JAVA处理外部链接的方法

js中直接同步、异步调用外部系统链接失效，或者无返回值等情况的判断与处理。

首先要用同步、异步几种方式测试该链接是否有效，当无效后引入下面jsp代码，该代码文件是被调用文件：

<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<%@ page import="org.apache.commons.httpclient.*"%>
<%@ page import="org.apache.commons.httpclient.methods.GetMethod"%>
<%@ page import="java.io.*"%>
<%
 String getString = "";
 String httpurl = request.getParameter("getMailUrl");
 if(httpurl != null && !"".equals(httpurl)){
  httpurl = java.net.URLDecoder.decode(httpurl,"UTF-8");
  HttpClient httpclient = new HttpClient();
  HttpMethod method = null;
  method = new GetMethod(httpurl);
  try {
      httpclient.executeMethod(method);
      getString = method.getResponseBodyAsString();
  } catch (HttpException e) {
      e.printStackTrace();
  } catch (IOException e) {
      e.printStackTrace();
  }
 }
out.print(getString);
%>

2.这里是个取外部邮件的例子，附上调用代码文件

var url = 'http://10.2.10.4/cgi-bin/getnewnum?domain=*****.com&username=<%=accountMail[0]%>';
 var getMailUrl = "/defaultroot/public/jsp/ajax_******.jsp?getMailUrl="+encodeURIComponent(url);
 var dlzgMailCount = $.trim(com_ajax_ReqDo(getMailUrl));

//调用函数

function com_ajax_ReqDo(url){
 var redata='';
 $.ajaxSetup({ async : false });
    $.get(url,function(data){
        redata = data;
    });
 $.ajaxSetup({ async : true });
 return redata;
}