Struts2 Exception拦截 HTTP请求与Ajax请求

<package name="publicPackage" extends="json-default">

<interceptors>
<!-- seven -->
<interceptor name="exceptionInterceptor" class="org.vbs.front.common.intercept.ExceptionInterceptor"></interceptor>

<interceptor-stack name="userStack">
<!-- seven -->
<interceptor-ref name="exceptionInterceptor"></interceptor-ref>
<interceptor-ref name="defaultStack"></interceptor-ref>
</interceptor-stack>

</interceptors>

<default-interceptor-ref name="userStack"></default-interceptor-ref>

<global-results>
<result name="exception" type="json">
　　<param name="root">exceptionResult</param>
　　　　　　　　　　　　　　</result>
</global-results>

</package>

package org.vbs.front.common.intercept;

import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.HashMap;

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

import org.apache.log4j.Logger;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.StrutsStatics;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
import com.opensymphony.xwork2.util.ValueStack;

/*
* seven
* 异常获取拦截器，在action中将exception抛出，
* 			   若一般请求则会跳转到dennied页面，
* 			   若为ajax请求，则会返回json数据 {"success":"false","message":"抛出的错误信息" }
*
*/
public class ExceptionInterceptor implements Interceptor {

@Override
public void destroy() {
// TODO Auto-generated method stub

}

@Override
public void init() {
// TODO Auto-generated method stub

}

@Override
public String intercept(ActionInvocation invocation) throws Exception {
// TODO Auto-generated method stub
String result = null; // Action的返回值
try {
// 运行被拦截的Action,期间如果发生异常会被catch住
result = invocation.invoke();
return result;
} catch (Exception e) {
/**
* 处理异常
*/
String errorMsg = "出现错误信息，请查看日志！";
/**
* log4j记录日志
*/
Logger log = Logger.getLogger(invocation.getAction().getClass());
log.error(errorMsg, e);

HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();
//分ajax请求与普通请求
if (request.getHeader("accept").indexOf("application/json") > -1
|| (request.getHeader("X-Requested-With")!= null && request.getHeader("X-Requested-With").indexOf("XMLHttpRequest") > -1)) {
/* seven
* ajax返回json
* 数据格式为 {"success":"false",
*         "message":"exception信息" }
*/
System.out.println("Ajax请求回应(exception)");
ValueStack stack = invocation.getStack();
HashMap<String, Object> exceptionResult = new HashMap<String, Object>();
stack.set("exceptionResult", exceptionResult);
exceptionResult.put("success", "false");
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
e.printStackTrace(pw);
exceptionResult.put("message", sw.getBuffer().toString());
return "exception";
}
else{//如果是普通请求
System.out.println("正常请求回应(exception)");
return "denied";
}
}
}

}

$.ajax({
url : "subjectMaintenance!toCreateSubjectMaintenance.action",
data : $("#createSubject_queryForm").serialize(),
type : "post",
success : function(data) {
hidemask();
if(data.success=="false"){
$.messager.alert(selectLang("提示","提示","tip"), selectLang("创建失败！","創建失敗！","Create fail!"));
}else{

}
}
});