关于spring-data-jpa的排序问题

本测试基于springBoot框架实现。

pom.xml文件：

<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.xiaowu</groupId>

  <artifactId>spring-boot-test-master</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.5.1.RELEASE</version>

        <relativePath/> <!-- lookup parent from repository -->

    </parent>

    <!-- 字符集 -->

    <properties>

        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

        <java.version>1.8</java.version>

    </properties>

    <dependencies>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-test</artifactId>

            <scope>test</scope>

        </dependency>

          <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-data-jpa</artifactId>

        </dependency>

        <dependency>

          <groupId>mysql</groupId>

          <artifactId>mysql-connector-java</artifactId>

        </dependency>

    </dependencies>

    <build>

        <plugins>

            <plugin>

                <groupId>org.springframework.boot</groupId>

                <artifactId>spring-boot-maven-plugin</artifactId>

            </plugin>

        </plugins>

    </build>

</project>

配置文件application.properties

server.port=80

entitymanager.packagesToScan= com.zslin

spring.datasource.url=jdbc:mysql://localhost:3306/demo?/useUnicode=true&characterEncoding=utf-8&useSSL=true&autoReconnect=true

spring.datasource.username=root

spring.datasource.password=root

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.jpa.properties.hibernate.hbm2ddl.auto=update

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5Dialect

项目入口，启动类：

package com.zslin;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

/**

 *

 * @author Administrator

 *

 */

@SpringBootApplication

public class RootApplication {

    public static void main(String [] args) {

        SpringApplication.run(RootApplication.class, args);

    }

}

实体对象：

package com.zslin.model;

import javax.persistence.*;

/**

 *

 * @author Administrator

 *

 */

@Entity

@Table(name = "t_user")

public class User {

    @Id

    @GeneratedValue(strategy = GenerationType.AUTO)

    private Integer id;

    @Column(name = "user_name")

    private String userName;

    private String password;

    @Column(name = "nick_name")

    private String nickName;

    private String email;

    public Integer getId() {

        return id;

    }

    public void setId(Integer id) {

        this.id = id;

    }

    public String getUserName() {

        return userName;

    }

    public void setUserName(String userName) {

        this.userName = userName;

    }

    public String getPassword() {

        return password;

    }

    public void setPassword(String password) {

        this.password = password;

    }

    public String getNickName() {

        return nickName;

    }

    public void setNickName(String nickName) {

        this.nickName = nickName;

    }

    public String getEmail() {

        return email;

    }

    public void setEmail(String email) {

        this.email = email;

    }

}

service接口：

import com.zslin.model.User;

import org.springframework.data.jpa.repository.JpaRepository;

/**

 *

 * @author Administrator

 *

 */

public interface IUserService extends JpaRepository<User, Integer> {

}

封装SortDto对象

package com.zslin.tools;

/**

 *

 * @author Administrator

 *

 */

public class SortDto {

    //排序方式

    private String orderType;

    //排序字段

    private String orderField;

    public String getOrderField() {

        return orderField;

    }

    public void setOrderField(String orderField) {

        this.orderField = orderField;

    }

    public String getOrderType() {

        return orderType;

    }

    public void setOrderType(String orderType) {

        this.orderType = orderType;

    }

    public SortDto(String orderType, String orderField) {

        this.orderType = orderType;

        this.orderField = orderField;

    }

    //默认为DESC排序

    public SortDto(String orderField) {

        this.orderField = orderField;

        this.orderType = "desc";

    }

}

封装 SortTools工具类：

package com.zslin.tools;

import org.springframework.data.domain.Sort;

/**

 *

 * @author Administrator

 *

 */

public class SortTools {

    public static Sort basicSort() {

        return basicSort("desc", "id");

    }

    public static Sort basicSort(String orderType, String orderField) {

        Sort sort = new Sort(Sort.Direction.fromString(orderType), orderField);

        return sort;

    }

    public static Sort basicSort(SortDto... dtos) {

        Sort result = null;

        for(int i=0; i<dtos.length; i++) {

            SortDto dto = dtos[i];

            if(result == null) {

                result = new Sort(Sort.Direction.fromString(dto.getOrderType()), dto.getOrderField());

            } else {

                result = result.and(new Sort(Sort.Direction.fromString(dto.getOrderType()), dto.getOrderField()));

            }

        }

        return result;

    }

}

直接上测试类：

package com.zslin;

import com.zslin.model.User;

import com.zslin.service.IUserService;

import com.zslin.tools.SortDto;

import com.zslin.tools.SortTools;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.data.domain.Sort;

import org.springframework.test.context.ActiveProfiles;

import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

@RunWith(SpringRunner.class)

@SpringBootTest

@ActiveProfiles("dev")

public class UserSortTest {

    @Autowired

    private IUserService userService;

     
　　//ID 升序

    @Test

    public void testSort() {

        Sort sort = new Sort(Sort.Direction.ASC, "id");

        List<User> list = userService.findAll(sort);

        for(User u : list) {

            System.out.println(u.getUserName());

        }

    }


    //ID  降序

    @Test

    public void testSort2() {

        List<User> list = userService.findAll(SortTools.basicSort());

        for(User u : list) {

            System.out.println(u.getUserName());

        }

    }


    //用户名  倒序

    @Test

    public void testSort3() {

        List<User> list = userService.findAll(SortTools.basicSort("desc", "userName"));

        for(User u : list) {

            System.out.println(u.getId()+"===="+u.getUserName());

        }

    }

    //组合排列

    @Test

    public void testSort4() {

        List<User> list = userService.findAll(SortTools.basicSort(new SortDto("desc", "userName"), new SortDto("id")));

        for(User u : list) {

            System.out.println(u.getId()+"===="+u.getUserName());

        }

    }

}

如果没有测试数据，可以创建一个测试类进行数据的添加：

package com.zslin;

import com.zslin.model.User;

import com.zslin.service.IUserService;

import org.junit.Test;

import org.junit.runner.RunWith;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import org.springframework.test.context.junit4.SpringRunner;

/**

 *

 * @author Administrator

 *

 */

@SpringBootTest

@RunWith(SpringRunner.class)

public class UserInitTest {

    @Autowired

    private IUserService userService;

    @Test

    public void initTest() {

        for(int i=1; i<=10; i++) {

            User u = new User();

            u.setEmail("email"+i+"@domain.com");

            u.setPassword("pwd"+i);

            u.setUserName("user"+i);

            u.setNickName("nickname"+i);

            userService.save(u);

        }

    }

}

项目结构图：

示例代码(GitHub位置)：  https://github.com/xiaowu135/spring-boot-test-master.git