网络传输---HttpURLConnection

URL url = new URL(urlString);

 HttpURLConnection httpUrlConnection = (HttpURLConnection) url.openConnection();

//设置HttpURLConnection参数 ???????????httpUrlConnection.setRequestMethod("POST"); ???????????// 设置是否向httpUrlConnection输出，因为这个是post请求，参数要放在 ???????????// http正文内，因此需要设为true, 默认情况下是false; ???????????httpUrlConnection.setDoOutput(true); ???????????// 设置是否从httpUrlConnection读入，默认情况下是true; ???????????httpUrlConnection.setDoInput(true); ???????????//设置不使用缓存 ???????????httpUrlConnection.setUseCaches(false); ???????????//设置发送请求为utf-8 ???????????httpUrlConnection.setRequestProperty("Content-type", "text/html;charset=utf-8"); ???????????//设置网络请求时间最多为5秒； ???????????httpUrlConnection.setConnectTimeout(5000); ???????????//读取网页请求结果时间为15秒 ???????????httpUrlConnection.setReadTimeout(25000);

// 连接，从上述url.openConnection()至此的配置必须要在connect之前完成， ???????????httpUrlConnection.connect();

//输出 ???????????OutputStream out = httpUrlConnection.getOutputStream(); ???????????//用到了缓存流,提高IO效率,由于数据为字符,用到字符转字节的包装流,并设置UTF-8编码 ???????????BufferedWriter bout = new BufferedWriter(new OutputStreamWriter(out,"utf-8")); ???????????bout.write("demo"); ???????????bout.flush(); ???????????bout.close();

 //获得返回结果 ???????????if (httpUrlConnection.getResponseCode() == httpUrlConnection.HTTP_OK) {//判断状态码是否为200 ???????????????????InputStream in = httpUrlConnection.getInputStream(); ???????????????????BufferedReader reader = new BufferedReader(new InputStreamReader( ???????????????????????????in)); ???????????????????StringBuffer stringBuffer = new StringBuffer(); ???????????????????String str = ""; ???????????????????while ((str = reader.readLine()) != null) { ???????????????????????????stringBuffer.append(str+"\n"); ???????????????????} ???????????????????reader.close(); ???????????????????in.close(); ???????????????????return stringBuffer.toString(); ???????????}else{ ???????????????????return null; ???????????}