java使用HttpURLConnection发送Post数据

    public static String sendPost(String urlStr, String dataStr) {

        String result = "";
        try {

            // 创建url资源
            URL url = new URL(urlStr);
            // 建立http连接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            // 设置允许输入输出
            conn.setDoOutput(true);
            conn.setDoInput(true);

            // 设置不用缓存
            conn.setUseCaches(false);
            // 设置传递方式
            conn.setRequestMethod("POST");
            // 设置维持长连接
            conn.setRequestProperty("Connection", "Keep-Alive");
            // 设置文件字符集:
            conn.setRequestProperty("Charset", "UTF-8");
            //转换为字节数组
            byte[] data = dataStr.getBytes("UTF-8");
            // 设置文件长度
            conn.setRequestProperty("Content-Length", String.valueOf(data.length));
            // 设置文件类型:
            conn.setRequestProperty("Content-Type", "text/xml");// 开始连接请求
            conn.connect();
            OutputStream  out = conn.getOutputStream();
            // 写入请求的字符串
            out.write(data);
            out.flush();
            out.close();

            System.out.println(conn.getResponseCode());

            // 请求返回的状态
            if (conn.getResponseCode() == 200) {
                System.out.println("连接成功");
                // 请求返回的数据
                InputStream in = conn.getInputStream();try {
                    byte[] data1 = new byte[in.available()];
                    in.read(data1);
                    result = new String(data1);
                } catch (Exception e1) {
                    // TODO Auto-generated catch block
                    e1.printStackTrace();
                }
            } else {
                System.out.println("no++");
            }

        } catch (Exception e) {

        }


        return result;
    }