HttpClient应用

用HttpClient爬网站时有时会遇到一种现象，就是自己写个JSP模拟表单提交可以成功，但是用HttpClient就无法成功。

原因有可能是Header或者Cookies没有设置，因为如果用游览器访问的话，这些参数都可以通过游览器而取到，不需要自己手动设置，而HttpClient则无法做到。所以我们需要对HttpClient进行设置，完整的代码如下：

 

 

 

 

public static String  HttpClientCIB()
	{
	      //添加header信息

              List <Header> headers = new ArrayList <Header>();  
	      headers.add(new Header("Referer", "http://wap.sududa.com/default.aspx"));  
	      headers.add(new Header("User-Agent", "http://wap.sududa.com/default.aspx"));  
	      headers.add(new Header("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8"));  
	      headers.add(new Header("User-Agent", "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)"));  
	      headers.add(new Header("Accept-Language", "zh-cn,zh;q=0.5"));  
	      headers.add(new Header("Host", "wap.sududa.com"));  
	      headers.add(new Header("Accept-Charset", "GB2312,utf-8;q=0.7,*;q=0.7"));  


     	HttpClient httpclient = new HttpClient();
        httpclient.getHostConfiguration().getParams().setParameter("http.default-headers", headers);    
		httpclient.getHostConfiguration().setProxy( "202.84.17.41",8080);
		httpclient.getHttpConnectionManager().getParams().setConnectionTimeout(50);
		
		String result="";
	  
		  PostMethod httppost = new PostMethod("http://wap.sududa.com/wap/default.aspx"); 
          httppost.getParams().setContentCharset("GB2312");
		  httppost.setRequestHeader("Connection", "close");

		  
               //添加两个Cookie信息
		  httpclient.getParams().setCookiePolicy(CookiePolicy.RFC_2109);//RFC_2109是支持较普遍的一个，还有其他cookie协议  
		  HttpState initialState = new HttpState();  
		  
		  Cookie SUDUDA_COM_WapBalance = new Cookie();  
		  SUDUDA_COM_WapBalance.setDomain("wap.sududa.com");  
		  SUDUDA_COM_WapBalance.setPath("/");  
		  SUDUDA_COM_WapBalance.setName("SUDUDA_COM_WapBalance");  
		  SUDUDA_COM_WapBalance.setValue("0.000");  
		  
		  Cookie SUDUDA_COM_WapKey = new Cookie();  
		  SUDUDA_COM_WapKey.setDomain("wap.sududa.com");  
		  SUDUDA_COM_WapKey.setPath("/");  
		  SUDUDA_COM_WapKey.setName("SUDUDA_COM_WapKey");  
		  SUDUDA_COM_WapKey.setValue("56643CAF26F5A7751F1097F4B3D01AC4");  
		  
		
		  
		  
		  initialState.addCookie(SUDUDA_COM_WapBalance);  
		  initialState.addCookie(SUDUDA_COM_WapKey);  

		  
		  
		  
		  httpclient.setState(initialState);  

		  
		  NameValuePair[] data = { 
				new NameValuePair("__VIEWSTATE", "/wEPDwUKMjAzOTY2ODc0NmRkkLuRhKYz6SYsEOIBQM8bHuiWt2k="),
				new NameValuePair(".logontest", ""),
				new NameValuePair("Name", "readls@163.com"),
				new NameValuePair("Pass","changwei"),
		
		  };
        		httppost.setRequestBody(data);
                InputStream is = null;
        try { 
		    httpclient.executeMethod(httppost);

          BufferedReader bf = new BufferedReader(new InputStreamReader(httppost.getResponseBodyAsStream()));
	//	  result=httppost.getResponseBodyAsStream();
		  

          String line;

          StringBuffer paramter= new StringBuffer();
          while ((line = bf.readLine()) != null){
          //    System.out.println(line);
         
              paramter=paramter.append(line);
          }

          bf.close();
          
          result=paramter.toString();
		  result=result.replaceAll("\n","");
          result=result.replaceAll("\r","");
          result=result.replaceAll("\t","");         
    //      System.out.println("||"+result+"||");

		  }catch( Exception e){
			  e.printStackTrace();
		  } 
		  finally {
		    httppost.releaseConnection();
		  }
		  return result;
	}

 

 

    有一种特殊情况，就是传递的参数是不固定的，也就是说其中一个参数是要给对方传递一个数组，例如groupIds这个参数是一个数组，给对方传过去时是.do?groupIds=1&&groupIds=2这种。所以不能用传统的直接赋值，NameValuePair[] data = { new NameValuePair("name",1)，new NameValuePair("age",20)};这种，只能初始化数组时就给定长度。

例：

 

			NameValuePair[] data = new NameValuePair[groupId.size()+7];  

			


		 			 String categoryName= globalContext.getArticleSysCategoryManager().getCategoryNameById(article.getSystemCategoryId());
					 data[0] = new NameValuePair("operName", article.getUserName());
					 data[1] = new NameValuePair("title", article.getTitle());
					 data[2] = new NameValuePair("tag", article.getTagWords());
					 data[3] = new NameValuePair("srcContentId",String.valueOf(article.getId()));
					 data[4] = new NameValuePair("itemType", "4");
					 data[5] = new NameValuePair("category", categoryName);
					 data[6] = new NameValuePair("srcUrl", articleURL);
					 
					
					for(int j=0;j<groupId.size();j++){
					
				
						data[j+7] = new NameValuePair("groupIds", String.valueOf(groupId.get(j)));
					}
				
					
				
			httppost.setRequestBody(data);

 

想获得该网页的Header和Cookie信息，可以通过HttpWatch工具。