上次我们讲述了《Spring-Data-Jpa概述与接口》，接下来我们再讲讲Spring-Data-Jpa环境配置与实际应用。
Spring-Data 方法定义规范与使用配置
简单条件查询: 查询某一个实体类或者集合
按照 Spring Data 的规范，查询方法以 find | read | get 开头,涉及条件查询时，条件的属性用条件关键字连接，要注意的是：条件属性以首字母大写。
例如：定义一个 Entity 实体类：
class User｛
private String firstName;
private String lastName;
｝
使用And条件连接时，应这样写：
findByLastNameAndFirstName(String lastName,String firstName);条件的属性名称与个数要与参数的位置与个数一一对应
直接在接口中定义查询方法，如果是符合规范的，可以不用写实现，目前支持的关键字写法如下：
@Query注解
这种查询可以声明在 Repository 方法中，摆脱像命名查询那样的约束，将查询直接在相应的接口方法中声明，结构更为清晰，这是 Spring data 的特有实现。
@Query来指定本地查询
自定义 Repository 方法
定义一个接口: 声明要添加的, 并自实现的方法
提供该接口的实现类: 类名需在要声明的 Repository 后添加 Impl, 并实现方法
声明 Repository 接口, 并继承 1) 声明的接口
使用.
注意: 默认情况下, Spring Data 会在 base-package 中查找 "接口名Impl" 作为实现类. 也可以通过 repository-impl-postfix 声明后缀.
环境配置与实际应用
pom.xml 文件坐标配置
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<slf4j.version>1.7.0</slf4j.version>
<junit.version>4.12</junit.version>
<spring.version>4.3.2.RELEASE</spring.version>
<hibernate.version>4.3.11.Final</hibernate.version>
</properties> <dependencies>
<!-- slf4j -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency> <!-- junit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency> <!-- 数据库依赖 -->
<!-- mysql数据库驱动 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.21</version>
</dependency>
<dependency>
<groupId>c3p0</groupId>
<artifactId>c3p0</artifactId>
<version>0.9.1.2</version>
</dependency>
<!-- spring3 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</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-jdbc</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-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-expression</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- springdatajpa -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-commons</artifactId>
<version>1.7.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.5.1.RELEASE</version>
</dependency> <!-- aspectjweaver -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.7.0</version>
</dependency> <!-- hibernate4 -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency> <dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>asm</groupId>
<artifactId>asm</artifactId>
<version>3.3.1</version>
</dependency>
</dependencies> jdbc.properties 文件 jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/jpa?useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=root 上海尚学堂java
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<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- 配置自动扫描的包 -->
<context:component-scan base-package="com.shsxt"></context:component-scan> <!-- 1. 配置数据源 -->
<context:property-placeholder location="classpath:db.properties"/> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"></property>
<property name="jdbcUrl" value="${jdbc.url}"></property>
<property name="user" value="${jdbc.username}"></property>
<property name="password" value="${jdbc.password}"></property>
</bean>
<!-- 2. 配置 JPA 的 EntityManagerFactory -->
<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.shsxt.entity"></property>
<property name="jpaProperties">
<props>
<!-- 生成的数据表的列的映射策略 -->
<prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
<!-- hibernate 基本属性 -->
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.format_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
</bean>
<!-- 3. 配置事务管理器 -->
<bean id="transactionManager"
class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"></property>
</bean>
<!-- 4. 配置支持注解的事务 -->
<tx:annotation-driven transaction-manager="transactionManager"/> <!-- 5. 配置 SpringData -->
<!-- 加入 jpa 的命名空间 -->
<!-- base-package: 扫描 Repository Bean 所在的 package -->
<jpa:repositories base-package="com.shsxt.dao"
entity-manager-factory-ref="entityManagerFactory" repository-impl-postfix="Impl" ></jpa:repositories>
</beans>
Dao 接口实例代码
package com.shsxt.dao; import com.shsxt.entity.User;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param; import java.util.List; /**
* Created by lp on 2017/12/21.
*/
public interface UserRepository extends UserDao,JpaRepository<User,Integer> {
/*
命名查询约束定义
*/
// 根据属性字段精确查询
public List<User> findByUserName(String userName);
// 根据属性字段模糊匹配
public List<User> findByUserNameLike(String userName);
// 多条件匹配
public List<User> findByUserNameAndUserPwd(String userName,String userPwd); // 返回分页对象 页码 每页大小 根据用户名模糊匹配用户记录 页码 每页大小设置
public Page<User> findByUserNameLike(String userName, Pageable pageable); // 返回分页列表数据
public List<User> findByUserPwdLike(String userPwd, Pageable pageable); /*
query查询
参数传递01:占位符 上海尚学堂java
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*/
@Query("select u from User u where u.userName like %?1%")
public List<User> UserByUserName(String userName); @Query("select u from User u where u.userName=?1 and u.userPwd=?2")
public List<User> loadUserByUserNameAndUserPwd(String userName,String userPwd); /**
*参数传递02:命名参数
* @param userName
* @param userPwd
* @return
*/
@Query("select u from User u where u.userName like :userName and u.userPwd =:userPwd")
public List<User> loadUserByUserNameAndUserPwd02(@Param("userName") String userName,@Param("userPwd") String userPwd); /**
* 占位符添加模糊匹配标志
*/
@Query("select u from User u where u.userName like %:userName%")
public List<User> loadUserByUserName02(@Param("userName") String userName,Pageable pageable); /**
* 本地sql 查询支持
*/
@Query(value = "select * from t_user u where u.user_name like %?1%",nativeQuery = true)
public List<User> loadUserByUserName03(String userName); }