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