I have a socket listening to a certain port in PHP, and I am trying to send a string using a socket in Java, but I keep getting the following error:
Warning: socket_recv(): unable to read from socket [0]: The operation completed successfully.
in H:\Dropbox\EISTI\www\java-instagram-web\src\Client\Component\Server\Client.php on line 55
Without any more description, it is hard to understand what is the problem.
My PHP class looks like the following:
class Client {
private $address;
private $port;
private $command;
public function __construct($port, $address, $addressServer, $portServer, $command)
{
set_time_limit(0);
$this->address = $address;
$this->port = $port;
$this->init();
}
private function init(){
//Create socket
if (! $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) {
$this->showError('socket create');
}
echo "Server Created\n";
//Bind socket
if (!socket_bind($socket, $this->address, $this->port)) {
$this->showError('socket bind');
}
echo "Server bind to $this->address and $this->port \n";
if (!socket_listen($socket)) {
$this->showError('socket listen');
}
echo "Server Listening \n";
do {
$client = socket_accept($socket);
echo "connection established\n";
$message = "\n Hey! welcome to the server\n";
socket_write($client, $message, strlen($message));
do {
if (! socket_recv($socket, $clientMessage, 2045, MSG_WAITALL)) {
$this->showError('socket receive');
}
$message = "Command Received\n";
echo $clientMessage;
socket_send($client, $message, strlen($message), 0);
if (!$clientMessage = trim($clientMessage)) {
continue;
}
if (trim($clientMessage) == 'close') {
socket_close($client);
echo "\n\n--------------------------------------------\n".
"ClientRequest terminated\n";
break 1;
}
} while(true);
} while(true);
}
private function showError($message) {
echo ("Error: ".$message);
exit(666);
}
}
And my Java socket class looks like the following:
public class ResponseToClient {
private String host;
private int port;
private Socket socket;
private PrintStream theOut;
private String resultLocation;
/**
* Constructor
*/
public ResponseToClient(String path) {
this.host = "localhost";
this.port = 1000;
this.resultLocation = path;
}
/**
* Setting up Socket
*/
public void init(){
try{
socket = new Socket(host, port);
theOut = new PrintStream(socket.getOutputStream());
//Send Command
sendCommand();
//Closing connections
socket.close();
theOut.close();
}
catch (IOException e){
e.printStackTrace();
}
}
/**
* Send Command
*/
public void sendCommand()
{
theOut.println(Messages.type_response + Messages.seperator_client + resultLocation);
System.out.println(Messages.type_response + Messages.seperator_client + resultLocation);
}
}
What am I doing wrong?
I figured out the problem.
There were two problems, I was reading from the wrong socket, So i made the change as suggested by @RealSkeptic, changing from :
socket_recv($socket, $clientMessage, 2045, MSG_WAITALL)
To
socket_recv($client, $clientMessage, 2045, MSG_WAITALL)
And Another Problem was the inner while loop that I was using was which was en-globing the socket_read.
I did it this way, because I had got this code off a tutorial I found for server_sockets in PHP.
But it created a problem here because of the flow of the communication:
Answer:
On the Java side I was sending only one single response, whereas on the PHP side I was using socket_read "infinitely" in the while loop until I received the string "close". This was creating the problem because, after receiving the first response, there is nothing else to read. Thus the error.
So to solve the problem I just had to remove the while loop, (and I removed the socket_write as for my purpose I do not need to send any information).
The working example for the class Client:
class Client {
private $addressServer;
private $portServer;
private $address;
private $port;
private $command;
public function __construct($port, $address, $addressServer, $portServer, $command)
{
set_time_limit(0);
$this->addressServer = $addressServer;
$this->address = $address;
$this->portServer = $portServer;
$this->port = $port;
$this->command = $command;
$this->init();
}
private function init() {
//Send request to the Java server
$request = new Request(
$this->addressServer, $this->portServer, $this->command
);
//create socket
if (! $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP)) {
$this->showError('socket create');
}
echo "Server Created\n";
//Bind socket
if (!socket_bind($socket, $this->address, $this->port)) {
$this->showError('socket bind');
}
echo "Server bind to $this->address and $this->port \n";
if (!socket_listen($socket)) {
$this->showError('socket listen');
}
echo "Server Listening \n";
do {
$client = socket_accept($socket);
echo "connection established\n";
if(!$clientMessage = socket_read($client, 10000, PHP_NORMAL_READ)){
$this->showError('socket read');
}
echo "Command Received\n";
echo $clientMessage;
} while(true);
}
private function showError($message){
echo ("Error: ".$message);
exit(666);
}
}