I have an issue binding a remote object to the RMI registry. I've reduced my code to a very simple example that works fine when I test it on my computer (Windows 10). But if I start it on another computer (Windows 7), when registry.bind(id, remoteObject); gets called, I get this exception:
java.lang.ClassNotFoundException:
rmitest.IRemote (no security manager: RMI class loader disabled)
I shouldn't need a SecurityManager since all class files are in the jar and I don't want to use the dynamic code loading feature.
Why does it try to load a security manager and why can't it find one even if I define one? What could be the reason that it works on one machine but not another? I think the code is ok and it must some configuration issue, but I'm not sure what exactly is configured wrong.
Here is the remote interface and remote object implementation, which I exported as runnable Jar in Eclipse as rmitest.jar.
public interface IRemote extends Remote {
void foo() throws RemoteException;
}
public class RemoteImpl extends UnicastRemoteObject implements IRemote {
private static Registry registry;
public RemoteImpl() throws RemoteException {
super();
}
public static void main(final String[] args) throws Exception {
try {
LocateRegistry.createRegistry(Registry.REGISTRY_PORT);
} catch (final Exception e) {
// already created
}
registry = LocateRegistry.getRegistry(Registry.REGISTRY_PORT);
registry.bind(UUID.randomUUID().toString(), new RemoteImpl());
System.out.println("Binding successful");
}
#Override
public void foo() throws RemoteException {
System.out.println("foo");
}
}
Here is the full stack trace, it throws in the line where registry.bind gets called and is exactly the same when running with either of the following commands:
java -jar rmitest.jar or
java -Djava.security.manager -Djava.security.policy=policy -jar rmitest.jar
It's quite strange that apparently in both cases a security manager is required but even in the second case it can't find one.
Exception in thread "main" java.rmi.ServerException: RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: rmitest.IRemote (no security manager: RMI class loader disabled)
at sun.rmi.server.UnicastServerRef.oldDispatch(Unknown Source)
at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
at sun.rmi.transport.Transport$1.run(Unknown Source)
at sun.rmi.transport.Transport$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
at sun.rmi.transport.StreamRemoteCall.exceptionReceivedFromServer(StreamRemoteCall.java:276)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:253)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:379)
at sun.rmi.registry.RegistryImpl_Stub.bind(Unknown Source)
at rmitest.RemoteImpl.main(RemoteImpl.java:29)
Caused by: java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: rmitest.IRemote (no security manager: RMI class loader disabled)
at sun.rmi.registry.RegistryImpl_Skel.dispatch(Unknown Source)
at sun.rmi.server.UnicastServerRef.oldDispatch(Unknown Source)
at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
at sun.rmi.transport.Transport$1.run(Unknown Source)
at sun.rmi.transport.Transport$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$256(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: rmitest.IRemote (no security manager: RMI class loader disabled)
at sun.rmi.server.LoaderHandler.loadProxyClass(Unknown Source)
at java.rmi.server.RMIClassLoader$2.loadProxyClass(Unknown Source)
at java.rmi.server.RMIClassLoader.loadProxyClass(Unknown Source)
at sun.rmi.server.MarshalInputStream.resolveProxyClass(Unknown Source)
at java.io.ObjectInputStream.readProxyDesc(Unknown Source)
at java.io.ObjectInputStream.readClassDesc(Unknown Source)
at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
... 15 more
Here is the policy file, which should allow everything:
grant {
permission java.security.AllPermission;
};
The problem was 'some other Java process' that was providing its own Registry, which didn't have access to your CLASSPATH. You would have found that if you had something better than an empty catch block for createRegistry().
The problem was some other Java process running which seemed to interfer with the registry binding. I don't know what this rogue process did exactly but killing it resolved the error. No security manager is needed and simply running the jar as usual works now.
Related
My previous question was deleted here because it was considered as duplicate. I say it's not because the answers were about java itself while mine is about charles proxy and those answers didn't resolve my problem.
