基本思路

1、定义返回代码的枚举类。
2、定义一个公共方法控制器 BaseRestController ，实现 success / error 系列的方法，便于自定义 Exception 类和业务控制器中调用。
3、捕获全局异常，可以自定义业务异常类，在方法中调用公共方法控制器 BaseRestController 中的 error 方法返回返回代码枚举类中的元素。

文件目录结构

环境
image.png

1、定义返回码类

将返回码类分为枚举类和常规类，好处是自由度较高，可以随喜好选择不同的返回方式

1.1、枚举类

ResponseCodeEnum

  1. package com.example.boot.response;
  3. import lombok.AllArgsConstructor;
  4. import lombok.Getter;
  6. @Getter
  7. @AllArgsConstructor
  8. public enum ResponseCodeEnum {
  10.     /**
  11.      * 通用
  12.      */
  13.     SUCCESS(1, "ok"),
  15.     ERROR(0, "error"),
  17.     /**
  18.      * 系统错误
  19.      */
  20.     InternalError(50000, "系统内部错误"),
  22.     /**
  23.      * 客户端错误
  24.      */
  25.     ClientError(30000, "客户端错误"),
  27.     /**
  28.      * 其他错误
  29.      */
  30.     OtherError(30000, "其他错误"),
  32.     ;
  34.     private Integer code;
  35.     private String msg;
  37. }

1.2、常规类

ResponseCode

  1. package com.example.boot.response;
  3. public class ResponseCode {
  5.     /**
  6.      * 成功
  7.      */
  8.     public static int SUCCESSED = 1;
  9.     /**
  10.      * 失败
  11.      */
  12.     public static int FAILED = 0;
  14.     /**
  15.      * 缺少请求参数异常
  16.      */
  17.     public static int missingServletRequestParameterException = 50000;
  18.     /**
  19.      * 参数类型不匹配错误
  20.      */
  21.     public static int methodArgumentTypeMismatchException = 50100;
  22. }

2、定义返回体类

SpringBoot 会将对象封装成 json 返回出去。所以，我们需要定义一个用来封装返回体的对象。例如：code/msg/data 等

  1. {
  2.     "code": 0,
  3.     "msg": "error",
  4.     "data": null
  5. }

Response

  1. package com.example.boot.response;
  3. import com.fasterxml.jackson.annotation.JsonProperty;
  4. import com.fasterxml.jackson.annotation.JsonPropertyOrder;
  5. import lombok.AllArgsConstructor;
  6. import lombok.Data;
  7. import lombok.NoArgsConstructor;
  8. import lombok.ToString;
  10. import java.io.Serializable;
  12. @Data
  13. @AllArgsConstructor
  14. @NoArgsConstructor
  15. @ToString
  16. @JsonPropertyOrder(value = {"code", "msg", "data"})
  17. public class Response<T> implements Serializable {
  19.     /**
  20.      * 响应码
  21.      */
  22.     @JsonProperty("code")
  23.     private Integer code;
  25.     /**
  26.      * 返回消息
  27.      */
  28.     @JsonProperty("msg")
  29.     private String msg;
  31.     /**
  32.      * 返回结果集
  33.      */
  34.     @JsonProperty("data")
  35.     private T data;
  36. }

