Netty WebSocket长连接
## websocket客户端在线测试工具链接
注意点：websocket客户端在线测试工具，如你要测本机服务端的长连接，切记“ws://localhost:8888/ajaxchattest” 不要写本机的IP直接写localhost即可，另端口后面要加/ajaxchattest，否则总是报连接服务断开，我就是在此处踩了坑！！！
本人使用长连接的使用场景
业务场景：由于本人公司是做物业系统的，在业主的APP程序中创建访客信息，那么需求是则在物业平台系统中能自动弹出创建该访客的信息，所以前端WEB端要和后台服务端保存长链接，当访客添加信息后后台将此信息主动推给前端并展示！
Netty WebSocket Maven依赖
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty</artifactId>
<version>3.10.6.Final</version>
</dependency>
Netty WebSocket 后台 Java代码
以下代码就可以实现websocket长连接功能
webscoket初始化启动类
/**
* <desc>
* webscoket初始化启动类.
* </desc>
*
* @createDate 2018/7/19
*/
@RestController
public class WebsocketInitializationService {
@Autowired
WebSocketServer webSocketServer;
/**
* <desc>
* 初始化
* </desc>
*
* @author Juguang.S
* @createDate 2018/07/19
*/
@PostConstruct
public void polling() throws Exception {
webSocketServer.run();
}
}
websocket长连接服务类
参数：
PROPERTY_VISITOR_PUSH_MESSAGE_URL 为服务端所部署服务器的IP
PROPERTY_VISITOR_PUSH_MESSAGE_PORT 为服务端所部署服务器的端口
/**
* <desc>
* websocket长连接服务类.
* </desc>
*
* @createDate 2018/7/5
*/
@Service
public class WebSocketServer {
@Value("${" + PlatformConstants.PROPERTY_VISITOR_PUSH_MESSAGE_URL + "}")
private String PROPERTY_VISITOR_PUSH_MESSAGE_URL;
@Value("${" + PlatformConstants.PROPERTY_VISITOR_PUSH_MESSAGE_PORT + "}")
private String PROPERTY_VISITOR_PUSH_MESSAGE_PORT;
private static Logger LOG = Logger.getLogger(WebSocketServer.class);
static final boolean SSL = System.getProperty("ssl") != null;
public void run() throws Exception {
final SslContext sslCtx;
if (SSL) {
SelfSignedCertificate ssc = new SelfSignedCertificate();
sslCtx = SslContext.newServerContext(ssc.certificate(), ssc.privateKey());
} else {
sslCtx = null;
}
ServerBootstrap bootstrap = new ServerBootstrap(new NioServerSocketChannelFactory(
Executors.newCachedThreadPool(), Executors.newCachedThreadPool()));
bootstrap.setPipelineFactory(new WebSocketServerPipelineFactory(sslCtx));
bootstrap.bind(new InetSocketAddress(PROPERTY_VISITOR_PUSH_MESSAGE_URL, Integer.parseInt(PROPERTY_VISITOR_PUSH_MESSAGE_PORT)));
}
}
保存Channel对应类
/**
* <desc>
* 保存Channel对应类.
* </desc>
*
* @createDate 2018/7/5
*/
public class GatewayService {
private static Map<String, Channel> map = new ConcurrentHashMap<>();
public static void addGatewayChannel(String id, Channel gateway_channel){
map.put(id, gateway_channel);
}
public static Map<String, Channel> getChannels(){
return map;
}
public static Channel getGatewayChannel(String id){
return map.get(id);
}
public static void removeGatewayChannel(String id){
map.remove(id);
}
}
websocket中处理业务逻辑类
/**
* <desc>
* websocket中处理业务逻辑类.
