在编写代码过程中,我们将使用 WebSocket 和 PHP 套接字编程创建一个简单的聊天应用程序,WebSocket 用于创建从 PHP 聊天服务器发送或接收消息的桥接器。
在 web 世界中,我们一般使用 HTTP 请求的方式来进行客户端和服务器端的通信。在这个聊天示例中,我们使用套接字与服务器进行通信。
为了在客户端和服务器之间建立套接字连接,我们使用 WebSocket协议 (ws://) 来指定处理 WebSocket 握手的 PHP 页面的地址。
创建 WebSocket 后,有回调来处理在聊天过程中客户端和服务器之间发生的事件。
创建 WebSocket 和回调事件处理程序
以下脚本用于在客户端创建 WebSocket 并定义回调处理程序来处理不同的聊天事件,比如处理:连接状态、聊天信息和错误信息(存在情况下出现)。
聊天消息以 JSON 格式编码,并在提交时发送到服务器。
编码数据将在 PHP 端点中解码以创建聊天框消息实例,除了 JSON 编码解码之外,PHP 还大量支持以编程方式处理 JSON 数据以进行读写分析等。
JS脚本
function showMessage(messageHTML) {
$('#chat-box').append(messageHTML);
}
$(document).ready(function(){
var websocket = new WebSocket("ws://localhost:8090/songco/chat.php");
websocket.onopen = function(event) {
showMessage("<div class='chat-connection-ack'>连接已建立!</div>");
}
websocket.onmessage = function(event) {
var Data = JSON.parse(event.data);
showMessage("<div class='"+Data.message_type+"'>"+Data.message+"</div>");
$('#chat-message').val('');
};
websocket.onerror = function(event){
showMessage("<div class='error'>由于某些错误而导致的问题</div>");
};
websocket.onclose = function(event){
showMessage("<div class='chat-connection-ack'>连接已关闭</div>");
};
$('#frmChat').on("submit",function(event){
event.preventDefault();
$('#chat-user').attr("type","hidden");
var messageJSON = {
chat_user: $('#chat-user').val(),
chat_message: $('#chat-message').val()
};
websocket.send(JSON.stringify(messageJSON));
});
});
聊天应用程序的 PHP 套接字编程
此 PHP 代码检查新的套接字连接请求。如果找到任何新的连接请求,那么它将接受并执行与新套接字资源的握手。
然后,它通过密封编码的确认消息向客户端发送有关连接的确认。
它接收通过现有连接发送的套接字数据,并对其进行解封和解码以捆绑接收到的数据并将其发送到聊天客户端,握手、密封、开封、发送功能是通过使用 ChatHandler 类来处理的。
PHP代码
define('HOST_NAME',"localhost");
define('PORT',"8090");
$null = NULL;
require_once("class.chathandler.php");
$chatHandler = new ChatHandler();
$socketResource = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
socket_set_option($socketResource, SOL_SOCKET, SO_REUSEADDR, 1);
socket_bind($socketResource, 0, PORT);
socket_listen($socketResource);
$clientSocketArray = array($socketResource);
while (true) {
$newSocketArray = $clientSocketArray;
socket_select($newSocketArray, $null, $null, 0, 10);
if (in_array($socketResource, $newSocketArray)) {
$newSocket = socket_accept($socketResource);
$clientSocketArray[] = $newSocket;
$header = socket_read($newSocket, 1024);
$chatHandler->doHandshake($header, $newSocket, HOST_NAME, PORT);
socket_getpeername($newSocket, $client_ip_address);
$connectionACK = $chatHandler->newConnectionACK($client_ip_address);
$chatHandler->send($connectionACK);
$newSocketIndex = array_search($socketResource, $newSocketArray);
unset($newSocketArray[$newSocketIndex]);
}
foreach ($newSocketArray as $newSocketArrayResource) {
while(socket_recv($newSocketArrayResource, $socketData, 1024, 0) >= 1){
$socketMessage = $chatHandler->unseal($socketData);
$messageObj = json_decode($socketMessage);
$chat_box_message = $chatHandler->createChatBoxMessage($messageObj->chat_user, $messageObj->chat_message);
$chatHandler->send($chat_box_message);
break 2;
}
$socketData = @socket_read($newSocketArrayResource, 1024, PHP_NORMAL_READ);
