public void handle(String target, Request baseRequest, HttpServletRequest request, HttpServletResponse response)    throws IOException, ServletException

Request base_request = request instanceof Request ? (Request)request : HttpConnection.getCurrentConnection().getHttpChannel().getRequest();Response base_response = response instanceof Response ? (Response)response : HttpConnection.getCurrentConnection().getHttpChannel().getResponse();

 response.setContentType("text/html"); response.setStatus(HttpServletResponse.SC_OK); response.getWriter().println("<h1>Hello OneHandler</h1>");

 Request base_request = (request instanceof Request) ? (Request)request:HttpConnection.getCurrentConnection().getHttpChannel().getRequest(); base_request.setHandled(true);

try {    base_request.setSession(a_session);    next_handler.handle(target,request,response,dispatch); } finally {    base_request.setSession(old_session); }

+提示

　　　　这个例子默认你将web应用部署到Jetty标准安装包中。

$ java -Xdebug -agentlib:jdwp=transport=dt_socket,address=9999,server=y,suspend=n -jar start.jar

#===========================================================# Configure JVM arguments.# If JVM args are include in an ini file then --exec is needed# to start a new JVM from start.jar with the extra args.# If you wish to avoid an extra JVM running, place JVM args# on the normal command line and do not use --exec#-------------------------------------------------------------exec-Xdebug-agentlib:jdwp=transport=dt_socket,address=9999,server=y,suspend=n# -Xmx2000m# -Xmn512m# -XX:+UseConcMarkSweepGC# -XX:ParallelCMSThreads=2# -XX:+CMSClassUnloadingEnabled# -XX:+UseCMSCompactAtFullCollection# -XX:CMSInitiatingOccupancyFraction=80# -verbose:gc# -XX:+PrintGCDateStamps# -XX:+PrintGCTimeStamps# -XX:+PrintGCDetails# -XX:+PrintTenuringDistribution# -XX:+PrintCommandLineFlags# -XX:+DisableExplicitGC

Listening for transport dt_socket at address: 9999

+技巧

　　　　你可以通过jetty-logging.properties文件来对Jetty的日志进行配置。如果这个文件在classpath中，那么Jetty启动时将会应用这个文件来对日志进行配置，我们使用这种扩展方法来使Jetty的开发变得异常简单。

+技巧

　　　　你可以通过jetty-logging.properties文件来对Jetty的日志进行配置。如果这个文件在classpath中，那么Jetty启动时将会应用这个文件来对日志进行配置，我们使用这种扩展方法来使Jetty的开发变得异常简单。

+重要

　　　　早期WebSocket 仅被Jetty7和Jetty8支持，但是Jetty9已经不再支持。这意味着Jetty9将不再支持实现旧版本WebSocket 的一些老的浏览器

+技巧

　　　　如果你想知道你选择的浏览器是否支持WebSocket，可以访问 caniuse.com/websockets

WebAppContext context = new WebAppContext();context.setAttribute("org.eclipse.jetty.containerInitializerExclusionPattern",                     "org.eclipse.jetty.websocket.jsr356.server.deploy.WebSocketServerContainerInitializer|com.acme.*");

if(session.isOpen()) {  // 发送消息}

if(session.isSecure()) {  // 使用‘wss://‘进行连接}

UpgradeRequest req = session.getUpgradeRequest();String channelName = req.getParameterMap().get("channelName");UpgradeRespons resp = session.getUpgradeResponse();String subprotocol = resp.getAcceptedSubProtocol();

InetSocketAddress remoteAddr = session.getRemoteAddress();

session.setIdleTimeout(2000); // 2 秒超时时间

RemoteEndpoint remote = session.getRemote();// 堵塞式发送二进制消息到远程终端ByteBuffer buf = ByteBuffer.wrap(new byte[] { 0x11, 0x22, 0x33, 0x44 });try{    remote.sendBytes(buf);}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 阻塞式发送文件到远程终端try{    remote.sendString("Hello World");}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 阻塞发送二进制到远程终端// 部分一ByteBuffer buf1 = ByteBuffer.wrap(new byte[] { 0x11, 0x22 });// 部分二 (最后一个部分)ByteBuffer buf2 = ByteBuffer.wrap(new byte[] { 0x33, 0x44 });try{    remote.sendPartialBytes(buf1,false);    remote.sendPartialBytes(buf2,true); // isLast is true}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 堵塞式发送文本到远程终端String part1 = "Hello";String part2 = " World";try{    remote.sendPartialString(part1,false);    remote.sendPartialString(part2,true); // 最后一个部分}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 阻塞发送PING控制帧String data = "http://www.mamicode.com/You There?";ByteBuffer payload = ByteBuffer.wrap(data.getBytes());try{    remote.sendPing(payload);}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 阻塞式发送PONG到终端String data = "http://www.mamicode.com/Yup, I‘m here";ByteBuffer payload = ByteBuffer.wrap(data.getBytes());try{    remote.sendPong(payload);}catch (IOException e){    e.printStackTrace(System.err);}