I had installed jdk-17.0.1 and jre1.8.0_311 on my machine when I tried to open charles proxy 4.6.2 on double click but nothing happened, the application didn't start. I try to open via command prompt by typing Charles.exe and this error is shown
java.awt.AWTError: Assistive Technology not found: com.sun.java.accessibility.AccessBridge
at java.desktop/java.awt.Toolkit.newAWTError(Unknown Source)
at java.desktop/java.awt.Toolkit.fallbackToLoadClassForAT(Unknown Source)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(Unknown Source)
at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.copyInto(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source)
at java.base/java.util.stream.AbstractPipeline.evaluate(Unknown Source)
at java.base/java.util.stream.ReferencePipeline.forEach(Unknown Source)
at java.desktop/java.awt.Toolkit.loadAssistiveTechnologies(Unknown Source)
at java.desktop/java.awt.Toolkit.getDefaultToolkit(Unknown Source)
at de.sciss.syntaxpane.DefaultSyntaxKit.<clinit>(DefaultSyntaxKit.java:105)
at com.xk72.charles.gui.lib.UIUtils.<clinit>(Unknown Source)
at com.xk72.charles.gui.s.h(Unknown Source)
at com.xk72.charles.gui.Main.c(Unknown Source)
at com.xk72.charles.Main.b(Unknown Source)
at com.xk72.charles.gui.Main.main(Unknown Source)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at com.xk72.lib.a.a(Unknown Source)
at com.xk72.charles.gui.MainWithClassLoader.main(Unknown Source)
Caused by: java.lang.ClassNotFoundException: com.sun.java.accessibility.AccessBridge
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source)
at java.base/java.lang.ClassLoader.loadClass(Unknown Source)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Unknown Source)
... 24 more
I'm using Windows 10 64bit. %JAVA_HOME% is also setup
For me going to C:\Users\my account\.accessibility.properties and commenting out every line by adding a # a front of it worked.(I at least don't need the accessibility)
Found this solution at: Exception in thread "main" java.awt.AWTError: Assistive Technology not found
I'm deploying an application making use of EJB. I'have wrote an EJB and a java standalone client to connect to. Everything works correctly in Netbeans, but when i try to start in command line I got exceptions.
The JavaFX Application contains the following code :
String chemin = IRemoteInterface.class.getName();
Properties vEnv = new Properties();
vEnv.put("org.omg.CORBA.ORBInitialHost", "localhost");
vEnv.put("org.omg.CORBA.ORBInitialPort", "3700");
try {
Context ctx = new InitialContext(vEnv);
leProxy = (IRemoteInterface) ctx.lookup(chemin);
System.out.println("proxy OK");
} catch (NamingException ex) {
System.out.println("erreur proxy");
Logger.getLogger(CDM.class.getName()).log(Level.SEVERE, null, ex);
}
I have tried the following :
java -jar CDM.jar
And the error I get is :
javax.naming.NoInitialContextException: Cannot instantiate class: com.sun.enterprise.naming.impl.SerialInitContextFactory [Root exception is java.lang.NullPointerException]
at java.naming/javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
at java.naming/javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
at java.naming/javax.naming.InitialContext.init(Unknown Source)
at java.naming/javax.naming.InitialContext.<init>(Unknown Source)
at cdm.CDM.main(CDM.java:77)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.NullPointerException
at com.sun.enterprise.module.common_impl.AbstractModulesRegistryImpl.initializeServiceLocator(AbstractModulesRegistryImpl.java:152)
at com.sun.enterprise.module.common_impl.AbstractModulesRegistryImpl.newServiceLocator(AbstractModulesRegistryImpl.java:144)
at com.sun.enterprise.module.common_impl.AbstractModulesRegistryImpl.createServiceLocator(AbstractModulesRegistryImpl.java:218)
at com.sun.enterprise.module.common_impl.AbstractModulesRegistryImpl.createServiceLocator(AbstractModulesRegistryImpl.java:224)
at com.sun.enterprise.module.single.StaticModulesRegistry.createServiceLocator(StaticModulesRegistry.java:88)
at org.glassfish.internal.api.Globals.getStaticHabitat(Globals.java:102)
at com.sun.enterprise.naming.impl.SerialInitContextFactory.<init>(SerialInitContextFactory.java:130)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.base/java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.base/java.lang.Class.newInstance(Unknown Source)
... 16 more
I really don't know how to fix it.
