1.列表适配器
创建ChatViewHolder类继承于RecyclerView.ViewHolder
再建一个列表适配器继承于 RecyclerView.Adapter<ChatViewHolder>
除了显示自己发送消息外，还需要显示对方发送的消息，所以需要创建两个item布局文件
在ChatViewHolder中创建ViewHolder分别对应两个item，代码如下
sealed class ChatViewHolder(view: View) :RecyclerView.ViewHolder(view) {
class LeftViewHolder(view: View) : ChatViewHolder(view) {
val leftName: TextView = view.findViewById(R.id.message_left_name)
val leftMsg: TextView = view.findViewById(R.id.message_left_text)
val leftIcon: ImageView = view.findViewById(R.id.message_left_icon)
}
class RightViewHolder(view: View) : ChatViewHolder(view) {
val rightName: TextView = view.findViewById(R.id.message_right_name)
val rightMsg: TextView = view.findViewById(R.id.message_right_text)
val rightIcon: ImageView = view.findViewById(R.id.message_right_icon)
}
}列表适配器代码如下
class ChatAdapter : RecyclerView.Adapter<ChatViewHolder>() {
//消息数据
private var mList = mutableListOf<Msg>()
//在onCreateViewHolder中靠viewType来判断的，所以需要重写getItemViewType方法更改一下它的返回值
override fun getItemViewType(position: Int): Int {
return mList[position].type
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ChatViewHolder {
//判断viewType的值来返回ViewHolder
return if (viewType==1){
val view = LayoutInflater.from(parent.context).inflate(R.layout.item_message_left, parent, false)
ChatViewHolder.LeftViewHolder(view)
}else{
val view = LayoutInflater.from(parent.context).inflate(R.layout.item_message_right, parent, false)
ChatViewHolder.RightViewHolder(view)
}
}
override fun onBindViewHolder(holder: ChatViewHolder, position: Int) {
val current =mList[position]
when(holder){
is ChatViewHolder.LeftViewHolder->{
holder.leftName.text =current.name
holder.leftMsg.text =current.message
}
is ChatViewHolder.RightViewHolder->{
holder.rightName.text = current.name
holder.rightMsg.text = current.message
}
}
}
override fun getItemCount() =mList.size
fun addMessage(message:Msg){
mList.add(message)
notifyItemChanged(mList.indexOf(message))
}
}这里我们通过WebScoket来实现通讯的，所以还需要添加WebSocket的依赖
implementation "org.java-websocket:Java-WebSocket:1.4.0"2.消息接收和发送
创建一个新的Activity，并且接收从MainActivity传的用户名
val bundle = intent.getBundleExtra("data")
if (bundle==null){
Toast.makeText(this, "数据错误", Toast.LENGTH_SHORT).show()
finish()
}
userName =bundle!!.getString("username")!!
接收消息
val socket = object : MyWebSocket(URI.create(host)) {
override fun onOpen(handshakedata: ServerHandshake) {
Log.d("message","connected")
//当链接成功后发送第一条消息将用户名作为uid
send(userName)
}
override fun onMessage(message: String) {
//收到消息时，将消息添加到列表中
if (message.isEmpty()){
return
}
val json = JSONObject(message)
runOnUiThread {
//如果发送消息的用户是自己则不添加进列表
if (json.getString("username")!=userName){
mChatAdapter.addMessage(Msg(json.getString("username"),json.getString("message"),0))
}
}
}
}
try {
socket.connectBlocking()
} catch (e: InterruptedException) {
e.printStackTrace()
}消息发送，这里使用okhttp进行请求
val builder = Request.Builder()
val requestBody: RequestBody = FormBody.Builder()
.add("username", userName)
.add("message", message)
.build()
builder.url(pushUrl).post(requestBody)
mOkHttpClient.newCall(builder.build()).execute()message为用户发送消息的内容，pushURl为服务端消息推送url
服务端
这里使用GatewayWorker
下载demo(goto)， 将其解压，在GatewayWorker文件夹下(Applications同级)创建socket.php
<?php
require_once 'vendor/autoload.php';
use Workerman\Worker;
global $worker;
//监听12345端口，如果在服务器部署 需要放行该端口
$worker = new Worker('websocket://0.0.0.0:12345');
$worker->count = 1;
// worker进程启动后建立一个内部通讯端口
$worker->onWorkerStart = function($worker)
{
// 开启一个内部端口
$inner_text_worker = new Worker('Text://0.0.0.0:5678');
$inner_text_worker->onMessage = function($connection, $buffer)
{
global $worker;
// $data数组格式，里面有uid，表示向那个uid的页面推送数据
$data = json_decode($buffer, true);
$uid = $data['uid'];
//如果为all则向所有推送
if($uid =="all"){
$ret = broadcast(json_encode($data['percent']));
//返回结果
$connection->send($ret ? 'successful' : "fail");
}else{
$ret = broadcast(json_encode($data['percent']));
//返回结果
$connection->send($ret ? 'successful' : "fail");
}
};
$inner_text_worker->listen();
};
// 新增加一个属性，用来保存uid到connection的映射
$worker->uidConnections = array();
// 当有客户端发来消息时执行的回调函数
$worker->onMessage = function($connection, $data)use($worker)
{
// 判断当前客户端是否已经验证,既是否设置了uid
if(!isset($connection->uid))
{
// 没验证的话把第一个包当做uid（这里为了方便演示，没做真正的验证）
$connection->uid = $data;
$worker->uidConnections[$connection->uid] = $connection;
return;
}
};
// 当有客户端连接断开时
$worker->onClose = function($connection)use($worker)
{
global $worker;
if(isset($connection->uid))
{
// 连接断开时删除映射
unset($worker->uidConnections[$connection->uid]);
}
};
// 向所有验证的用户推送数据
function broadcast($message)
{
global $worker;
foreach($worker->uidConnections as $connection)
{
$connection->send($message);
}
}
// 针对uid推送数据
function sendMessageByUid($uid, $message)
{
global $worker;
if(isset($worker->uidConnections[$uid]))
{
$connection = $worker->uidConnections[$uid];
$connection->send($message);
return true;
}
return false;
}
// 运行worker
Worker::runAll();
push.php文件推送消息
if(isset($_POST['username']) && $_POST['message']){
// 建立socket连接到内部推送端口
$client = stream_socket_client('tcp://127.0.0.1:5678', $errno, $errmsg, 1);
$data = array('uid'=>'all', 'percent'=>array('username'=>$_POST['username']), 'message'=>$_POST['message']);
// 发送数据，注意5678端口是Text协议的端口，Text协议需要在数据末尾加上换行符
fwrite($client, json_encode($data)."\n");
// 读取推送结果
echo fread($client, 8192);
}socket.php需要使用命令启动
php socket.php start -d
webSocket url就是 ws://ip:port
pushUrl 为访问push.php的url
看看成品：
