SpringBoot全局异常处理

　　最恶心的事莫过于，后台出现异常返回的是一坨错误码，如下图。前端的人一定很抓狂。今天我们看看Java是如何处理异常的，更友好的返回错误信息。就拿做小程序接口时的一个demo。
　　基本概念
　　当然我们是基于spring简单的使用，首先我们了解用到的几个注解：@ControllerAdvice  对Controller的一个增强，可以对异常进行统一处理 @ExceptionHandle 捕获所有控制器里面的异常开始搞起来
　　首先定义个全局的异常处理类：package com.fms.config.exception;  import com.fms.config.Constant; import com.fms.config.exception.customer.wx.WxException; import com.fms.config.exception.customer.WxJsCodeEmptyException; import com.fms.http.BaseResponseJson; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import org.springframework.web.bind.annotation.ControllerAdvice; import org.springframework.web.bind.annotation.ResponseBody;   @ControllerAdvice public class ExceptionHandler {      private static final Logger logger = LogManager.getLogger(ExceptionHandler.class);      /**      * 处理自定义的业务异常      *      * @return      */     @org.springframework.web.bind.annotation.ExceptionHandler(Exception.class)     @ResponseBody     public BaseResponseJson handerException(Exception e) {         logger.info(e);         return BaseResponseJson.fail(Constant.EX_UNKNOW_EXCEPTION, ＂未知错误＂);      }      /**      * 处理微信相关的异常      *      * @return      */     @org.springframework.web.bind.annotation.ExceptionHandler(WxException.class)     @ResponseBody     public BaseResponseJson handerWxException(WxException e) {         if (e instanceof WxJsCodeEmptyException) {//微信小程序登录时获取的 js_code 出错             return BaseResponseJson.fail(Constant.WX_JS_CODE_EMPTY, Constant.WX_JS_CODE_EMPTY_MSG);         } else {          }         logger.info(e);         return BaseResponseJson.fail(Constant.EX_UNKNOW_EXCEPTION, ＂微信API出错＂);      }     /**      * 其他业务异常      */   }
　　WxException是自定义的一个微信异常类，WxException是微信相关的异常的基类，如：WxJsCodeEmptyException 。BaseResponseJson是返回给前端的信息。package com.fms.http;   import com.fasterxml.jackson.annotation.JsonProperty; import com.fms.enum_pack.ResponseCode; import java.io.Serializable;  /**  * Java封装接口返回统一格式  */ public class BaseResponseJson implements Serializable {      private static final long serialVersionUID = -3948389268046368059L;     @JsonProperty()     private String code;     @JsonProperty()     private String msg;     @JsonProperty()     private Object data;      public static BaseResponseJson success( ) {         return resultData(ResponseCode.SUCCESS.val(), ResponseCode.SUCCESS.msg());     }     public static BaseResponseJson success(Object data) {         return resultData(ResponseCode.SUCCESS.val(), ResponseCode.SUCCESS.msg(), data);     }      public static BaseResponseJson success(Object data, String msg) {         return resultData(ResponseCode.SUCCESS.val(), msg, data);     }      public static BaseResponseJson fail(String msg) {         return resultData(ResponseCode.ERROR.val(), msg);     }     public static BaseResponseJson fail() {         return resultData(ResponseCode.ERROR.val(), ResponseCode.ERROR.msg());     }      public static BaseResponseJson fail(String code, String msg) {         return resultData(code, msg, null);     }      public static BaseResponseJson fail(String code, String msg, Object data) {         return resultData(code, msg, data);     }      private static BaseResponseJson resultData(String code, String msg, Object data) {         BaseResponseJson resultData = new BaseResponseJson();         resultData.setCode(code);         resultData.setMsg(msg);         resultData.setData(data);         return resultData;     }      private static BaseResponseJson resultData(String code, String msg) {         BaseResponseJson resultData = new BaseResponseJson();         resultData.setCode(code);         resultData.setMsg(msg);         return resultData;     }      public String getCode() {         return code;     }      public void setCode(String 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;     } } 在Controller里抛出异常   if (auth_code2SessionRequest == null || StringUtils.isEmpty(auth_code2SessionRequest.getJs_code())) {             throw new WxJsCodeEmptyException();         }返回结果：{＂code＂:＂10002＂,＂msg＂:＂微信小程序登录时获取的 js_code为空＂,＂data＂:null}最后：
　　这样就比较友好了，当然根据业务还可以继续封装。