Rest接口中，异常处理更通用。

系统管理员 2022-05-21 23:35 149阅读 0赞

**Java程序中，异常处理对于程序来说是非常基础。但是真正能很好理解并且很好的统一处理，这样会使得代码逻辑更清晰，更高效。下面就是程序中需要处理并且注意的异常统一处理案例：**

**通用异常处理类：**

package com.jd.ccc.sys.biz.yb.mall.common.exception;
    
    import com.jd.ccc.sys.biz.yb.mall.common.enums.CodeEnum;
    import lombok.ToString;
    
    /**
     * 商城通用异常
     * 
     * @create 2018-4-28
     * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
     *
     */
    @ToString
    public class YbMallException extends RuntimeException {
    
       private static final long serialVersionUID = 111820440373615072L;
    
       /**
        * 异常代码
        */
       private int code;
       /**
        * 异常消息
        */
       private String message;
    
       public YbMallException(CodeEnum codeEnum) {
          this.code = codeEnum.getCode();
          this.message = codeEnum.getMessage();
       }
    
       public YbMallException(int code, String message) {
          super(message);
          this.code = code;
          this.message = message;
       }
    
       public YbMallException(int code, String message, Throwable cause) {
          super(message, cause);
          this.code = code;
          this.message = message;
       }
    
       public int getCode() {
          return code;
       }
    
       public void setCode(int code) {
          this.code = code;
       }
    
       public String getMessage() {
          return message;
       }
    
       public void setMessage(String message) {
          this.message = message;
       }
    
    }
    服务层异常处理类：

package com.jd.ccc.sys.biz.yb.mall.common.exception;
    
    import com.jd.ccc.sys.biz.yb.mall.common.enums.CodeEnum;
    
    import lombok.ToString;
    /**
     * 商城服务层异常
     * 
     * @create 2018-4-28
     * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
     *
     */
    @ToString
    public class YbMallServiceException extends YbMallException {
    
       private static final long serialVersionUID = -3140415845720194815L;
    
       public YbMallServiceException(CodeEnum codeEnum) {
          super(codeEnum);
       }
    
       public YbMallServiceException(int code, String message) {
          super(code, message);
       }
    
       public YbMallServiceException(int code, String message, Throwable cause) {
          super(code, message, cause);
       }
    
    }
    
    异常处理枚举类：

package com.jd.ccc.sys.biz.yb.mall.common.enums;
    
    /**
     * 应答码枚举类
     * 
     * @create 2018-4-28
     * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
     */
    public enum CodeEnum {
    
       /**
        * 处理成功
        */
       SUCCESS(200, "处理成功"),
       /**
        * 入参异常
        */
       ERROR(401, "入参异常"), 
       /**
        * 保存失败
        */
       SAVE_FAIL(402, "保存失败"), 
       /**
        * 查询失败
        */
       QUERY_FAIL(403, "查询失败"),
       /**
        * 未知异常
        */
       UNKOWN_ERROR(404,"未知异常"),
       
       SERVER_ACCESS_FAIL(405, "服务器访问失败");
    
       /**
        * 响应代码
        */
       private final int code;
    
       /**
        * 响应消息
        */
       private final String message;
    
       CodeEnum(int _code, String _message) {
    
          this.code = _code;
          this.message = _message;
    
       }
    
       public int getCode() {
          return code;
       }
    
       public String getMessage() {
          return message;
       }
    
       /**
        * 通过枚举code获取对应的message
        * 
        * @return 取不到时返回null
        * @create 2018-4-28
        * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
        */
       public static String getMessageByCode(int code) {
          for (CodeEnum _enum : values()) {
             if (_enum.getCode() == code) {
                return _enum.getMessage();
             }
          }
          return null;
       }
    
       /**
        * 通过枚举code获取枚举对象
        * 
        * @return 取不到时返回null
        * @create 2018-4-28
        * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
        */
       public static CodeEnum getByCode(int code) {
          for (CodeEnum _enum : values()) {
             if (_enum.getCode() == code) {
                return _enum;
             }
          }
          return null;
       }
    
    }
    响应结果处理类：

package com.jd.ccc.sys.biz.yb.mall.common.res;
    
    import com.jd.ccc.sys.biz.yb.mall.common.enums.CodeEnum;
    
    import lombok.Data;
    import lombok.ToString;
    
    /**
     * 响应结果
     * 
     * @create 2018-4-28
     * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
     */
    @Data
    @ToString
    public class CommonResult {
       /**
        * 应答码
        * 
        * @see 默认值为操作成功
        */
       private int code = CodeEnum.SUCCESS.getCode();
       /**
        * 应答码描述
        * 
        * @see 默认值为操作成功
        */
       private String message = CodeEnum.SUCCESS.getMessage();
       /**
        * 应答数据体
        * 
        * @see 可以为空
        */
       private Object data;
       
       /**
        * 京东账号
        * 
        * @see 可以为空
        */
       private String jdPin;
    
       public CommonResult() {
          this(CodeEnum.SUCCESS.getCode(), CodeEnum.SUCCESS.getMessage(), null);
       }
    
       public CommonResult(CodeEnum codeEnum) {
          this(codeEnum.getCode(), codeEnum.getMessage(), null);
       }
    
