在嵌入式 Jetty 上使用 javax.websocket 进行 JUnit 测试抛出 RejectedExecutionException : NonBlockingThread

Question

我正在尝试编写一个测试用例，它创建一个套接字并连接到嵌入式码头实例。我正在使用

• 码头:9.2.0.RC0
• javax.websocket-api 和 javax.websocket-client-api:1.0
• javax.websocket 服务器和客户端实现:9.1.5.v20140505

使用 websocket servlet 启动嵌入式 jetty 服务器似乎工作正常。我从 this example 获取了一些代码。然而这一行

...
container.connectToServer(SocketClient.class, uri);
...

抛出此异常

java.io.IOException: java.util.concurrent.RejectedExecutionException: org.eclipse.jetty.util.thread.NonBlockingThread@6f7476d
    at org.eclipse.jetty.websocket.client.WebSocketClient.initialiseClient(WebSocketClient.java:462)
    at org.eclipse.jetty.websocket.client.WebSocketClient.connect(WebSocketClient.java:187)
    at org.eclipse.jetty.websocket.jsr356.ClientContainer.connect(ClientContainer.java:135)
    at org.eclipse.jetty.websocket.jsr356.ClientContainer.connectToServer(ClientContainer.java:172)
    at com.playquickly.socket.SocketClient.connect(SocketClient.java:18)
    at com.playquickly.servlet.SocketServletTest.testSocket(SocketServletTest.java:50)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:48)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:67)
Caused by: java.util.concurrent.RejectedExecutionException: org.eclipse.jetty.util.thread.NonBlockingThread@6f7476d
    at org.eclipse.jetty.util.thread.QueuedThreadPool.execute(QueuedThreadPool.java:361)
    at org.eclipse.jetty.io.SelectorManager.execute(SelectorManager.java:122)
    at org.eclipse.jetty.io.SelectorManager.doStart(SelectorManager.java:207)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.websocket.client.io.ConnectionManager.doStart(ConnectionManager.java:200)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.websocket.client.WebSocketClient.initialiseClient(WebSocketClient.java:454)
    ... 30 more

这是我的包装，用于说明嵌入式码头服务器。

public class EmbeddedJetty {

    private final Logger LOG = Logger.getLogger(EmbeddedJetty.class.getSimpleName());

    private final int port;
    private Server server;

    public EmbeddedJetty(int port) {
        this.port = port;
    }

    public void start() throws Exception {
        server = new Server();
        ServerConnector connector = new ServerConnector(server);
        connector.setPort(8080);
        server.addConnector(connector);

        // Setup the basic application "context" for this application at "/"
        // This is also known as the handler tree (in jetty speak)
        ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
        context.setContextPath("/");
        server.setHandler(context);

        try {
            // Initialize javax.websocket layer
            ServerContainer wscontainer = WebSocketServerContainerInitializer.configureContext(context);

            // Add WebSocket endpoint to javax.websocket layer
            wscontainer.addEndpoint(SocketServlet.class);
            System.out.println("Begin start");
            server.start();
            System.out.println("End start");
        } catch (Throwable t) {
            t.printStackTrace(System.err);
        }
    }

    public void stop() throws Exception {
        server.stop();
        LOG.info("Jetty server stopped");
    }
}

客户端端点

@ClientEndpoint(encoders = {MessageCoder.class}, decoders = {MessageCoder.class})
public class SocketClient {

    public static Session connect(URI uri) throws Exception {
        WebSocketContainer container = ContainerProvider.getWebSocketContainer();

        try {
            // Attempt Connect
            return container.connectToServer(SocketClient.class, uri);
        } finally {
            // Force lifecycle stop when done with container.
            // This is to free up threads and resources that the
            // JSR-356 container allocates. But unfortunately
            // the JSR-356 spec does not handle lifecycles (yet)
            if (container instanceof LifeCycle) {
                ((LifeCycle) container).stop();
            }
        }
    }

    @OnMessage
    public void onMessage(Message msg, Session session) {
        System.out.println(session.getId() + ": " + msg.toString());
    }


}

还有测试

public class SocketServletTest {

    private static EmbeddedJetty server;

    @ClassRule
    public static final ExternalResource integrationServer = new ExternalResource() {
        @Override
        protected void before() throws Throwable {
            System.out.println("Starting...");
            server = new EmbeddedJetty(8080);
            server.start();
            System.out.println("Started");
        }
    };


    @Before
    public void setUp() throws Exception {

    }

    @After
    public void shutdown() throws Exception {
        server.stop();
    }

    @Test
    public void testSocket() throws Exception {
        URI uri = server.getWebsocketUri(SocketServlet.class);

        Session s1 = SocketClient.connect(uri);
    }

}

Answer 1

不要混合使用 Jetty 的版本。

这是 JSR-356 API 设计的一个不幸的副作用。 (客户端实现是根实现，服务器实现构建在其之上)

客户端容器按 JVM 初始化，每个服务器容器按 Web 应用程序初始化。

您的堆栈跟踪不是您指出的 Jetty 9.2.0.RC0(行号已关闭)

https://github.com/eclipse/jetty.project/blob/jetty-9.2.0.RC0/jetty-websocket/websocket-client/src/main/java/org/eclipse/jetty/websocket/client/io/ConnectionManager.java#L200

它们似乎来自 Jetty 9.1.5.v20140505

https://github.com/eclipse/jetty.project/blob/jetty-9.1.5.v20140505/jetty-websocket/websocket-client/src/main/java/org/eclipse/jetty/websocket/client/io/ConnectionManager.java#L200

到处使用 Jetty 9.2.2.v20140723。

此外，使用此版本意味着您可以摆脱finally container.stop() hack。