if ($socketData === false) {
socket_getpeername($newSocketArrayResource, $client_ip_address);
$connectionACK = $chatHandler->connectionDisconnectACK($client_ip_address);
$chatHandler->send($connectionACK);
$newSocketIndex = array_search($newSocketArrayResource, $clientSocketArray);
unset($clientSocketArray[$newSocketIndex]);
}
}
}
socket_close($socketResource);
聊天处理程序类是
PHP代码
class ChatHandler {
function send($message) {
global $clientSocketArray;
$messageLength = strlen($message);
foreach($clientSocketArray as $clientSocket)
{
@socket_write($clientSocket,$message,$messageLength);
}
return true;
}
function unseal($socketData) {
$length = ord($socketData[1]) & 127;
if($length == 126) {
$masks = substr($socketData, 4, 4);
$data = substr($socketData, 8);
}
elseif($length == 127) {
$masks = substr($socketData, 10, 4);
$data = substr($socketData, 14);
}
else {
$masks = substr($socketData, 2, 4);
$data = substr($socketData, 6);
}
$socketData = "";
for ($i = 0; $i < strlen($data); ++$i) {
$socketData .= $data[$i] ^ $masks[$i%4];
}
return $socketData;
}
function seal($socketData) {
$b1 = 0x80 | (0x1 & 0x0f);
$length = strlen($socketData);
if($length <= 125)
$header = pack('CC', $b1, $length);
elseif($length > 125 && $length < 65536)
$header = pack('CCn', $b1, 126, $length);
elseif($length >= 65536)
$header = pack('CCNN', $b1, 127, $length);
return $header.$socketData;
}
function doHandshake($received_header,$client_socket_resource, $host_name, $port) {
$headers = array();
$lines = preg_split("/\r\n/", $received_header);
foreach($lines as $line)
{
$line = chop($line);
if(preg_match('/\A(\S+): (.*)\z/', $line, $matches))
{
$headers[$matches[1]] = $matches[2];
}
}
$secKey = $headers['Sec-WebSocket-Key'];
$secAccept = base64_encode(pack('H*', sha1($secKey . '258EAFA5-E914-47DA-95CA-C5AB0DC85B11')));
$buffer = "HTTP/1.1 101 Web套接字协议握手\r\n" .
"Upgrade: websocket\r\n" .
"Connection: Upgrade\r\n" .
"WebSocket-Origin: $host_name\r\n" .
"WebSocket-Location: ws://$host_name:$port/demo/shout.php\r\n".
"Sec-WebSocket-Accept:$secAccept\r\n\r\n";
socket_write($client_socket_resource,$buffer,strlen($buffer));
}
function newConnectionACK($client_ip_address) {
$message = 'New client ' . $client_ip_address.' joined';
$messageArray = array('message'=>$message,'message_type'=>'chat-connection-ack');
$ACK = $this->seal(json_encode($messageArray));
return $ACK;
}
function connectionDisconnectACK($client_ip_address) {
$message = 'Client ' . $client_ip_address.' disconnected';
$messageArray = array('message'=>$message,'message_type'=>'chat-connection-ack');
$ACK = $this->seal(json_encode($messageArray));
return $ACK;
}
function createChatBoxMessage($chat_user,$chat_box_message) {
$message = $chat_user . ": <div class='chat-box-message'>" . $chat_box_message . "</div>";
$messageArray = array('message'=>$message,'message_type'=>'chat-box-html');
$chatMessage = $this->seal(json_encode($messageArray));
return $chatMessage;
}
}
使用命令行建立连接
下图显示了使用此应用程序建立连接以开始聊天的命令行屏幕。