       /**
        * 默认返回的code=CodeEnum.SUCCESS.getCode()
        */
       public CommonResult(Object data) {
          this(CodeEnum.SUCCESS.getCode(), CodeEnum.SUCCESS.getMessage(), data);
       }
    
       /**
        * 默认返回的data=null
        */
       public CommonResult(int code, String message) {
          this(code, message, null);
       }
    
       public CommonResult(int code, String message, Object data) {
          this.code = code;
          this.message = message;
          this.data = data;
       }
    
    }

**控制层异常拦截：**

package com.jd.ccc.sys.biz.yb.mall.web.controller.error;
    
    import javax.servlet.http.HttpServletRequest;
    
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.jd.ccc.sys.biz.yb.mall.common.res.CommonResult;
    import com.jd.ccc.sys.biz.yb.mall.common.enums.CodeEnum;
    import com.jd.ccc.sys.biz.yb.mall.common.exception.YbMallException;
    import com.jd.ccc.sys.biz.yb.mall.common.exception.YbMallServiceException;
    
    /**
     * 
     * Controller异常统一处理，因为需要让已经在线上运行的接口不受影响，所以本
     * 次异常处理只扫描“com.jd.ccc.sys.biz.yb.mall.web.controller.v1”包路径下的
     * Controller进行统一的“com.jd.ccc.sys.biz.yb.mall.common.exception.YbMall
     * Exception”和“com.jd.ccc.sys.biz.yb.mall.common.exception.YbMallServiceE
     * xception”这两类自定义异常处理。
     * 
     * @create 2018-4-28
     * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
     *
     */
    @ControllerAdvice(basePackages = "com.jd.ccc.sys.biz.yb.mall.web.controller.v1")
    public class ExceptionAspect {
    
       /**
        * 
        * 统一处理JSON响应结果的错误结果 例如：{"code":201,message:"入参异常",data:null}
        * 
        * @param cause
        *            {
       @link Throwable} 异常
        * @param request
        *            {
       @link HttpServletRequest} 请求
        * @return {
       @link CommonResult} 响应结果
        * 
        * @create 2018-4-28
        * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
        */
       @ResponseBody
       @ExceptionHandler({YbMallException.class, YbMallServiceException.class })
       public CommonResult process(Throwable cause, HttpServletRequest request) {
          CommonResult result = new CommonResult();
          // 判断抛出异常是否为YbMallException
          if (cause instanceof YbMallException) {
             result.setMessage(cause.getMessage());
             result.setCode(((YbMallException) cause).getCode());
          } else {
             result.setCode(CodeEnum.ERROR.getCode());
             result.setMessage(CodeEnum.ERROR.getMessage());
          }
          return result;
       }
    
    }

**说明：****拦截控制层抛出的YbMallException和YbMallServiceException异常。**

**Controller前的通讯异常等处理：**

package com.jd.ccc.sys.biz.yb.mall.web.controller.error;
    
    import org.springframework.boot.autoconfigure.web.ErrorController;
    import org.springframework.http.HttpStatus;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    import com.jd.ccc.sys.biz.yb.mall.common.enums.CodeEnum;
    import com.jd.ccc.sys.biz.yb.mall.common.res.CommonResult;
    
    import javax.servlet.http.HttpServletRequest;
    
    /**
     * Created by wangtianhong1 on 2017/7/6.
     */
    @Controller
    public class ExceptionController implements ErrorController {
    
        private static final String ERROR_PATH = "/error";
    
        @RequestMapping(value=ERROR_PATH,produces = {
      "text/html"})
        public String errorHtml(HttpServletRequest request){
            HttpStatus statusVal = getStatus(request);
            String errorUrl="redirect:/";
            switch (statusVal.value()) {
                case 401: return errorUrl;//重定向首页
                case 404: return errorUrl;
                case 500: return "redirect:https://www.jd.com/error2.aspx";
                default: return  errorUrl;
            }
        }
        
       /**
        * 
        * 针对JSON数据的异常处理
        * 
        * @param request
        *            请求
        * @return {
       @link CommonResult}
        * @create 2018-5-15
        * @author zhangqiang200<https://blog.csdn.net/zhangqiang_accp>
        */
       @RequestMapping(value = ERROR_PATH)
       @ResponseBody
       public CommonResult errorJson(HttpServletRequest request) {
          return new CommonResult(CodeEnum.ERROR);
       }
    
    
        /**
         * 获取错误状态编码
         * @param request
         */
        private HttpStatus getStatus(HttpServletRequest request) {
            Integer statusCode = (Integer) request
                    .getAttribute("javax.servlet.error.status_code");
            if (statusCode == null) {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }
            try {
                return HttpStatus.valueOf(statusCode);
            }
            catch (Exception ex) {
                return HttpStatus.INTERNAL_SERVER_ERROR;
            }
        }
    
        @Override
        public String getErrorPath() {
            return ERROR_PATH;
        }
    
    }