使用UrlConnection实现后台模拟http请求的简单实例

使用urlconnection实现后台模拟http请求的简单实例

这两天在整理看httpclient，然后想自己用urlconnection后台模拟实现http请求，于是一个简单的小例子就新鲜出炉了（支持代理哦）：

public class simplehttptest { 
 
  public static string send(string urlstr, map<string,string> map,string encoding){ 
    string body=""; 
    stringbuffer sbuf = new stringbuffer(); 
    if(map!=null){ 
      for (entry<string,string> entry : map.entryset()) { 
        sbuf.append(entry.getkey()).append("=").append(entry.getvalue()).append("&"); 
      } 
      if(sbuf.length()>0){ 
        sbuf.deletecharat(sbuf.length()-1); 
      } 
    } 
     // 1、重新对请求报文进行 gbk 编码 
    byte[] postdata = null; 
    try { 
      postdata = sbuf.tostring().getbytes(encoding); 
    } catch (unsupportedencodingexception e) { 
      e.printstacktrace(); 
    } 
 
    // 2、发送 http(s) 请求 
    outputstream reqstream = null; 
    inputstream resstream = null; 
    urlconnection request = null; 
    try { 
      system.out.println("交易请求地址：" + urlstr); 
      system.out.println("参数：" + sbuf.tostring()); 
       
      //a、与服务器建立 http(s) 连接 
      url url = null; 
      try { 
        proxy proxy = new proxy(java.net.proxy.type.http,new inetsocketaddress("127.0.0.1", 8087)); 
        url = new url(urlstr); 
        request = url.openconnection(proxy); 
        request.setdoinput(true); 
        request.setdooutput(true); 
      } catch (malformedurlexception e) { 
        e.printstacktrace(); 
      } catch (ioexception e) { 
        e.printstacktrace(); 
      } 
       
      //b、指定报文头【content-type】、【content-length】 与 【keep-alive】 
      request.setrequestproperty("content-type", "application/x-www-form-urlencoded"); 
      request.setrequestproperty("content-length", string.valueof(postdata.length)); 
      request.setrequestproperty("keep-alive", "false"); 
      request.setrequestproperty("user-agent", "mozilla/4.0 (compatible; msie 5.0; windows nt; digext)"); 
       
      //c、发送报文至服务器 
      reqstream = request.getoutputstream(); 
      reqstream.write(postdata); 
      reqstream.close(); 
       
      //d、接收服务器返回结果 
      bytearrayoutputstream ms = null; 
      resstream = request.getinputstream(); 
      ms = new bytearrayoutputstream(); 
      byte[] buf = new byte[4096]; 
      int count; 
      while ((count = resstream.read(buf, 0, buf.length)) > 0) { 
        ms.write(buf, 0, count); 
      } 
      resstream.close(); 
      body = new string(ms.tobytearray(), encoding); 
    } catch (unknownhostexception e) { 
      system.err.println( "服务器不可达【" + e.getmessage() + "】"); 
    } catch (ioexception e) { 
      e.printstacktrace(); 
    } finally { 
      try { 
        if (reqstream != null) 
          reqstream.close(); 
        if (resstream != null) 
          resstream.close(); 
      } catch (exception ex) { 
      } 
    } 
 
    system.out.println("交易响应结果："); 
    system.out.println(body); 
    return body; 
  } 
   
  public static void main(string[] args) { 
    string url="http://php.weather.sina.com.cn/iframe/index/w_cl.php"; 
    map<string, string> map = new hashmap<string, string>(); 
    map.put("code", "js"); 
    map.put("day", "0"); 
    map.put("city", "上海"); 
    map.put("dfc", "1"); 
    map.put("charset", "utf-8"); 
    send(url, map,"utf-8"); 
  } 
} 

结果如下：

交易请求地址：http://php.weather.sina.com.cn/iframe/index/w_cl.php 
参数：dfc=1&charset=utf-8&day=0&code=js&city=上海 
交易响应结果： 
(function(){var w=[];w['上海']=[{s1:'阴',s2:'阴',f1:'yin',f2:'yin',t1:'17',t2:'14',p1:'≤3',p2:'≤3',
d1:'东北风',d2:'东北风'}];var add={now:'2015-11-11 19:04:33',time:'1447239873',update:'
北京时间11月11日17:10更新',error:'0',total:'1'};window.swther={w:w,add:add};})();//0 

代码中的步骤写的很明白了，如果你有心，还可以对该方法进行各种封装，方便使用。下篇我会分享一下httpclient是如何模拟后台来发送http请求的，还有配置ssl、代理、自定义header等等，敬请期待吧。

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