Java发送HTTP的POST请求

import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.URL;import java.util.Map;import java.util.Map.Entry; /** * @author yoUng * @description 发送http请求 * @filename HttpUtil.java * @time 2011-6-15 下午05:26:36 * @version 1.0 */public class HttpUtil { public static String http(String url, Map<String, String> params) {URL u = null;HttpURLConnection con = null;//构建请求参数StringBuffer sb = new StringBuffer();if(params!=null){for (Entry<String, String> e : params.entrySet()) {sb.append(e.getKey());sb.append("=");sb.append(e.getValue());sb.append("&");}sb.substring(0, sb.length() - 1);}System.out.println("send_url:"+url);System.out.println("send_data:"+sb.toString());//尝试发送请求try {u = new URL(url);con = (HttpURLConnection) u.openConnection();con.setRequestMethod("POST");con.setDoOutput(true);con.setDoInput(true);con.setUseCaches(false);con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");OutputStreamWriter osw = new OutputStreamWriter(con.getOutputStream(), "UTF-8");osw.write(sb.toString());osw.flush();osw.close();} catch (Exception e) {e.printStackTrace();} finally {if (con != null) {con.disconnect();}} //读取返回内容StringBuffer buffer = new StringBuffer();try {BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream(), "UTF-8"));String temp;while ((temp = br.readLine()) != null) {buffer.append(temp);buffer.append("\n");}} catch (Exception e) {e.printStackTrace();} return buffer.toString();} }