Many thanks for your help in advance !
EDIT :
When I use the following it works
java -cp "C:\Program Files\glassfish5\glassfish\lib\appserv-rt.jar;C:\Program Files\glassfish5\glassfish\lib\javaee.jar;C:\Program Files\glassfish5\glassfish\lib\gf-client.jar;CDM.jar" cdm.CDM
I'm trying to connect my app to Facebook API, but I get following Exception when I execute the code:
Exception in thread "main" com.restfb.exception.FacebookNetworkException: A network error occurred while trying to communicate with Facebook: Facebook request failed (HTTP status code null)
at com.restfb.DefaultFacebookClient.makeRequestAndProcessResponse(DefaultFacebookClient.java:1024)
at com.restfb.DefaultFacebookClient.makeRequest(DefaultFacebookClient.java:952)
at com.restfb.DefaultFacebookClient.makeRequest(DefaultFacebookClient.java:914)
at com.restfb.DefaultFacebookClient.fetchObject(DefaultFacebookClient.java:392)
at Test.main(Test.java:18)
Caused by: java.net.SocketException: java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
at javax.net.ssl.DefaultSSLSocketFactory.throwException(Unknown Source)
at javax.net.ssl.DefaultSSLSocketFactory.createSocket(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.createSocket(Unknown Source)
at sun.net.NetworkClient.doConnect(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.http.HttpClient.openServer(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.<init>(Unknown Source)
at sun.net.www.protocol.https.HttpsClient.New(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection.plainConnect(Unknown Source)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.connect(Unknown Source)
at com.restfb.DefaultWebRequestor.execute(DefaultWebRequestor.java:374)
at com.restfb.DefaultWebRequestor.executeGet(DefaultWebRequestor.java:96)
at com.restfb.DefaultFacebookClient$3.makeRequest(DefaultFacebookClient.java:965)
at com.restfb.DefaultFacebookClient.makeRequestAndProcessResponse(DefaultFacebookClient.java:1022)
... 4 more
Caused by: java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: sun.security.ssl.SSLContextImpl$DefaultSSLContext)
at java.security.Provider$Service.newInstance(Unknown Source)
at sun.security.jca.GetInstance.getInstance(Unknown Source)
at sun.security.jca.GetInstance.getInstance(Unknown Source)
at javax.net.ssl.SSLContext.getInstance(Unknown Source)
at javax.net.ssl.SSLContext.getDefault(Unknown Source)
at javax.net.ssl.SSLSocketFactory.getDefault(Unknown Source)
at javax.net.ssl.HttpsURLConnection.getDefaultSSLSocketFactory(Unknown Source)
at javax.net.ssl.HttpsURLConnection.<init>(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.<init>(Unknown Source)
at sun.net.www.protocol.https.Handler.openConnection(Unknown Source)
at sun.net.www.protocol.https.Handler.openConnection(Unknown Source)
at java.net.URL.openConnection(Unknown Source)
at com.restfb.DefaultWebRequestor.openConnection(DefaultWebRequestor.java:219)
at com.restfb.DefaultWebRequestor.execute(DefaultWebRequestor.java:365)
... 7 more
Caused by: java.io.IOException: Invalid keystore format
at sun.security.provider.JavaKeyStore.engineLoad(Unknown Source)
at sun.security.provider.JavaKeyStore$JKS.engineLoad(Unknown Source)
at sun.security.provider.KeyStoreDelegator.engineLoad(Unknown Source)
at sun.security.provider.JavaKeyStore$DualFormatJKS.engineLoad(Unknown Source)
at java.security.KeyStore.load(Unknown Source)
at sun.security.ssl.TrustManagerFactoryImpl.getCacertsKeyStore(Unknown Source)
at sun.security.ssl.SSLContextImpl$DefaultSSLContext.getDefaultTrustManager(Unknown Source)
at sun.security.ssl.SSLContextImpl$DefaultSSLContext.<init>(Unknown Source)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
... 21 more
I think it's important to mention that I was getting the same exception when trying to run code with facebook4j.
