6.SpringBoot 传统方式统一数据格式返回-一一网

一、前言

前后端分离是当今服务形式的主流，如何设计一个好的 RESTful API ，以及如何让前端小伙伴可以处理标准的 response JSON 数据结构都至关重要，为了让前端有更好的逻辑展示与页面交互处理，每一次 RESTful 请求都应该包含以下几个信息:

名称	描述
status	状态码，标识请求成功与否，http状态保持一致
msg	错误消息，与错误码相对应，更具体的描述异常信息
exception	异常信息，给出详细的异常栈信息
data	返回结果，通常是 Bean 对象对应的 JSON 数据, 通常为了应对不同返回值类型，将其声明为泛型类型

二、实现

1.依赖

<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.projectlombok</groupId>
	<artifactId>lombok</artifactId>
</dependency>

<dependency>
	<groupId>cn.hutool</groupId>
	<artifactId>hutool-all</artifactId>
</dependency>

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-test</artifactId>
	<scope>test</scope>
</dependency>
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2.定义通用返回类

import java.io.Serializable;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.ToString;

@Getter
@ToString
@Builder
@EqualsAndHashCode(callSuper = false)
@AllArgsConstructor
@NoArgsConstructor
public class ApiResponses<T> implements Serializable{

	private static final long serialVersionUID = -6548932393957418417L;

	@Builder.Default
	private int status = 200;

	private String code;

	private String msg;
	
	private String exception;

	private T data;
}
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3.控制器

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.gitee.example.model.User;
import com.gitee.web.api.ApiResponses;

/**
 * 接口类
 */
@RestController
@RequestMapping(value = "/users2")
public class UserController2 {

	// 创建线程安全的Map
	private static Map<Long, User> users = Collections.synchronizedMap(new HashMap<Long, User>());

	@GetMapping
	public ApiResponses<List<User>> getUserList() {
		// 处理"/users/"的GET请求，用来获取用户列表
		// 还可以通过@RequestParam从页面中传递参数来进行查询条件或者翻页信息的传递
		List<User> r = new ArrayList<>(users.values());
		return ApiResponses.<List<User>>builder().data(r).msg("查询列表成功").build();
	}
 
	@PostMapping
	public ApiResponses<String> postUser(@RequestBody User user) {
		// 处理"/users/"的POST请求，用来创建User
		// 除了@RequestBody绑定参数之外，还可以通过@RequestParam从页面中传递参数
		users.put(user.getId(), user);
		return ApiResponses.<String>builder().msg("新增成功").build();
	}

	@GetMapping("/{id}")
	public ApiResponses<User> getUser(@PathVariable Long id) {
		// 处理"/users/{id}"的GET请求，用来获取url中id值的User信息
		// url中的id可通过@PathVariable绑定到函数的参数中
		return  ApiResponses.<User>builder().data(users.get(id)).msg("查询成功").build();
	}

	@PutMapping("/{id}")
	public ApiResponses<String> putUser(@PathVariable Long id, @RequestBody User user) {
		// 处理"/users/{id}"的PUT请求，用来更新User信息
		User u = users.get(id);
		u.setName(user.getName());
		u.setAge(user.getAge());
		users.put(id, u);
		return ApiResponses.<String>builder().msg("更新成功").build();
	}

	@DeleteMapping("/{id}")
	public ApiResponses<String> deleteUser(@PathVariable Long id) {
		// 处理"/users/{id}"的DELETE请求，用来删除User
		users.remove(id);
		return ApiResponses.<String>builder().msg("删除成功").build();
	}

}
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4.Mock测试

import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import java.nio.charset.StandardCharsets;
import java.util.List;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.RequestBuilder;

import com.gitee.example.model.User;
import com.gitee.web.api.ApiResponses;

import cn.hutool.core.lang.TypeReference;
import cn.hutool.json.JSONUtil;

@AutoConfigureMockMvc
@RunWith(SpringRunner.class)
@SpringBootTest(classes = Application.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class ApplicationTests2 {
   
	@Autowired
    private MockMvc mvc;

 
	@Test
    public void testUserController2() throws Exception {
        // 测试UserController
        RequestBuilder request;

        // 1、get查一下user列表，应该为空
        request = get("/users2/");
        MvcResult result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        String content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<List<User>> response = JSONUtil.toBean(content, new TypeReference<ApiResponses<List<User>>>() {}, true);
        assertThat(response.getData().size(), is(0));
        assertThat(response.getMsg(), is("查询列表成功"));

        // 2、post提交一个user
        User puser = new User();
        puser.setId(1L);
        puser.setName("测试大师");
        puser.setAge(20);
        
        request =  post("/users2/")
        .contentType(MediaType.APPLICATION_JSON)
        .content(JSONUtil.toJsonStr(puser));
        
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<String> response1 = JSONUtil.toBean(content, new TypeReference<ApiResponses<String>>() {}, true);
        assertThat(response1.getMsg(), is("新增成功"));

        // 3、get获取user列表，应该有刚才插入的数据
        request = get("/users2/");
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<List<User>> response2 = JSONUtil.toBean(content, new TypeReference<ApiResponses<List<User>>>() {}, true);
        assertThat(response2.getData().size(), is(1));
        assertThat(response2.getMsg(), is("查询列表成功"));

        // 4、put修改id为1的user
        puser.setName("测试终极大师");
        puser.setAge(30);
        request =  put("/users2/1")
                .contentType(MediaType.APPLICATION_JSON)
                .content(JSONUtil.toJsonStr(puser));
        
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<String> response3 = JSONUtil.toBean(content, new TypeReference<ApiResponses<String>>() {}, true);
        assertThat(response3.getMsg(), is("更新成功"));

        // 5、get一个id为1的user
        request = get("/users2/1");
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<User> response4 = JSONUtil.toBean(content, new TypeReference<ApiResponses<User>>() {},true);
        User user = response4.getData();
        assertThat(user.getId(), is(1L));
        assertThat(user.getName(), is("测试终极大师"));

        // 6、del删除id为1的user
        request = delete("/users2/1");
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<String> response5 = JSONUtil.toBean(content, new TypeReference<ApiResponses<String>>() {}, true);
        assertThat(response5.getMsg(), is("删除成功"));

        // 7、get查一下user列表，应该为空
        request = get("/users2/");
        result = mvc.perform(request)
                .andExpect(status().isOk())
                .andReturn();
        content = result.getResponse().getContentAsString(StandardCharsets.UTF_8);
        ApiResponses<List<User>> response6 = JSONUtil.toBean(content, new TypeReference<ApiResponses<List<User>>>() {}, true);
        assertThat(response6.getData().size(), is(0));
        assertThat(response6.getMsg(), is("查询列表成功"));
    }

}
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