java发送http的post请求

/** * 向指定 URL 发送POST方法的请求 * * @param url * 发送请求的 URL * 请求参数 * @return 所代表远程资源的响应结果 */ public static String sendPost(String url, Map paramMap) { PrintWriter out = null; BufferedReader in = null; String result = ""; String param = ""; Iterator it = paramMap.keySet().iterator(); while (it.hasNext()) { String key = it.next(); param += key + "=" + paramMap.get(key) + "&"; } try { URL realUrl = new URL(url); // 打开和URL之间的连接 URLConnection conn = realUrl.openConnection(); // 设置通用的请求属性 conn.setRequestProperty("accept", "*/*"); conn.setRequestProperty("connection", "Keep-Alive"); conn.setRequestProperty("Accept-Charset", "utf-8"); conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)"); // 发送POST请求必须设置如下两行 conn.setDoOutput(true); conn.setDoInput(true); // 获取URLConnection对象对应的输出流 out = new PrintWriter(conn.getOutputStream()); // 发送请求参数 out.print(param); // flush输出流的缓冲 out.flush(); // 定义BufferedReader输入流来读取URL的响应 in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8")); String line; while ((line = in.readLine()) != null) { result += line; } } catch (Exception e) { System.out.println(e); } // 使用finally块来关闭输出流、输入流 finally { try { if (out != null) { out.close(); } if (in != null) { in.close(); } } catch (IOException ex) { ex.printStackTrace(); } } return result; }