java.lang.NoClassDefFoundError error when GlassFish server receives a message

问题

Using eclipse mars and glass fish, I have made a local server. In the same package I have a class called MyClass.java. Every time, the server receives a message, I want the message to be processed by MyClass (and its methods). This is what I have:

package com.MT;

import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint("/serverendpointdemo")
public class ServerEndpointDemo {
    @OnOpen
    public void handleOpen () {
        System.out.println("JAVA: Client is now connected...");
    }

    @OnMessage
    public String handleMessage (String message) {
        System.out.println("JAVA: Received from client: "+ message);
        MyClass x = new MyClass();
        String replyMessage = x.someMethod(message);
        //System.out.println("JAVA: Send to Client ==> "+ replyMessage);
//      String replyMessage = "echo "+ message;
//      System.out.println("JAVA: Send to client: "+ replyMessage);
        return replyMessage;
    }

    @OnClose
    public void handleClose() {
        System.out.println("JAVA: Client is now disconnected...");
    }

    @OnError
    public void handleError (Throwable t) {
        t.printStackTrace();
    }


}

The problem is the compiler is giving me this message:

2015-10-26T22:36:37.088-0400|Severe: java.lang.NoClassDefFoundError: edu.someClass
    at com.MT.MyClass.(MedicalTranscriptRev4.java:35)
    at com.MT.ServerEndpointDemo.handleMessage(ServerEndpointDemo.java:20)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.glassfish.tyrus.core.AnnotatedEndpoint.callMethod(AnnotatedEndpoint.java:520)
    at org.glassfish.tyrus.core.AnnotatedEndpoint.access$100(AnnotatedEndpoint.java:87)
    at org.glassfish.tyrus.core.AnnotatedEndpoint$WholeHandler$1.onMessage(AnnotatedEndpoint.java:619)
    at org.glassfish.tyrus.core.TyrusSession.notifyMessageHandlers(TyrusSession.java:576)
    at org.glassfish.tyrus.core.TyrusEndpointWrapper.onMessage(TyrusEndpointWrapper.java:871)
    at org.glassfish.tyrus.core.TyrusWebSocket.onMessage(TyrusWebSocket.java:212)
    at org.glassfish.tyrus.core.frame.TextFrame.respond(TextFrame.java:139)
    at org.glassfish.tyrus.core.ProtocolHandler.process(ProtocolHandler.java:807)
    at org.glassfish.tyrus.core.TyrusWebSocketEngine$TyrusReadHandler.handle(TyrusWebSocketEngine.java:562)
    at org.glassfish.tyrus.servlet.TyrusHttpUpgradeHandler.onDataAvailable(TyrusHttpUpgradeHandler.java:173)
    at org.apache.catalina.connector.InputBuffer$ReadHandlerImpl.processDataAvailable(InputBuffer.java:488)
    at org.apache.catalina.connector.InputBuffer$ReadHandlerImpl.onDataAvailable(InputBuffer.java:453)
    at org.glassfish.grizzly.http.io.InputBuffer.invokeHandler(InputBuffer.java:1089)
    at org.glassfish.grizzly.http.io.InputBuffer.invokeHandlerOnProperThread(InputBuffer.java:1080)
    at org.glassfish.grizzly.http.io.InputBuffer.append(InputBuffer.java:963)
    at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:271)
    at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
    at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
    at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
    at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
    at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
    at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
    at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: edu.someClass
    at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1783)
    at org.glassfish.web.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1633)
    ... 36 more

I have made sure that edu.someClass which is a class in an external JAR file is in my class path. But its still not working. Any thought?

The thing is that MyClass needs to be compiled every time the server gets a new message? So I made a dummy class to test if it did compile every time and it did. But this dummy class did't have any JARs file (that is it had no import classes as compared to MyClass which does).

Here is the screen shot:

来源：https://stackoverflow.com/questions/33359207/java-lang-noclassdeffounderror-error-when-glassfish-server-receives-a-message