全局異常主要處理controller中拋出的異常，需註意controller中不需要捕獲異常

一、@ControllerAdvice + @ExceptionHandler 實現全局異常處理

1、@ControllerAdvice 中申明@ExceptionHandler 方法，對所有controller中的@RequestMapping方法有效。

2、@Controller 中申明@ExceptionHandler 方法，僅對當前controller中的@RequestMapping方法有效。

全局異常處理類GlobalErrorHandler .java代碼如下(需保證該類所在路徑可以被掃描加載到spring容器

package com.tianwen.dcdp.exception.handler;

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

import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.view.json.MappingJackson2JsonView;

@ControllerAdvice
 
public class GlobalErrorHandler {

    /**
     * 檢查是否ajax請求
     * @param request
     * @return
     */
    public static boolean isAjax(HttpServletRequest request) {
        return request.getHeader("X-Requested-With") != null &&
                "XMLHttpRequest".equalsIgnoreCase(request.getHeader("
 
X-Requested-With"));
    }
    
    /**
     * 全局異常處理
     * @param request
     * @param response
     * @param ex
     * @return
     * @throws Exception
     */
    @ExceptionHandler(Exception.class)
    public Object errorHandler(HttpServletRequest request,
            HttpServletResponse response,
            Exception ex) throws Exception{
        if(isAjax(request)) {
            //如果是ajax請求，返回json數據
            ModelAndView mav = new ModelAndView(new MappingJackson2JsonView());
            mav.addObject("result", 0);
            mav.addObject("msg", ex.getMessage());
            return mav;
        } else {
            //如果不是ajax請求，跳轉到錯誤頁面
            ModelAndView mv = new ModelAndView();
            mv.addObject("exception", ex);
            mv.addObject("url", request.getRequestURL());
            mv.addObject("msg", ex.getMessage());
            if(request.getRequestURL().toString().contains("/m/")) {
                mv.setViewName("m/error");
            } else {
                mv.setViewName("error");
            }
            return mv;
        }
    }
    
}

spring 部分配置如下：

<!-- 自動掃描 -->
    <context:component-scan base-package="com.tianwen.dcdp">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        <context:exclude-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    </context:component-scan>

springmvc部分配置如下：

<context:component-scan base-package="com.tianwen.dcdp.*">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        <context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.ControllerAdvice"/>
    </context:component-scan>

如此便可實現異常的統一處理

未完待續

springMVC--全局異常處理