[jetty-users] Handler not found for embedded jetty

[David P <davidswalkabout@xxxxxxxxx>]

I want to use jetty to receive json POSTs, and use the values to call setters in another class that's part of a service.

Tests using curl return a 404, and dumping at jetty start reveals no routes from query paths to handlers. This seems to be the relevant section of the dump:

 += ServerConnector@25b485ba{HTTP/1.1,[http/1.1]}{0.0.0.0:8081} - STARTED
 |   +~ org.eclipse.jetty.server.Server@731f8236 - STARTING
 |   +~ qtp1113619023{STARTED,6<=6<=6,i=1,q=0} - STARTED
 |   += org.eclipse.jetty.util.thread.ScheduledExecutorScheduler@1188e820 - STARTED
 |   +- org.eclipse.jetty.io.ArrayByteBufferPool@240237d2
 |   += HttpConnectionFactory@33b37288[HTTP/1.1] - STARTED
 |   |   +- HttpConfiguration@25a65b77{32768/8192,8192/8192,https://:0,[]}
 |   += org.eclipse.jetty.server.ServerConnector$ServerConnectorManager@2ed0fbae - STARTED
 |   |   += org.eclipse.jetty.io.ManagedSelector@212bf671 id=0 keys=0 selected=0 id=0
 |   |   |   +- sun.nio.ch.EPollSelectorImpl@6298dace keys=0
 |   |   += org.eclipse.jetty.io.ManagedSelector@2aece37d id=1 keys=0 selected=0 id=1
 |   |       +- sun.nio.ch.EPollSelectorImpl@43668d89 keys=0
 |   +- sun.nio.ch.ServerSocketChannelImpl[/0:0:0:0:0:0:0:0:8081]
 |   +- qtp1113619023-24-acceptor-0@1b83efaf-ServerConnector@25b485ba{HTTP/1.1,[http/1.1]}{0.0.0.0:8081}
 
I've tried switching my context path and query path. How should I change my code so it handles a request like this?

    curl -d '{"name1":"value1", "name2":"value2"}' -H "Content-Type: application/json" -X POST http://localhost:8081/metadataForUtterance

Here's the code:

    //Adapted from https://www.baeldung.com/jetty-embedded
    // https://github.com/eugenp/tutorials/blob/master/libraries-server/src/main/java/com/baeldung/jetty/JettyServer.java

    import org.apache.log4j.Logger;
    import org.eclipse.jetty.server.Connector;
    import org.eclipse.jetty.server.Server;
    import org.eclipse.jetty.server.ServerConnector;
    import org.eclipse.jetty.servlet.ServletContextHandler;
    import org.eclipse.jetty.servlet.ServletHolder;
    import org.eclipse.jetty.util.thread.QueuedThreadPool;

    class JettyServer {
        private static final Logger s_oLogger = Logger.getLogger(JettyServer.class);

        private static final String s_sContextPath = "/";
        private static final String s_sQueryPath = "/metadataForUtterance";
        private static final int s_iPort = 8081;
        //When the two values below were both set to 1, the service log revealed:
        // java.lang.IllegalStateException: Insufficient threads: max=1 < needed(acceptors=1 + selectors=4 + request=1)
        private static final int s_iMaxThreads = 6;
        private static final int s_iMinThreads = 6;
        private static final int s_iMsecsIdleTimeout = 120;

        private Server _oServer;

        void start(MyFriendClass oFriendNeedingMetadata)
        throws Exception
        {
            QueuedThreadPool oThreadPool
                    = new QueuedThreadPool(
                            s_iMaxThreads,
                            s_iMinThreads,
                            s_iMsecsIdleTimeout
                    );

            _oServer = new Server( oThreadPool );

            //DEBUG
            // See https://www.eclipse.org/jetty/documentation/current/jetty-dump-tool.html
            oThreadPool.setDetailedDump(true);
            _oServer.setDumpAfterStart(true);

            ServerConnector oConnector = new ServerConnector( _oServer );
            oConnector.setPort( s_iPort );
            _oServer.setConnectors( new Connector[] { oConnector } );

            //Adapted from https://stackoverflow.com/a/39440430/6856046
            // in order to pass oFriendNeedingMetadata to the UtteranceMetadataFromPost instance.
            ServletContextHandler oContext = new ServletContextHandler();
            oContext.setContextPath( s_sContextPath );
            UtteranceMetadataFromPost oServletForMetadataPosts
                    = new UtteranceMetadataFromPost( oFriendNeedingMetadata );
            ServletHolder oServletHolder = new ServletHolder(oServletForMetadataPosts);
            oContext.addServlet(
                oServletHolder,
                s_sQueryPath
            );

            _oServer.start();

            s_oLogger.debug(
                "Started: s_sContextPath["+ s_sContextPath
                +"] s_iPort["+ s_iPort
                +"] s_sQueryPath["+ s_sQueryPath
                +"] s_iMaxThreads["+ s_iMaxThreads
                +"] s_iMinThreads["+ s_iMinThreads
                +"] s_iMsecsIdleTimeout["+ s_iMsecsIdleTimeout
                +"]."
            );
        }

        void stop() throws Exception {
            _oServer.stop();
        }
    }

Cheers,
David

Btw, I also tried following https://www.eclipse.org/jetty/documentation/current/advanced-embedding.html One problem there is that the uber jar is only ~500kB and seems corrupted every time I download it:

    curl -o jetty-all-uber.jar https://repo1.maven.org/maven2/org/eclipse/jetty/aggregate/jetty-all/9.4.18.v20190429/jetty-all-9.4.18.v20190429-uber.jar