Using RMI with JSF and Tomcat

Question

I want to write a simple application using RMI. On the server side I have an interface foo and a class fooImpl. My interface is:

import java.rmi.Remote;

public interface Foo extends Remote {
   public String exec(String test) throws Exception;
}

My implementation of the the above interface is:

import java.rmi.server.UnicastRemoteObject;

public class FooImpl extends UnicastRemoteObject implements Foo {

    public FooImpl() throws Exception {
        java.rmi.registry.LocateRegistry.createRegistry(1099);
        java.rmi.Naming.rebind("myFoo",this);
    }

    public String exec(String test) {
        return "This is a Test";
    }

    public static void main(String[] args) {
        try {
            FooImpl fooImpl = new FooImpl();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

On the client side, I have web application using PrimeFace which is runnig on Tomcat. There is a IndexBean on client side:

import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import java.net.MalformedURLException;
import java.rmi.NotBoundException;
import java.rmi.RemoteException;

@ManagedBean
@RequestScoped
public class IndexBean {

    public void execute() {
        try {
            Foo foo = (Foo) java.rmi.Naming.lookup("//localhost/myFoo");
            System.out.println(foo.exec());
        } catch (NotBoundException e) {
            e.printStackTrace();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (RemoteException e) {
            e.printStackTrace();
        }
    }

}

when I execute the code, I get the following error at the client side:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: java.lang.ClassNotFoundException: Foo (no security manager: RMI class loader disabled) at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source) at java.rmi.Naming.lookup(Naming.java:101) at bean.IndexBean.execute(IndexBean.java:15) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.apache.el.parser.AstValue.invoke(AstValue.java:245) at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:277) at org.apache.myfaces.view.facelets.el.ContextAwareTagMethodExpression.invoke(ContextAwareTagMethodExpression.java:96) at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:88) at javax.faces.event.ActionEvent.processListener(ActionEvent.java:51) at javax.faces.component.UIC omponentBase.broadcast(UIComponentBase.java:409) at javax.faces.component.UICommand.broadcast(UICommand.java:103) at javax.faces.component.UIViewRoot._broadcastAll(UIViewRoot.java:1013) at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:284) at javax.faces.component.UIViewRoot._process(UIViewRoot.java:1302) at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:745) at org.apache.myfaces.lifecycle.InvokeApplicationExecutor.execute(InvokeApplicationExecutor.java:38) at org.apache.myfaces.lifecycle.LifecycleImpl.executePhase(LifecycleImpl.java:170) at org.apache.myfaces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:197) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1081) at org.apache.coyote.AbstractPro tocol$AbstractConnectionHandler.process(AbstractProtocol.java:658) at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:744) Caused by: java.lang.ClassNotFoundException: Foo (no security manager: RMI class loader disabled) at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:553) at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:646) at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:311) at sun.rmi.server.MarshalInputStream.resolv eProxyClass(MarshalInputStream.java:255) at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1558) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1514) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1771) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1350) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:370) ... 44 more

Also, I changed the port which Tomcat uses to do not have conflict with RMI port.

Answer 1

The client doesn't have the remote interface on its CLASSPATH, or, probably, the stub either. To avoid using a stub, add

super(0);

as the first line of the constructor.

NB you must store the result of createRegistry() in a static variable, to prevent the Registry from exiting.