// Comes from client to server when user clicks "Send"
class ChatMessage {
	public $from;
	public $to; // Optional
	public $message;
}
 
// List of these objects is by server to client
class ChatEvent {
	public $id;	
	public $from;
	public $to;
	public $text;
}
 
// This object holds list of recent chat events that occurred
// after event with ID=$lastId.
// Instances of this object are returned by Chat service methods.
class ChatEvents {
	public $events = array(); // Array of ChatEvent
	public $lastId;
}
 
// This interface will be provided via SOAP
interface Chat {
	// Returns ChatEvents
	public function Send($params);
 
	// Returns ChatEvents
	public function Poll($params);
}

extension=php_soap.dll

<?php
$server = new SoapServer("chat.wsdl"); // Path to the service WSDL declaration
$server->setObject(new ChatImpl()); // ChatImpl is the service implementation (see below)
$server->handle();
?>

<?php
// server.php, SOAP chat sevice
define("CHAT_FILE", "data/chat.txt");
 
// Disable WSDL cache for debugging
ini_set("soap.wsdl_cache_enabled", 0);
 
////////////////////////////////////////////////////
// Public interface declaration (mirrors the WSDL stuff)
 
// Comes from client to server when user clicks "Send"
class ChatMessage {
    public $from;
    public $to; // Optional
    public $message;
}
 
// List of these objects is by server to client
class ChatEvent {
    public $id;
    public $from;
    public $to;
    public $text;
}
 
// This object holds list of recent chat events that occurred
// after event with ID=$lastId.
// Instances of this object are returned by Chat service methods.
class ChatEvents {
    public $events = array(); // Array of ChatEvent
    public $lastId;
}
 
// This interface will be provided via SOAP
interface Chat {
    // Returns ChatEvents
    public function Send($param);
 
    // Returns ChatEvents
    public function Poll($param);
}
 
////////////////////////////////////////////////////
 
// Holds internal server data
class ChatData {
    public $events = array(); // Array of ChatEvent
    public $lastId;
}
 
class ChatImpl implements Chat {
 
    public function Send($param) {
        $messageIn = $param->message; 
        $msg = new ChatEvent();
        $msg->from = $messageIn->from;
        $msg->to = $messageIn->to;
        $msg->text = trim($messageIn->text);
        if(strlen($msg->text) < 1) {
            $msg = null;
        }
        $this->handleChatMessage($msg);
 
        return $this->getEvents($param->lastId); // Return recent messages
    }
 
    public function Poll($param) {
        $this->handleChatMessage(null); // Load messages
        return $this->getEvents($param->lastId); // Return recent messages
    }
 
    private function getEvents($lastId) {
        $filtered = $this->filterEvents($this->chatData->events, $lastId);
        $result = new ChatEvents();
        $result->events = $filtered;
        $result->lastId = $this->chatData->lastId;
        return $result;
    }
 
    private function filterEvents($events, $lastId) {
        $result = array();
        foreach($events as $evt) {
            if($evt->id > $lastId) {
                $result[] = $evt;
            }
        }
        return $result;
    }
 
    private $filePath = CHAT_FILE;
    private $maxEvents = 50;
    private $chatData; // instance of ChatData
 
    private function handleChatMessage($evt) {
        $this->lock();
 
        $data = @file_get_contents($this->filePath);
        $chatData = @unserialize($data);
 
        if(!is_object($chatData)) {
            $chatData = new ChatData();
        }
 
        if(is_object($evt)) {
            $events = $chatData->events;
 
            $nextId = $chatData->lastId + 1; // Assign new ID
            $evt->id = $nextId;
 
            $events[] = $evt; // Append new message to the list
 
            // Ensure that the message list does not grow infinitely
            if(count($events) > $this->maxEvents) {
                $events = array_slice($events, $this->maxEvents - count($events));
            }
 
            // Update chat data...
            $chatData->events = $events;
            $chatData->lastId = $nextId;
 
            // ... and save it back to the data file
            $data = serialize($chatData);
            file_put_contents($this->filePath, $data);
 
            $this->unlock();
        }
        $this->chatData = $chatData;
    }
 
    // Simple locking mechanism
    private $lock = null;
    private function lock() {
        if(!$this->lock) {
            $lock = fopen($this->filePath . ".lock", "w");
            if($lock) {
                flock($lock, LOCK_EX);
            }
            $this->lock = $lock;
        }
    }
 
    private function unlock() {
        fclose($this->lock);
        $this->lock = null;
    }
}
 
$server = new SoapServer("chat.wsdl");
$server->setObject(new ChatImpl());
$server->handle();
// The last PHP cosing tag is omitted intentionally

wsimport -s . "http://banavoz.com/chat-sample/server.php?wsdl"

package chatclient;
 
import java.util.Date;
import java.util.List;
 
import javax.xml.ws.Holder;
 
import com.banavoz.chat.Chat;
import com.banavoz.chat.ChatEvent;
import com.banavoz.chat.ChatMessage;
import com.banavoz.chat.Chat_Service;
 
public class Client {
    public static void main(String[] args) {
        try {
            Chat_Service service = new Chat_Service();
            Chat chat = service.getChatSOAP();
 
            ChatMessage msg = new ChatMessage();
            msg.setFrom("Java client");
            msg.setText("Hello from Java client, date=" + new Date());
 
            // This holder will hold event list from server:
            Holder<List<ChatEvent>> events = new Holder<List<ChatEvent>>();
            // Invoke the service:
            chat.send(msg, new Holder<String>(), events);
 
            for(ChatEvent e: events.value) {
                System.out.println("Message from " + e.getFrom() + ": " + e.getText());
            }
 
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}