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端ByteBuffer buf = ByteBuffer.wrap(new byte[] { 0x11, 0x22, 0x33, 0x44 });remote.sendBytesByFuture(buf);

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端ByteBuffer buf = ByteBuffer.wrap(new byte[] { 0x11, 0x22, 0x33, 0x44 });try{    Future<Void> fut = remote.sendBytesByFuture(buf);    // 等待完成（永久）    fut.get();}catch (ExecutionException | InterruptedException e){    // 发送失败    e.printStackTrace();}

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端ByteBuffer buf = ByteBuffer.wrap(new byte[] { 0x11, 0x22, 0x33, 0x44 });Future<Void> fut = null;try{    fut = remote.sendBytesByFuture(buf);    // 等待完成（有超时时间）    fut.get(2,TimeUnit.SECONDS);}catch (ExecutionException | InterruptedException e){    // 发送失败    e.printStackTrace();}catch (TimeoutException e){    // 发送超时    e.printStackTrace();    if (fut != null)    {        // 取消消息发送        fut.cancel(true);    }}

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端remote.sendStringByFuture("Hello World");

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端try{    Future<Void> fut = remote.sendStringByFuture("Hello World");    // 等待完成（永久）    fut.get();}catch (ExecutionException | InterruptedException e){    // 发送失败    e.printStackTrace();}

RemoteEndpoint remote = session.getRemote();// 异步发送二进制到远程终端Future<Void> fut = null;try{    fut = remote.sendStringByFuture("Hello World");    // 等待完成（有超时时间）    fut.get(2,TimeUnit.SECONDS);}catch (ExecutionException | InterruptedException e){    // 发送失败    e.printStackTrace();}catch (TimeoutException e){    // 发送超时    e.printStackTrace();    if (fut != null)    {        // 取消消息发送        fut.cancel(true);    }}

package examples.echo;import org.eclipse.jetty.websocket.api.Session;import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;import org.eclipse.jetty.websocket.api.annotations.WebSocket;/** * 使用注解示例 */@WebSocket(maxTextMessageSize = 64 * 1024)public class AnnotatedEchoSocket{    @OnWebSocketMessage    public void onText(Session session, String message)    {        if (session.isOpen())        {            System.out.printf("Echoing back message [%s]%n",message);            // echo the message back            session.getRemote().sendString(message,null);        }    }}

package examples.echo;import org.eclipse.jetty.websocket.api.Session;import org.eclipse.jetty.websocket.api.WebSocketListener;/** * 使用监听器的示例 */public class ListenerEchoSocket implements WebSocketListener{    private Session outbound;    @Override    public void onWebSocketBinary(byte[] payload, int offset, int len)    {        /* 只对文本消息感兴趣 */    }    @Override    public void onWebSocketClose(int statusCode, String reason)    {        this.outbound = null;    }    @Override    public void onWebSocketConnect(Session session)    {        this.outbound = session;    }    @Override    public void onWebSocketError(Throwable cause)    {        cause.printStackTrace(System.err);    }    @Override    public void onWebSocketText(String message)    {        if ((outbound != null) && (outbound.isOpen()))        {            System.out.printf("Echoing back message [%s]%n",message);            // 监听到消息返回            outbound.getRemote().sendString(message,null);        }    }}

package examples.echo;import java.io.IOException;import org.eclipse.jetty.websocket.api.WebSocketAdapter;/** * 使用适配器的例子 */public class AdapterEchoSocket extends WebSocketAdapter{    @Override    public void onWebSocketText(String message)    {        if (isConnected())        {            try            {                System.out.printf("Echoing back message [%s]%n",message);                // 将接收到的消息返回                getRemote().sendString(message);            }            catch (IOException e)            {                e.printStackTrace(System.err);            }        }    }}

package examples;import javax.servlet.annotation.WebServlet;import org.eclipse.jetty.websocket.servlet.WebSocketServlet;import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;@SuppressWarnings("serial")@WebServlet(name = "MyEcho WebSocket Servlet", urlPatterns = { "/echo" })public class MyEchoServlet extends WebSocketServlet{    @Override    public void configure(WebSocketServletFactory factory)    {        // 设置10秒超时时间        factory.getPolicy().setIdleTimeout(10000);        // 将MyEchoSocket 注册成一个要升级的WebSocket         factory.register(MyEchoSocket.class);    }}

