(customer);
}
/**
* 根据名称和id查询客户
*/
@Test
public void test_findByNameAndId(){
//Customer customer = customerDao.findByNameAndId("777", 4l);
Customer customer = customerDao.findByNameAndId(4l,"777");
System.out.println(customer);
}
/**
* 根据id更新名称
* @Transactional: 更新/删除操作
* 需要手动添加事务支持
* @Rollback: 默认事务自动回滚
* true|false
*/
@Test
@Transactional //添加事务支持
@Rollback(value = false)
public void test_updateName(){
Integer lin = customerDao.updateName(8l, "777");
System.out.println(lin);
}
/**
* sql 查询全部
*/
@Test
public void test_findAllBySql(){
List<Object[]> allBySql = customerDao.findAllBySql();
for (Object[] objects : allBySql) {
System.out.println(Arrays.toString(objects));
}
}
/**
* sql 模糊查询全部
*/
@Test
public void test_findAllByLike(){
List<Object[]> allBySql = customerDao.findAllByLike("%三%");
for (Object[] objects : allBySql) {
System.out.println(Arrays.toString(objects));
}
}
}
4_v3_命名规则查询
- 精准查询: findBy+实体属性名称
eg: findByCustName====> from 实体类名 where custName = ? - 模糊查询… : find+实体属性名称+查询方式(like|isNUll)
eg: findByCustNameLike====> from 实体类名 where custName like ? - 多条件查询: find + 实体属性名称 + 查询方式 + 连接符号(And|Or) 实体属性名称 + 查询方式…
eg: findByCustNameLikeAndCustIndustry ==> from 实体类名 where custName like ? and custIndustry = ?
4_v3_v1_Dao层
public interface CustomerDao extends JpaRepository<Customer, Long> , JpaSpecificationExecutor<Customer>{
/**
* 命名规则查询
* findBy实体属性名称: 查询 属性名称首字母大写
* 属性名称会被当作条件
* eg: findByCustName ===> from Customer where custName = ?
*
* findBy + 实体属性名称 精准查询
* findBy + 实体属性名称 + 查询方式(like | is noll)
* 多条件查询: 方法参数顺序要一致
* findBy + 实体属性名称 + 查询方式 + 条件连接符(And|Or) + 实体属性名称 + 查询方式...
*/
public Customer findByCustName(String custName);
/**
* 命名规则模糊查询
*/
public List<Customer> findByCustNameLike(String custName);
/**
* 命名规则多条件查询
*/
public List<Customer> findByCustNameLikeAndCustIndustry(String custName, String custIndustry);
}
4_v3_v2_测试类
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath*:applicationContext.xml")
public class JpqlTest {
@Autowired
private CustomerDao customerDao;
/**
* 命名规则查询
* 条件查询
*/
@Test
public void test_nameing(){
Customer customer = customerDao.findByName("张三1");
System.out.println(customer);
}
/**
* 命名规则模糊查询
*
*/
@Test
public void test_like(){
List<Customer> list = customerDao.findByCustNameLike("%三%");
for (Customer customer : list) {
System.out.println(customer);
}
}
/**
* 命名规则多条件查询
*
*/
@Test
public void test_ManyConditions(){
List<Customer> list = customerDao.findByCustNameLikeAndCustIndustry("%三%","网络推荐");
for (Customer customer : list) {
System.out.println(customer);
}
}
}