* </desc>
*
* @createDate 2018/7/5
*/
public class WebSocketServerHandler extends SimpleChannelUpstreamHandler {
private static final String WEBSOCKET_PATH = "/websocket";
private WebSocketServerHandshaker handshaker;
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
Object msg = e.getMessage();
//传统的HTTP接入
if (msg instanceof HttpRequest) {
handleHttpRequest(ctx, (HttpRequest) msg);
}//WebSocket接入
else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
@Override
public void channelOpen(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception {
String uuid = ctx.getChannel().getId().toString();
GatewayService.addGatewayChannel(uuid, ctx.getChannel());
System.out.println(GatewayService.getGatewayChannel(uuid));
}
private void handleHttpRequest(ChannelHandlerContext ctx, HttpRequest req) {
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
if ("/".equals(req.getUri())) {
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, OK);
return;
}
if ("/favicon.ico".equals(req.getUri())) {
HttpResponse res = new DefaultHttpResponse(HTTP_1_1, NOT_FOUND);
sendHttpResponse(ctx, req, res);
return;
}
//构造握手响应返回，本机测试
WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
getWebSocketLocation(req), null, false);
handshaker = wsFactory.newHandshaker(req);
if (handshaker == null) {
wsFactory.sendUnsupportedWebSocketVersionResponse(ctx.getChannel());
} else {
handshaker.handshake(ctx.getChannel(), req).addListener(WebSocketServerHandshaker.HANDSHAKE_LISTENER);
}
}
private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
//判断是否关闭链路指令
if (frame instanceof CloseWebSocketFrame) {
handshaker.close(ctx.getChannel(), (CloseWebSocketFrame) frame);
return;
}
//判断是否是Ping消息
if (frame instanceof PingWebSocketFrame) {
ctx.getChannel().write(new PongWebSocketFrame(frame.getBinaryData()));
return;
}
//本例程仅支持文本信息，不支持二进制消息
if (!(frame instanceof TextWebSocketFrame)) {
throw new UnsupportedOperationException(
String.format("%s frame types not supported", frame.getClass().getName()));
}
//返回应答消息
String request = ((TextWebSocketFrame) frame).getText();
System.err.println(String.format("Channel %s received %s", ctx.getChannel().getId(), request));
// ctx.getChannel().write(new TextWebSocketFrame(request.toUpperCase()));
}
private static void sendHttpResponse(ChannelHandlerContext ctx, HttpRequest req, HttpResponse res) {
//返回应答给客户端
if (res.getStatus().getCode() != 200) {
res.setContent(ChannelBuffers.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8));
setContentLength(res, res.getContent().readableBytes());
}
//如果是非Keep-Alive，关闭连接
ChannelFuture f = ctx.getChannel().write(res);
if (!isKeepAlive(req) || res.getStatus().getCode() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
e.getCause().printStackTrace();
e.getChannel().close();
}
private static String getWebSocketLocation(HttpRequest req) {
String location = req.headers().get(HOST) + WEBSOCKET_PATH;
if (WebSocketServer.SSL) {
return "wss://" + location;
} else {
return "ws://" + location;
}
}
}
WebSocketServerPipelineFactory类
/**
* <desc>
* WebSocketServerPipelineFactory类.
* </desc>
*
* @createDate 2018/7/5
*/
public class WebSocketServerPipelineFactory implements ChannelPipelineFactory {
private final SslContext sslCtx;
public WebSocketServerPipelineFactory(SslContext sslCtx) {
this.sslCtx = sslCtx;
}
public ChannelPipeline getPipeline() {
ChannelPipeline pipeline = Channels.pipeline();
if (sslCtx != null) {
pipeline.addLast("ssl", sslCtx.newHandler());
}
pipeline.addLast("decoder", new HttpRequestDecoder());
pipeline.addLast("aggregator", new HttpChunkAggregator(65536));
pipeline.addLast("encoder", new HttpResponseEncoder());
pipeline.addLast("handler", new WebSocketServerHandler());
return pipeline;
}
}
推送业务逻辑触发类
/**
* <desc>
* App用户添加访客后主动向前端推送消息
* </desc>
* @return
* @createDate 2018/07/13
*/
@Override
@Transactional(rollbackFor = Exception.class,propagation = Propagation.REQUIRED)
public void visitorPushMessage() throws Exception {
System.out.println("task is beginning...");
LOG.info("【定时任务】定时刷新访客表获取未推送的APP新增访客信息task is beginning...");
try{
Map<String, Channel> map = GatewayService.getChannels();
Iterator<String> it = map.keySet().iterator();
List<String> passId = new ArrayList<>();
while (it.hasNext()) {
String key = it.next();
Channel obj = map.get(key);
System.out.println("channel id is: " + key);
LOG.info("【定时任务】定时刷新访客表获取未推送的APP新增访客信息channel id is: " + key);
List<PropertyVisitorInfoByPushVO> infoByPushVOSList = iVisitorPushMessageDao.getVisitorInfoByPush();
if(!obj.isOpen() || !obj.isConnected()){
GatewayService.removeGatewayChannel(key);
}
if(infoByPushVOSList!=null && infoByPushVOSList.size()>0){
String strUTF8 = URLDecoder.decode(JSON.toJSONString(infoByPushVOSList), "UTF-8");
System.out.println("strUTF8:"+strUTF8);
if(obj.isOpen()){
obj.write(new TextWebSocketFrame(strUTF8));
for(PropertyVisitorInfoByPushVO pushVO : infoByPushVOSList){
passId.add(pushVO.getPassId());
}
}else{
GatewayService.removeGatewayChannel(key);
}
}
}
if(passId.size()>0){
iVisitorPushMessageDao.updatePushStatus(passId.toArray(new String[passId.size()]));
LOG.info("【定时任务】定时刷新访客表获取未推送的APP新增访客信息传送给客户端修改状态已完毕");
System.err.println("传送给客户端修改状态已完毕");
}
}catch(Exception e){throw e;}
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}