SpringData 第二章：继承PagingAndSortingRepository进行分页开发

一、pom.xml配置

<!--Mysql 驱动包 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.38</version></dependency><!-- https://mvnrepository.com/artifact/org.springframework.data/spring-data-jpa --><dependency><groupId>org.springframework.data</groupId><artifactId>spring-data-jpa</artifactId><version>1.11.6.RELEASE</version></dependency><!-- https://mvnrepository.com/artifact/org.hibernate/hibernate-entitymanager --><dependency><groupId>org.hibernate</groupId><artifactId>hibernate-entitymanager</artifactId><version>5.2.9.Final</version></dependency><!-- 添加阿里巴巴数据源支持 --><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.0.12</version></dependency>

二、SpringData.xml配置

<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">                <!-- 扫描包 --><context:component-scan base-package="com.mingde" /> <!-- 定义数据源(阿里巴巴得鲁伊) com.alibaba.druid.pool.DruidDataSource"  --><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" ><property name="driverClassName" value="com.mysql.jdbc.Driver" /><property name="url" value="jdbc:mysql:///SpringData" /><property name="username" value="root" /><property name="password" value="123" /></bean><!-- 配置实体管理工厂   定义entityManagerFactory --><bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" ><!-- 加载数据源 --><property name="dataSource" ref="dataSource" /><!-- 配置提供商实现适配器 --><property name="jpaVendorAdapter"><bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" /></property><!--  定义实体扫描器   --><property name="packagesToScan" value="com.mingde" /><!-- 定义一系列的JPA属性 --><property name="jpaProperties"><props><prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop><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><!-- 定义是我管理器 --><bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"><property name="entityManagerFactory" ref="entityManagerFactory" ></property></bean><!-- 定义注解事务驱动 --><tx:annotation-driven transaction-manager="transactionManager" /><!-- 定义jpa：repositories --><jpa:repositories base-package="com.mingde" entity-manager-factory-ref="entityManagerFactory"></jpa:repositories></beans>

三、实体类

package com.mingde.po;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;@Entitypublic class Student {@Id@GeneratedValue(strategy=GenerationType.IDENTITY)private int sid;private String sname;private String sex;private int age;private String addr;

四、Dao层定义

package com.mingde.dao;import org.springframework.data.repository.PagingAndSortingRepository;import com.mingde.po.Student;

//继承该接口即可，若有自定义的方法就写上去//继承该接口，可以使用该接口里面内定的方法，可及继承该接口的父接口CrudRepository，一般用这个子接口，因为子接口拥有父类的所有非私有的方法public interface StudentDao extends PagingAndSortingRepository<Student, Integer> {//这里可以写自定义的方法，因为该接口没有修改的方法，所以需要自己手动写

@Modifying@Query("update Student st set st.sname=:sname,st.saddr=:saddr where st.sid=:sid")public void update(@Param("sname")String sname,   @Param("saddr")String saddr,   @Param("sid")int sid) throws Exception;}

PagingAndSortingRepository接口的2个方法

PagingAndSortingRepository接口继承CrudRepository接口

CrudRepository接口中的方法

所以继承接口PagingAndSortingRepository就可以用以上全部的方法

五、Service层定义

package com.mingde.servier;import java.util.List;import javax.annotation.Resource;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.domain.Page;import org.springframework.data.domain.Pageable;import org.springframework.stereotype.Service;import com.mingde.dao.StudentDao;import com.mingde.po.Student;@Servicepublic class StudentServier  {@Resource(name="studentDao")StudentDao sd;@Autowiredprivate StudentDao studentDao;//分页查询public Page<Student> findAll(Pageable pageable) throws Exception{return studentDao.findAll(pageable);}//查询所有学生信息public List<Student> findAll()throws Exception{return (List<Student>) sd.findAll();}//根据id编号查询学生信息public Student findOne(int id)throws Exception{return sd.findOne(id);}//添加学生信息public void save(Student st)throws Exception{sd.save(st);}//根据id删除学生信息public void delete(int id)throws Exception{sd.delete(id);}//根据id判断该学生是否存在public boolean exists(int id)throws Exception{return sd.exists(id);}}

六、测试类

package com.mingde.test;import java.util.List;import org.junit.Before;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import org.springframework.data.domain.Page;import org.springframework.data.domain.PageRequest;import org.springframework.data.domain.Pageable;import com.mingde.po.Student;import com.mingde.servier.StudentServier;public class StudentTest {private ApplicationContext ac;private StudentServier ss;@Beforepublic void tearDown() throws Exception {ac=new ClassPathXmlApplicationContext("SpringData.xml");ss=ac.getBean(StudentServier.class);}@Testpublic void test() throws Exception {/*//查询所有学生信息List<Student> findAll = ss.findAll();System.out.println(findAll);//根据学生id查询学生信息Student findOne = ss.findOne(1002);System.out.println(findOne);//添加学生信息Student st=new Student("史迪奇", "男", 10, "迪尼斯");ss.save(st);System.out.println("添加成功");//删除指定id学生信息ss.delete(1004);System.out.println("删除成功");//根据id判断该学生是否存在boolean exists = ss.exists(1003);System.out.println("该学生存在？："+exists);*/}//分页效果@Testpublic void tes2t() throws Exception {Pageable pageable = new PageRequest(1,3);Page<Student> stud = ss.findAll(pageable);//下面查看分页的一系列数据int page = stud.getNumber();System.out.println("当前页码：" + (page + 1));int records = stud.getNumberOfElements();System.out.println("当前页记录数：" + records);int size = stud.getSize();System.out.println("每一页的记录数：" + size);long totalRecords = stud.getTotalElements();System.out.println("总记录数：" + totalRecords);int totalPages = stud.getTotalPages();System.out.println("总页数：" + totalPages);List<Student> list = stud.getContent();System.out.println("当前页的数据：" + list);}}