java.lang.ClassCastException

[shwetagarg]

I have deployed a bean and I m using a servlet client to access the bean.I m using the following code :

LoginHome loginHome;
Hashtable env = new Hashtable();
env.put(Context.INITIAL_CONTEXT_FACTORY,"org.jnp.interfaces.NamingContextFactory");
String url = "localhost:1099";
env.put(Context.PROVIDER_URL, url);
Context ctx = new InitialContext(env);

Object objref = ctx.lookup("ejb/quiz/LoginBean");
loginHome = (LoginHome)PortableRemoteObject.narrow(objref, LoginHome.class);


I have put <jndi-name>ejb/quiz/LoginBean</jndi-name> tag in jboss.xml and then build the ear file.
But, when I try to get access to bean using my servlet client I get the following exception raised at JBoss server :

12:52:04,900 ERROR [STDERR] java.lang.ClassCastException
12:52:04,900 ERROR [STDERR] at com.sun.corba.se.internal.javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:293)
12:52:04,900 ERROR [STDERR] at javax.rmi.PortableRemoteObject.narrow(PortableRemoteObject.java:134)
12:52:04,900 ERROR [STDERR] at quiz.login.CheckUserServlet.doGet(CheckUserServlet.java:80)
12:52:04,900 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
12:52:04,900 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
12:52:04,900 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
12:52:04,900 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
12:52:04,900 ERROR [STDERR] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:260)
12:52:04,900 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:04,900 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invokeContainerBase.java:995)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2396)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:04,910 ERROR [STDERR] at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
12:52:05,021 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:469)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1040)
12:52:05,031 ERROR [STDERR] at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1151)
12:52:05,101 ERROR [STDERR] at java.lang.Thread.run(Thread.java:536)
12:52:05,101 ERROR [STDERR] java.lang.NullPointerException
12:52:05,101 ERROR [STDERR] at quiz.login.CheckUserServlet.doGet(CheckUserServlet.java:116)
12:52:05,111 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
12:52:05,111 ERROR [STDERR] at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:247)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:193)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:260)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.valves.CertificatesValve.invoke(CertificatesValve.java:246)
12:52:05,111 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2396)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:180)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.java:170)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:172)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:469)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:641)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,121 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,261 ERROR [STDERR] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:174)
12:52:05,261 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline$StandardPipelineValveContext.invokeNext(StandardPipeline.java:643)
12:52:05,271 ERROR [STDERR] at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:480)
12:52:05,271 ERROR [STDERR] at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:995)
12:52:05,271 ERROR [STDERR] at org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:1040)
12:52:05,271 ERROR [STDERR] at org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1151)
12:52:05,271 ERROR [STDERR] at java.lang.Thread.run(Thread.java:536)

Please help me

Thanx and regards
Shweta

[dkny74]

Hi, i'm having the same problem. Some people have suggested to not use the PortableRemoteObject.narrow(), but i still get the same error.

Have u found out how to correct this error ?
I deployed a jar file for my bean and a war file for my webapplication. Do i need to put my bean and servlet file in a ear application to make it work ?

any insight will be gratefull,

in great despair!!!

[charvolant]

I'm also having the same problem.

I can see the deployed bean in the JNDI tree as:

+- ejb (class: org.jnp.interfaces.NamingContext)
| +- member (class: org.jnp.interfaces.NamingContext)
| | +- UIDStream (proxy: $Proxy30 implements interface org.charvolant.callout.base.UIDStreamRemoteHome,interface javax.ejb.Handle)

Using code of the form:

public void setUp() throws Exception {
Properties props;
InitialContext ctx;
Object h;

props = new Properties();
props.load(this.getClass().getResourceAsStream("jndi.properties"));
ctx = new InitialContext(props);
h = ctx.lookup(this.UIDSTREAMTEST);
System.err.println("Expected class is " + UIDStreamRemoteHome.class);
System.err.println("Stream home is " + h + " class " + h.getClass());
this.home = (UIDStreamRemoteHome) PortableRemoteObject.narrow(h, UIDStreamRemoteHome.class); }

Nets me the output:

Expected class is interface org.charvolant.callout.base.UIDStreamRemoteHome
Stream home is ejb/member/UIDStreamHome class class $Proxy0

[charvolant]

To continue,

I've tried the same code with JDK 1.3.1 and JDK 1.4.1 with the same results.

What's wierd is that if I include a little extra code:

public void setUp() throws Exception {
Properties props;
InitialContext ctx;
Object h;
Class[] classes;
int i;

props = new Properties();
props.load(this.getClass().getResourceAsStream("jndi.properties"));
ctx = new InitialContext(props);
h = ctx.lookup(this.UIDSTREAMTEST);
System.err.println("Expected class is " + UIDStreamRemoteHome.class);
System.err.println("Stream home is " + h + " class " + h.getClass());
classes = h.getClass().getInterfaces();
System.err.println("Number of interfaces: " + classes.length);
for (i = 0; i < classes.length; i++) {
System.err.println("Interface=" + classes[ i ]);
}
this.home = (UIDStreamRemoteHome) PortableRemoteObject.narrow(h, UIDStreamRemoteHome.class);
}

I get the following output

Expected class is interface org.charvolant.callout.base.UIDStreamRemoteHome
Stream home is ejb/member/UIDStreamHome class class $Proxy0
Number of interfaces: 2
Interface=interface org.charvolant.callout.base.UIDStreamRemoteHome
Interface=interface javax.ejb.Handle

So $Proxy0 does claim to implement the interface, even if the cast throws an exception.

What's even more interesting is that if I set my classpath to point to the deployed member.jar, instead of the directory tree with class files in it, I get the following exception:

javax.naming.CommunicationException. Root exception is java.lang.ClassNotFoundException: org.charvolant.callout.base.UIDStreamRemoteHome (no security manager: RMI class loader disabled)
at sun.rmi.server.LoaderHandler.loadProxyClass(LoaderHandler.java:521)
at java.rmi.server.RMIClassLoader$2.loadProxyClass(RMIClassLoader.java:639)
at java.rmi.server.RMIClassLoader.loadProxyClass(RMIClassLoader.java:309)
at sun.rmi.server.MarshalInputStream.resolveProxyClass(MarshalInputStream.java:241)
at java.io.ObjectInputStream.readProxyDesc(ObjectInputStream.java:1469)
at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1432)
at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1626)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1274)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:324)
at java.rmi.MarshalledObject.get(MarshalledObject.java:135)
at org.jnp.interfaces.MarshalledValuePair.get(MarshalledValuePair.java:30)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:483)
at org.jnp.interfaces.NamingContext.lookup(NamingContext.java:443)
at javax.naming.InitialContext.lookup(InitialContext.java:347)
at org.charvolant.callout.base.test.UIDStreamTest.setUp(UIDStreamTest.java:52)

So it would appear that the junit specialised ClassLoader does something icky.

Using the text UI or the swing UI with the -noloading flag (and making sure that everything has cleanly rebuilt and deployed) and not using interfaces packaged into client jars, but just having a directory tree with .class files in it, gets things going.