java和php之间的简单客户端服务器通信

我需要从php客户端向java服务器发送信息，但是没有一个在服务器端接收，尽管在服务器上成功执行了一个print语句，客户端的文本无法在服务器端接收。以下是代码：

I need to send information from php client to java server, but none is receiving on server side though one print statement is successfully executed on server, the text from client is not able to receive on the server side. Here are the codes:

Java服务器：

import java.io.BufferedReader;
import java.net.*;
import java.io.*;

public class javaphp2 {
    private static ServerSocket socket;

    private static Socket connection;
    private static String command       = new String();
    private static String responseStr   = new String();

    private static int port = 4309;

    public static void main(String args[])  {
        System.out.println("Signal Server is running.");

        try  {
            socket = new ServerSocket(port);

            while (true)  {
                connection = socket.accept();

                InputStreamReader inputStream = new InputStreamReader(connection.getInputStream());
                DataOutputStream response = new DataOutputStream(connection.getOutputStream());
                BufferedReader input = new BufferedReader(inputStream);

                command = input.readLine();
                //System.out.println("The input is" + command);
                response.writeBytes(responseStr);
                response.flush();
                //response.close();

                System.out.println("Running");
            }
        } catch (IOException e)  {
            System.out.println("Fail!: " + e.toString());
        }

        System.out.println("Closing...");
    }
}

PHP客户端：

#!/usr/local/bin/php -q
<?php
$address = '132.119.90.165';
$port = 4309;

$socket = socket_create(AF_INET, SOCK_STREAM, getprotobyname('tcp'));
socket_connect($socket, $address, $port);

$message = 'Apple';
$len = strlen($message);

$status = socket_sendto($socket, $message, $len, 0, $address, $port);
if($status !== FALSE)
{
    $message = '';
    $next = '';
    while ($next = socket_read($socket, 4096))
    {
        $message .= $next;
    }

    echo $message;
}
else
{
    echo "Failed";
}

socket_close($socket);
?>