基於Spring AOP實現通用異常攔截器

通常在項目裏，會用大catch包住異常，但是這麼做在生產上將影響問題定位；爲了在項目中更規範的進行編碼，本文將詳細介紹如何基於AOP來實現異常攔截
處理結果：

404請求異常

請求參數異常

一、開啓AspectJ的Proxy設置，使得SpringBoot容器可以解析aop配置

@EnableAspectJAutoProxy(proxyTargetClass = true)

二、定義通用返回邏輯

2.1 通用返回類 CommonRes.class

package com.yfy.dianping.common;

/**
 * @author youfy
 */
public class CommonRes {
    /**
     *請求的返回處理結果，"success"或"fail"
     */
    private String status;
    /**
     * 若status=success時，表明對應的返回的json類數據
     * 若status=fail時，則data內將使用通用的錯誤碼對應的格式
     */
    private Object data;
    /**
     *定義一個通用的創建返回對象的方法
     */
    public static CommonRes create(Object result){
        return CommonRes.create(result,"success");
    }

    public static CommonRes create(Object result,String status){
        CommonRes commonRes = new CommonRes();
        commonRes.setStatus(status);
        commonRes.setData(result);
        return commonRes;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public Object getData() {
        return data;
    }

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

2.2 通用異常類 CommonError.class

package com.yfy.dianping.common;

/**
 * @author youfy
 */
public class CommonError {
    /**
     * 錯誤碼
     */
    private Integer errCode;
    /**
     * 錯誤描述
     */
    private String errMsg;

    public CommonError(Integer errCode, String errMsg) {
        this.errCode = errCode;
        this.errMsg = errMsg;
    }

    public CommonError(EmBusinessError emBusinessError){
        this.errCode = emBusinessError.getErrCode();
        this.errMsg = emBusinessError.getErrMsg();
    }
    public Integer getErrCode() {
        return errCode;
    }

    public void setErrCode(Integer errCode) {
        this.errCode = errCode;
    }

    public String getErrMsg() {
        return errMsg;
    }

    public void setErrMsg(String errMsg) {
        this.errMsg = errMsg;
    }
}

2.3業務異常 BusinessException.class

package com.yfy.dianping.common;

/**
 * @author youfy
 */
public class BusinessException extends Exception {
    private CommonError commonError;

    public BusinessException(EmBusinessError emBusinessError){
        super();
        this.commonError = new CommonError(emBusinessError);
    }

    public CommonError getCommonError() {
        return commonError;
    }

    public void setCommonError(CommonError commonError) {
        this.commonError = commonError;
    }
}

2.4 異常枚舉 EmBusinessError.class

package com.yfy.dianping.common;

/**
 * @author youfy
 */

public enum EmBusinessError {
    //通用的錯誤類型以10000開頭
    NO_OBJECT_FOUND(10001, "請求對象不存在"),
    UNKNOWN_ERROR(10002, "未知異常"),
    NO_HANDLE_FOUND(10003, "找不到執行的路徑操作"),
    BIND_EXCEPTION_ERROR(10004, "請求參數錯誤"),

    ;

    private Integer errCode;

    private String errMsg;

    EmBusinessError(Integer errCode, String errMsg) {
        this.errCode = errCode;
        this.errMsg = errMsg;
    }

    public Integer getErrCode() {
        return errCode;
    }

    public void setErrCode(Integer errCode) {
        this.errCode = errCode;
    }

    public String getErrMsg() {
        return errMsg;
    }

    public void setErrMsg(String errMsg) {
        this.errMsg = errMsg;
    }
}

三、定義全局異常處理器，使用@ControllerAdvice可覆蓋所有controller

全局異常處理器 GlobalExceptionHandler.class

package com.yfy.dianping.common;

import org.springframework.web.bind.ServletRequestBindingException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.NoHandlerFoundException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * @author youfy
 */
@ControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(Exception.class)
    @ResponseBody
public CommonRes doError(HttpServletRequest httpServletRequest,HttpServletResponse httpServletResponse,
                         Exception ex) {
  	  if (ex instanceof BusinessException) {
            return CommonRes.create(((BusinessException) ex).getCommonError(), "fail");
        } else if (ex instanceof NoHandlerFoundException) {
            CommonError commonError = new CommonError(EmBusinessError.NO_HANDLE_FOUND);
            return CommonRes.create(commonError, "fail");
        } else if (ex instanceof ServletRequestBindingException) {
            CommonError commonError = new CommonError(EmBusinessError.BIND_EXCEPTION_ERROR);
            return CommonRes.create(commonError, "fail");
        } else {
            CommonError commonError = new CommonError(EmBusinessError.UNKNOWN_ERROR);
            return CommonRes.create(commonError, "fail");
        }
    }
}

四、處理404請求異常，設置：拒絕404默認的處理，如果沒找到處理器就拋出異常

application.properties下配置：

spring.resources.add-mappings=true
spring.mvc.throw-exception-if-no-handler-found=true

五、處理請求參數異常，用ServletRequestBindingException捕獲

if (ex instanceof NoHandlerFoundException) {
	            CommonError commonError = new CommonError(EmBusinessError.NO_HANDLE_FOUND);
	            return CommonRes.create(commonError, "fail");
 }