SpringData JPA的学习笔记之环境搭建

一、环境搭建

1、加入jar包

spring jar+jpa jar +springData jar>>SpringData jar包 2、配置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: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-1.3.xsd
 http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
 http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 配置自动扫描的包 -->
 <context:component-scan base-package="com.atguigu.springdata"></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="user" value="${jdbc.user}"></property>
 <property name="password" value="${jdbc.password}"></property>
 <property name="driverClass" value="${jdbc.driverClass}"></property>
 <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property> <!-- 配置其他属性 -->
 </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.atguigu.springdata"></property>
 <property name="jpaProperties">
 <props>
 <!-- 二级缓存相关 -->
 <!--
 <prop key="hibernate.cache.region.factory_class">org.hibernate.cache.ehcache.EhCacheRegionFactory</prop>
 <prop key="net.sf.ehcache.configurationResourceName">ehcache-hibernate.xml</prop>
 -->
 <!-- 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.atguigu.springdata"
 entity-manager-factory-ref="entityManagerFactory"></jpa:repositories> </beans>

//db.properties

 jdbc.user=root
 jdbc.password=123456
 jdbc.jdbcUrl=jdbc:mysql:///jpa
 jdbc.driverClass=com.mysql.jdbc.Driver

3、创建实体类Person

package com.atguigu.springdata;import java.util.Date;import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
@Table(name="t_person")
@Entity
public class Person {private Integer id;
private String lastname;
private String email;
private Date birthday;
@GeneratedValue
@Id
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLastname() {
return lastname;
}
public void setLastname(String lastname) {
this.lastname = lastname;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
@Override
public String toString() {
return "Person [id=" + id + ", lastname=" + lastname + ", email=" + email + ", birthday=" + birthday + "]";
}}

4、继承Repository接口Repository<Class<T>clazz,Object obj>,其中Class<T>clazz是实体类，obj是主键类型

package com.atguigu.springdata.dao;import org.springframework.data.repository.Repository;import com.atguigu.springdata.Person;public interface PersonRespository extends Repository<Person,Integer>{Person getByLastname(String lastname);}

>>Repository接口说明：

Repository 接口是 Spring Data 的一个核心接口，它不提供任何方法，开发者需要在自己定义的接口中声明需要的方法
public interface Repository<T, ID extends Serializable> { }
Spring Data可以让我们只定义接口，只要遵循 Spring Data的规范，就无需写实现类。
与继承 Repository 等价的一种方式，就是在持久层接口上使用 @RepositoryDefinition 注解，并为其指定 domainClass 和 idClass 属性。如下两种方式是完全等价的

 package com.atguigu.springdata.dao; import org.springframework.data.repository.RepositoryDefinition; import com.atguigu.springdata.Person; @RepositoryDefinition(domainClass=Person.class,idClass=Integer.class)
 public interface PersonRepository2 {
 Person getByLastname(String lastname);
 }

>>Repository的子接口基础的 Repository 提供了最基本的数据访问功能，其几个子接口则扩展了一些功能。它们的继承关系如下：