3、定义控制器

3.1、定义公共方法控制器

BaseRestController

  1. package com.example.boot.controller;
  3. import com.example.boot.response.Response;
  4. import com.example.boot.response.ResponseCode;
  5. import com.example.boot.response.ResponseCodeEnum;
  6. import lombok.extern.slf4j.Slf4j;
  7. import org.springframework.web.bind.annotation.RestController;
  9. @RestController
  10. @Slf4j
  12. public class BaseRestController {
  14.     public BaseRestController() {
  15.         log.info("BaseRestController 构造函数被调用了");
  16.     }
  18.     /**
  19.      * success 系列方法
  20.      */
  21.     public Response success() {
  22.         Response response = new Response<>();
  24.         response.setCode(ResponseCode.SUCCESSED);
  25.         response.setData(null);
  26.         response.setMsg("ok");
  28.         return response;
  29.     }
  31.     public Response success(String msg) {
  32.         Response response = new Response<>();
  34.         response.setCode(ResponseCode.SUCCESSED);
  35.         response.setData(null);
  36.         response.setMsg(msg);
  38.         return response;
  39.     }
  41.     public Response success(String msg, Object data) {
  42.         Response response = new Response<>();
  44.         response.setCode(ResponseCode.SUCCESSED);
  45.         response.setData(data);
  46.         response.setMsg(msg);
  48.         return response;
  49.     }
  51.     public Response success(String msg, Integer code) {
  52.         Response response = new Response<>();
  54.         response.setCode(code);
  55.         response.setData(null);
  56.         response.setMsg(msg);
  58.         return response;
  59.     }
  61.     public Response success(String msg, Object data, Integer code) {
  62.         Response response = new Response<>();
  64.         response.setCode(code);
  65.         response.setData(data);
  66.         response.setMsg(msg);
  68.         return response;
  69.     }
  71.     public Response success(ResponseCodeEnum responseCodeEnum, Object data) {
  72.         Response response = new Response<>();
  74.         response.setCode(responseCodeEnum.getCode());
  75.         response.setMsg(responseCodeEnum.getMsg());
  76.         response.setData(data);
  78.         return response;
  79.     }
  81.     public Response success(ResponseCodeEnum responseCodeEnum) {
  82.         Response response = new Response<>();
  84.         response.setCode(responseCodeEnum.getCode());
  85.         response.setMsg(responseCodeEnum.getMsg());
  86.         response.setData(null);
  88.         return response;
  89.     }
  92.     /**
  93.      * error 系列方法
  94.      */
  95.     public Response error() {
  96.         Response response = new Response<>();
  98.         response.setCode(ResponseCode.FAILED);
  99.         response.setData(null);
  100.         response.setMsg("ok");
  102.         return response;
  103.     }
  105.     public Response error(String msg) {
  106.         Response response = new Response<>();
  108.         response.setCode(ResponseCode.FAILED);
  109.         response.setData(null);
  110.         response.setMsg(msg);
  112.         return response;
  113.     }
  115.     public Response error(String msg, Object data) {
  116.         Response response = new Response<>();
  118.         response.setCode(ResponseCode.FAILED);
  119.         response.setData(data);
  120.         response.setMsg(msg);
  122.         return response;
  123.     }
  125.     public Response error(String msg, Integer code) {
  126.         Response response = new Response<>();
  128.         response.setCode(code);
  129.         response.setData(null);
  130.         response.setMsg(msg);
  132.         return response;
  133.     }
  135.     public Response error(String msg, Object data, Integer code) {
  136.         Response response = new Response<>();
  138.         response.setCode(code);
  139.         response.setData(data);
  140.         response.setMsg(msg);
  142.         return response;
  143.     }
  145.     public Response error(ResponseCodeEnum responseCodeEnum, Object data) {
  146.         Response response = new Response<>();
  148.         response.setCode(responseCodeEnum.getCode());
  149.         response.setMsg(responseCodeEnum.getMsg());
  150.         response.setData(data);
  152.         return response;
  153.     }
  155.     public Response error(ResponseCodeEnum responseCodeEnum) {
  156.         Response response = new Response<>();
  158.         response.setCode(responseCodeEnum.getCode());
  159.         response.setMsg(responseCodeEnum.getMsg());
  160.         response.setData(null);
  162.         return response;
  163.     }
  165. }

