java使用HttpURLConnection发送Post数据

    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();

        byte[] buffer = new byte[10240];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        inStream.close();

        return outStream.toByteArray();
    }
    
    public static String sendPost(String urlStr, String dataStr, String paramsStr) {
        String result = "";

        try {
            byte[] data = dataStr.getBytes("UTF-8");

            URL url = new URL(urlStr);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setDoOutput(true);
            conn.setDoInput(true);
            conn.setUseCaches(false);
            conn.setRequestMethod("POST");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.setRequestProperty("Charset", "UTF-8");
            conn.setRequestProperty("Content-Length", String.valueOf(data.length));
            conn.setRequestProperty("Content-Type", "text/xml");
            conn.connect();

            OutputStream  out = conn.getOutputStream();
            out.write(data);
            out.flush();
            out.close();

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

            if (conn.getResponseCode() == 200) {
                System.out.println("连接成功");
                InputStream in = conn.getInputStream();
                byte[] data1 = readInputStream(in);
                result = new String(data1);

            } else {
                System.out.println("连接失败");
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        return result;
    }