I spent a lot of time trying to figure out, and I'm really stuck.
Code for the test class:
import com.restfb.DefaultFacebookClient;
import com.restfb.FacebookClient;
import com.restfb.Version;
import com.restfb.types.User;
public class Test {
public Test() {
}
public static void main(String[] args) {
String accessToken = "******";
FacebookClient fc = new DefaultFacebookClient(accessToken, Version.UNVERSIONED); // Setting version has no effect
User me = fc.fetchObject("me", User.class);
System.out.println(me.getFirstName());
System.out.println(me.getLanguages());
}
}
Ok, I tried to run the code on different machine, and it comes out that there was an issue with setup of development enviroment.
I have a java applet which uses a proxy service to a WCF Service to display data. The applet compiles and runs perfectly in Eclipse but when I build and export a Jar file then run it in a html page it fails with
java.lang.NoClassDefFoundError: javax/xml/rpc/ServiceException.
I have included jaxrpc.jar in my build path and my jar file contains all necessary classes.
The stack trace seems to be complaining about the line where I instantiate the proxy service from within the applet class. Does anyone know if there is an issue calling WCF service from a java applet?
Stack Trace:
java.lang.RuntimeException: java.lang.NoClassDefFoundError: javax/xml/rpc/ServiceException
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter.instantiateApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.initAppletAdapter(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NoClassDefFoundError: javax/xml/rpc/ServiceException
at ListProducts.ListProducts.<init>(ListProducts.java:25)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at com.sun.deploy.uitoolkit.impl.awt.AWTAppletAdapter$1.run(Unknown Source)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$200(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: javax.xml.rpc.ServiceException
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 27 more
This has been troubling me all day.
I think your issue is loading rpc jar, not call to wcf.
This post can be helpfull:
http://www.coderanch.com/t/259357/Applets/java/Applet-Axis-Client-Errors
It recomemds to sign your jar, verify you can access all your jars via browser, ensure you have all dependent.jars.
If all this will not help - i'd try to solve it as "
NoClassDefFoundError from spplet" issue.
Ok. I got this working by doing several things:
First I had to sign several of the jar files I was using:
jaxrpc.jar
axis.jar
commons-discovery-0.2.jar
but not:
javax.wsdl_1.6.2.v201012040545.jar
org.apache.commons.logging_1.0.4.v201101211617.jar
Secondly - all these files had to exist in the same directory as the html page, as I didn't specify a directory in codebase property for the applet tag.
Thirdly, within my main applet (ListProducts.class) I had to use AccessController.doPrivileged() around the code that first calls the proxy service:
EDIT: This step may not be necessary, as it now seems to work when I remove the doPrivileged block.
AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
try {
//instantiate proxy service and make rpc's
//do other stuff with results...
} catch (RemoteException e) {
// catch error
}
return null;
}
});
This combination of things got the java applet doing what it should. It was a painful slow process to discover which jar files were missing and then signing the appropriate ones.
I'm having some problems while trying to open a web-client for a game that I play. I get this error and I don't know what to do. Help would be appreciated. If you need any more information please let me know and I will do the best I can to get it.
load: class client.class not found.
java.lang.ClassNotFoundException: client.class
at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Exception: java.lang.ClassNotFoundException: client.class
It seems you are running your web client like this:
$ java client.class
Try running this instead:
$ java client