3.2、定义业务控制器

IndexController

  1. package com.example.boot.controller;
  3. import com.example.boot.response.Response;
  4. import com.example.boot.response.ResponseCodeEnum;
  5. import lombok.extern.slf4j.Slf4j;
  6. import org.springframework.web.bind.annotation.RequestMapping;
  7. import org.springframework.web.bind.annotation.RequestParam;
  8. import org.springframework.web.bind.annotation.RestController;
  10. @RestController
  11. @Slf4j
  12. public class IndexController extends BaseRestController {
  13.     public IndexController() {
  14.         log.info("IndexController 构造函数被调用了");
  15.     }
  17.     @RequestMapping(path = {
  18.             "/",
  19.             "/index"
  20.     })
  21.     public Response index() {
  22.         return success();
  23.     }
  25.     @RequestMapping(path = {
  26.             "/test"
  27.     })
  28.     public Response test(@RequestParam(name = "a") Integer a) {
  29.         if (a.equals(0)) {
  30. //            return error("a不能为0");
  31. //            throw new CustomerException(201, "自定义错误");
  32.             return error(ResponseCodeEnum.ArithmeticException);
  33.         }
  35.         int b = 10 / a;
  37.         return success();
  38.     }
  39. }

在 test 方法里，我注释掉了两行代码。

1）因为在公共方法控制器 BaseRestController 中，我已经默认实现了success / error 系列的方法，所以在业务 controller 中可以这样返回 msg：

  1. return error("a不能为0");

2）因为捕获了全局异常，所以可以在业务 controller 中直接 throw 我们自定义的异常类。

  1. throw new CustomerException(201, "自定义错误");

不过我还是比较推荐使用返回码枚举类的方式来返回错误信息：

  1. return error(ResponseCodeEnum.ArithmeticException);

4、定义异常类

4.1、定义一个处理全局异常的类。

GlobalExceptionHandler

  1. package com.example.boot.exception;
  3. import com.example.boot.controller.BaseRestController;
  4. import com.example.boot.response.Response;
  5. import com.example.boot.response.ResponseCode;
  6. import lombok.extern.slf4j.Slf4j;
  7. import org.springframework.web.bind.annotation.ExceptionHandler;
  8. import org.springframework.web.bind.annotation.RestControllerAdvice;
  10. import javax.servlet.http.HttpServletRequest;
  11. import java.util.HashMap;
  12. import java.util.Map;
  14. @RestControllerAdvice
  15. @Slf4j
  16. public class GlobalExceptionHandler extends BaseRestController {
  18.     /**
  19.      * 处理所有类型的异常
  20.      */
  21.     @ExceptionHandler({
  22.             Exception.class,
  23.     })
  24.     public Response exceptionHandler(HttpServletRequest req, Exception e) {
  25.         log.error("全局异常捕获：", e);
  27.         Map<String, Object> detail = new HashMap<>();
  28.         detail.put("exception", e.toString());
  30.         return error("全局异常捕获", detail, ResponseCode.FAILED);
  31.     }
  33.     /**
  34.      * 处理自定义的业务异常
  35.      */
  36.     @ExceptionHandler(value = CustomerException.class)
  37.     public Response customerExceptionHandler(HttpServletRequest req, Exception e) {
  38.         log.error("自定义业务异常：", e);
  40.         Map<String, Object> detail = new HashMap<>();
  41.         detail.put("exception", e.toString());
  43.         return error("自定义异常", detail, ResponseCode.FAILED);
  44.     }
  45. }

4.2、定义业务异常类

根据业务需求，定义自己需要的异常类。

CustomerException

  1. package com.example.boot.exception;
  4. import lombok.AllArgsConstructor;
  5. import lombok.Data;
  6. import lombok.NoArgsConstructor;
  8. @Data
  9. @AllArgsConstructor
  10. @NoArgsConstructor
  11. public class CustomerException extends RuntimeException {
  12.     /**
  13.      * 错误码
  14.      */
  15.     protected Integer errorCode;
  16.     /**
  17.      * 错误信息
  18.      */
  19.     protected String errorMsg;
  20. }

5、测试

5.1、正常请求

image.png

5.2、业务exception

image.png

5.3、全局异常捕获

image.png