Jetty之webSocket使用案例
Jetty
以前使用的tomcat，没接触过jetty，最近使用到jetty。jetty相对Tomcat，给我第一个使用感觉，那就是加载速度比tomcat快多了。而jetty还有一个最大的优点是tomcat不能达到的优势。
jetty倡导嵌入式开发，什么叫嵌入式开发呢？
与tomcat作个比较，tomcat相当于一个容器，我们需要把自己的web项目放入到tomcat指定目录中，在启动tomcat，这个时候我们的项目才能发布完成。而jetty，则不同，它相当于一个插件，我只要导入它所需要的依赖，调用他的api，我们的项目就能像tomcat那样支持http访问了。从这一点来说，他运行非常轻量级，也支持资源文件的管理。如果你想具体了解jetty，我建议应该去看看官方文档了。
使用Websocket
jetty使用的nio的技术，并且支持webSocket，而webSocket是基于tcp的一种最新的双工通信协议，用在IM领域比较多。具体写个demo，来看看怎么使用吧。
POM
<dependency>
<groupId>org.eclipse.jettygroupId>
<artifactId>jetty-serverartifactId>
<version>9.2.23.v20171218version>
dependency>
<dependency>
<groupId>org.eclipse.jettygroupId>
<artifactId>jetty-clientartifactId>
<version>9.2.23.v20171218version>
dependency>
<dependency>
<groupId>org.eclipse.jettygroupId>
<artifactId>jetty-servletsartifactId>
<version>9.2.23.v20171218version>
dependency>
<dependency>
<groupId>org.eclipse.jetty.websocketgroupId>
<artifactId>websocket-serverartifactId>
<version>9.2.23.v20171218version>
dependency>
<dependency>
<groupId>org.eclipse.jettygroupId>
<artifactId>jetty-webappartifactId>
<version>9.2.23.v20171218version>
dependency>
<dependency>
<groupId>org.eclipse.jettygroupId>
<artifactId>jetty-annotationsartifactId>
<version>9.2.23.v20171218version>
dependency>
我使用的是maven构建的项目，当然你可以到官方去下载，导入相应的依赖便可
WebSocketCreator实现webSocket
jetty的handler
public class WebSocketHandlerTest extends WebSocketHandler{
@Override
public void configure(WebSocketServletFactory webSocketServletFactory) {
webSocketServletFactory.getPolicy().setIdleTimeout(10L * 60L * 1000L);
webSocketServletFactory.getPolicy().setAsyncWriteTimeout(10L * 1000L);
/* 设置自定义的WebSocket组合 */
webSocketServletFactory.setCreator(new MyAdvancedEchoCreator());
}
}
WebSocketCreator
public class MyAdvancedEchoCreator implements org.eclipse.jetty.websocket.servlet.WebSocketCreator{
AnnotatedEchoSocket annotatedEchoSocket;
public MyAdvancedEchoCreator() {
annotatedEchoSocket = new AnnotatedEchoSocket();
}
@Override
public Object createWebSocket(ServletUpgradeRequest req, ServletUpgradeResponse resp) {
for (String sub : req.getSubProtocols())
{
/**
* 官方的Demo，这里可以根据相应的参数做判断，使用什么样的websocket
*/
}
// 没有有效的请求，忽略它
return annotatedEchoSocket;
}
}具体的webSocket
@WebSocket(maxTextMessageSize = 128 * 1024, maxBinaryMessageSize = 128 * 1024)
public class AnnotatedEchoSocket {
@OnWebSocketConnect
public void onText(Session session)throws Exception{
if(session.isOpen()){
//System.out.printf("返回消息 [%s]%n","ss");
session.getRemote().sendString("服务器发送数据： 测试001");
System.out.println("============================================");
Future fut;
fut = session.getRemote().sendStringByFuture("Hello");
try
{
fut.get(2, TimeUnit.SECONDS);
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
fut = session.getRemote().sendStringByFuture(df.format(new Date()));
fut.get(2, TimeUnit.SECONDS);
}
catch (InterruptedException | ExecutionException | TimeoutException e)
{
e.printStackTrace();
}
}
}
@OnWebSocketClose
public void onWebSocketBinary(int i,String string)
{
System.out.println("关闭");
}
@OnWebSocketMessage
public void onMessage(String msg)
{
System.out.println("服务器已经收到消息 " + msg);
System.out.printf("Got msg: %s%n",msg);
System.out.println();
}
public void onWebSocketBinary( org.eclipse.jetty.websocket.api.Session session, int a, java.lang.String s){
}
}
Server端
public static void main(String args[])
{
Server server = new Server(7778);
/* webSocket的handler */
WebSocketHandlerTest test = new WebSocketHandlerTest();
ContextHandler context = new ContextHandler();
/* 路径 */
context.setContextPath("/test");
context.setHandler(test);
server.setHandler(context);
try
{
/* 启动服务端 */
server.start();
server.join();
}
catch (Exception e)
{
e.printStackTrace();
}
}
WebClient测试
相应的服务端已经启动了，下面开始来客户端昨个测试，看看ok了没
public static void main(String args[])
{
String destUri = "ws://127.0.0.1:7778/test/";
if (args.length > 0)
{
destUri = args[0];
}
WebSocketClient client = new WebSocketClient();
SimpleEchoSocket socket = new SimpleEchoSocket();
try
{
client.start();
URI echoUri = new URI(destUri);
ClientUpgradeRequest request = new ClientUpgradeRequest();
request.setSubProtocols("c");
request.setHeader("index", "3");
/* 使用相应的webSocket进行连接 */
client.connect(socket, echoUri, request);
System.out.printf("Connecting to : %s%n", echoUri);
socket.awaitClose(1000, TimeUnit.SECONDS);
}
catch (Throwable t)
{
t.printStackTrace();
}
finally
{
try
{
client.stop();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}@WebSocket(maxTextMessageSize = 64 * 1024)
public class SimpleEchoSocket {
private final CountDownLatch closeLatch;
@SuppressWarnings("unused")
private Session session;
public SimpleEchoSocket()
{
this.closeLatch = new CountDownLatch(1);
}
public boolean awaitClose(int duration, TimeUnit unit) throws InterruptedException
{
return this.closeLatch.await(duration,unit);
}
@OnWebSocketClose
public void onClose(int statusCode, String reason)
{
System.out.printf("客户端关闭: %d - %s%n",statusCode,reason);
this.session = null;
this.closeLatch.countDown(); // 触发位置
}
@OnWebSocketConnect
public void onConnect(Session session)
{
System.out.printf("客户端连接: %s%n",session);
this.session = session;
try
{
Future fut;
System.out.println("客户端已经发送");
fut = session.getRemote().sendStringByFuture("11111Hello");
fut.get(2,TimeUnit.SECONDS); // 等待发送完成
fut = session.getRemote().sendStringByFuture("222222Thanks for the conversation.");
fut.get(2, TimeUnit.SECONDS); // 等待发送完成
System.out.println("客户端已经发送完成");
session.close(StatusCode.NORMAL,"I'm done");
}
catch (Throwable t)
{
t.printStackTrace();
}
}
@OnWebSocketMessage
public void onMessage(String msg)
{
System.out.printf("接收到服务器消息: %s%n",msg);
}
}
运行
总结
相应的webSocket一个测试小demo就完成了，虽然相应的例子比较少，官方文档又只有个别代码片段，新手入门比较难，但总算搭建完成，具体啊有其他的扩展还得去官方api查看了