standalone EJB client, failed

[edward]

Hi, ALL,

I am trying to write a standalone EJB client, but failed.
I have a standalone OpenEJB in C drive, I place simple-stateless-1.0.jar 
into its app folder. This jar is from OpenEjb example. It works, from 
log I can see,

///////////////
2011-05-09 21:07:30,825 - INFO  - Jndi(name=CalculatorImplLocal) --> 
Ejb(deployment-id=CalculatorImpl)
2011-05-09 21:07:30,827 - INFO  - Jndi(name=CalculatorImplRemote) --> 
Ejb(deployment-id=CalculatorImpl)
2011-05-09 21:07:30,856 - INFO  - Created 
Ejb(deployment-id=CalculatorImpl, ejb-name=CalculatorImpl, container=My 
Stateless Container)
2011-05-09 21:07:30,856 - INFO  - Deployed 
Application(path=C:\openejb-3.1.4\apps\simple-stateless-1.0.jar)
///////////////

Now the clinent is
//////////////////////
Properties properties = new Properties();
        properties.setProperty(Context.INITIAL_CONTEXT_FACTORY, 
"org.apache.openejb.client.RemoteInitialContextFactory");
        //properties.put("java.naming.provider.url", 
"ejbd://localhost:4201");
        properties.put("java.naming.provider.url", 
"http://localhost:4204/ejb";);

        InitialContext initialContext = new InitialContext(properties);

        Object object = initialContext.lookup("CalculatorImplRemote");
/////////////////////////////
It always give me error:

/////////////////
Exception in thread "main" javax.naming.NamingException: Cannot lookup 
'/CalculatorImplRemote'. [Root exception is java.rmi.RemoteException: 
Cannot open object input stream to server (OEJP/3.1) : null; nested 
exception is:
    java.io.EOFException]
    at org.apache.openejb.client.JNDIContext.lookup(JNDIContext.java:240)
    at javax.naming.InitialContext.lookup(Unknown Source)
    at com.Test.main(Test.java:20)
Caused by: java.rmi.RemoteException: Cannot open object input stream to 
server (OEJP/3.1) : null; nested exception is:
    java.io.EOFException
    at org.apache.openejb.client.Client.processRequest(Client.java:159)
    at org.apache.openejb.client.Client.request(Client.java:42)
    at org.apache.openejb.client.JNDIContext.request(JNDIContext.java:87)
    at org.apache.openejb.client.JNDIContext.lookup(JNDIContext.java:234)
    ... 2 more
Caused by: java.io.EOFException
    at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source)
    at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown 
Source)
    at java.io.ObjectInputStream.readStreamHeader(Unknown Source)
    at java.io.ObjectInputStream.<init>(Unknown Source)
    at 
org.apache.openejb.client.EjbObjectInputStream.<init>(EjbObjectInputStream.java:31)
    at org.apache.openejb.client.Client.processRequest(Client.java:156)
    ... 5 more

////////
I am using  openejb-itests-standalone-client-3.0.jar as its reference api.

Please help me on this.

Thanks
Edward