SpringBoot 统一返回格式

一、为什么要统一返回？

二、全局异常处理代码

三、统一返回对象代码

四、使用方法

五、结果展示

一、为什么要统一返回？

在Spring Boot应用中，为了保持API接口的响应格式统一，通常会采用全局异常处理和自定义返回对象的方式

二、全局异常处理代码

package com.by.config;

import cn.hutool.json.JSONUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

@RestControllerAdvice(basePackages = {"com.by"})
@Slf4j
public class MyResponseAdvice implements ResponseBodyAdvice<Object> {

    @ExceptionHandler(Exception.class)
    public Object processException(Exception ex){
        ResponseDTO responseDto  = new ResponseDTO();
        responseDto.setCode(1);
        responseDto.setMsg(ex.getMessage());
        return  responseDto;
    }

    @Override
    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
        return true;
    }
    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request, ServerHttpResponse response) {

        if(body instanceof  ResponseDTO){
            return  body;
        }
        ResponseDTO  responseDto  = new ResponseDTO();
        responseDto.setCode(0);
        responseDto.setMsg("请求成功");
        responseDto.setData(body);

        if (selectedConverterType == StringHttpMessageConverter.class) {
            return JSONUtil.toJsonStr(responseDto);
        } else {
            return responseDto;
        }


    }
}

三、统一返回对象代码

默认0代表成功

package com.by.config;

;


public class ResponseDTO {
    private int code;  //  0,非0 错误码
    private String msg; // 如果非0的时候，显示的是错误的信息
    private Object data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    public static  ResponseDTO success(Object data)
    {
        ResponseDTO responseDTO = new ResponseDTO();
        responseDTO.setCode(0);
        responseDTO.setData(data);
        //返回成功
        return responseDTO;
    }
    public static ResponseDTO error(int code,String msg)
    {
        ResponseDTO responseDTO = new ResponseDTO();
        responseDTO.setCode(code);
        responseDTO.setMsg(msg);
        return responseDTO;
    }
}