+提示

　　　　当配置websockets时，考虑防火墙和路由器的超时时间是很重要的。确保websocket 的超时时间低于你的防火墙或者路由器。

package examples;import org.eclipse.jetty.websocket.servlet.ServletUpgradeRequest;import org.eclipse.jetty.websocket.servlet.ServletUpgradeResponse;import org.eclipse.jetty.websocket.servlet.WebSocketCreator;public class MyAdvancedEchoCreator implements WebSocketCreator{    private MyBinaryEchoSocket binaryEcho;    private MyEchoSocket textEcho;    public MyAdvancedEchoCreator()    {        // 创建可重用的套接字        this.binaryEcho = new MyBinaryEchoSocket();        this.textEcho = new MyEchoSocket();    }    @Override    public Object createWebSocket(ServletUpgradeRequest req, ServletUpgradeResponse resp)    {        for (String subprotocol : req.getSubProtocols())        {            if ("binary".equals(subprotocol))            {                resp.setAcceptedSubProtocol(subprotocol);                return binaryEcho;            }            if ("text".equals(subprotocol))            {                resp.setAcceptedSubProtocol(subprotocol);                return textEcho;            }        }        // 没有有效的请求，忽略它        return null;    }}

package examples;import javax.servlet.annotation.WebServlet;import org.eclipse.jetty.websocket.servlet.WebSocketServlet;import org.eclipse.jetty.websocket.servlet.WebSocketServletFactory;@SuppressWarnings("serial")@WebServlet(name = "MyAdvanced Echo WebSocket Servlet", urlPatterns = { "/advecho" })public class MyAdvancedEchoServlet extends WebSocketServlet{    @Override    public void configure(WebSocketServletFactory factory)    {        // 设置10秒超时时间        factory.getPolicy().setIdleTimeout(10000);        // 设置一个普通的创建者        factory.setCreator(new MyAdvancedEchoCreator());    }}

<dependency>
　　<groupId>org.eclipse.jetty.websocket</groupId>
　　<artifactId>websocket-client</artifactId>
　　<version>${project.version}</version>
</dependency>

package examples;import java.net.URI;import java.util.concurrent.TimeUnit;import org.eclipse.jetty.websocket.client.ClientUpgradeRequest;import org.eclipse.jetty.websocket.client.WebSocketClient;/** * 一个简单的客户端例子 */public class SimpleEchoClient{    public static void main(String[] args)    {        String destUri = "ws://echo.websocket.org";        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();            client.connect(socket,echoUri,request);            System.out.printf("Connecting to : %s%n",echoUri);            // 等待关闭的socket 连接            socket.awaitClose(5,TimeUnit.SECONDS);        }        catch (Throwable t)        {            t.printStackTrace();        }        finally        {            try            {                client.stop();            }            catch (Exception e)            {                e.printStackTrace();            }        }    }}

package examples;import java.util.concurrent.CountDownLatch;import java.util.concurrent.Future;import java.util.concurrent.TimeUnit;import org.eclipse.jetty.websocket.api.Session;import org.eclipse.jetty.websocket.api.StatusCode;import org.eclipse.jetty.websocket.api.annotations.OnWebSocketClose;import org.eclipse.jetty.websocket.api.annotations.OnWebSocketConnect;import org.eclipse.jetty.websocket.api.annotations.OnWebSocketMessage;import org.eclipse.jetty.websocket.api.annotations.WebSocket;/** * Socket的基本例子 */@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("Connection closed: %d - %s%n",statusCode,reason);        this.session = null;        this.closeLatch.countDown(); // 触发位置    }    @OnWebSocketConnect    public void onConnect(Session session)    {        System.out.printf("Got connect: %s%n",session);        this.session = session;        try        {            Future<Void> fut;            fut = session.getRemote().sendStringByFuture("Hello");            fut.get(2,TimeUnit.SECONDS); // 等待发送完成            fut = session.getRemote().sendStringByFuture("Thanks for the conversation.");            fut.get(2,TimeUnit.SECONDS); // 等待发送完成            session.close(StatusCode.NORMAL,"I‘m done");        }        catch (Throwable t)        {            t.printStackTrace();        }    }    @OnWebSocketMessage    public void onMessage(String msg)    {        System.out.printf("Got msg: %s%n",msg);    }}

附言：

　　　　Jetty文档的目录详见：http://www.cnblogs.com/yiwangzhibujian/p/5832294.html

　　　　Jetty第一章翻译详见：http://www.cnblogs.com/yiwangzhibujian/p/5832597.html

　　　　Jetty第四章（21-22）详见：http://www.cnblogs.com/yiwangzhibujian/p/5845623.html

　　　　Jetty第四章（23）详见：http://www.cnblogs.com/yiwangzhibujian/p/5856857.html

　　　　这次翻译的是第四部分的第24到27小节。翻译的过程中觉得Jetty的参考文档写的并不是特别好，偏向于理论，而且还有很多地方等待完善，虽然也有很多示例代码，但是都是一些代码片段，不太适合入门使用，所以我也打算在翻译快结束的时候，根据自己的理解写几篇用于实践的项目例子。