使用UrlConnection实现后台模拟http请求的简单实例

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");   } } 

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