CODEWITHSUNDEEP
javarmi
SEngineerJay
SEngineerJay

Reputation: 7

Sending over Interface Object from method call hiding implementation super class on server via RMI?

Say I have class SuperNode and an interface Node:

SuperNode implements Node

I have a RMI-Implementation server side and I'm trying to just send the Node over from a method without the user having the source file for SuperNode but they do have the interface Node. 

public Node RMIImplServer.getNode();

When I do this I get this error:

java.rmi.UnmarshalException: error unmarshalling return; nested exception is: java.lang.ClassNotFoundException: SEHT.somepackage.SuperNode (no security manager: RMI class loader disabled) at sun.rmi.server.UnicastRef.invoke(Unknown Source) at java.rmi.server.RemoteObjectInvocationHandler.invokeRemoteMethod(Unknown Source) at java.rmi.server.RemoteObjectInvocationHandler.invoke(Unknown Source) at com.sun.proxy.$Proxy0.getDataNodes(Unknown Source) Caused by: java.lang.ClassNotFoundException: SEHT.somepackage.SuperNode (no security manager: RMI class loader disabled) at sun.rmi.server.LoaderHandler.loadClass(Unknown Source) at sun.rmi.server.LoaderHandler.loadClass(Unknown Source) at java.rmi.server.RMIClassLoader$2.loadClass(Unknown Source) at java.rmi.server.RMIClassLoader.loadClass(Unknown Source) at sun.rmi.server.MarshalInputStream.resolveClass(Unknown Source) at java.io.ObjectInputStream.readNonProxyDesc(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) at java.util.ArrayList.readObject(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at java.io.ObjectStreamClass.invokeReadObject(Unknown Source) at java.io.ObjectInputStream.readSerialData(Unknown Source) at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) at java.io.ObjectInputStream.readObject0(Unknown Source) at java.io.ObjectInputStream.readObject(Unknown Source) at sun.rmi.server.UnicastRef.unmarshalValue(Unknown Source) ... 5 more

Is what I'm trying to do possible, if so what am I doing wrong, any help would be appreciated.

Finally figured it out...the jar file wasn't including the right files due to a stupid default that I didn't check. Thank you so much EJP for your help.

Upvotes: 0

Views: 527

Answers (1)

user207421
user207421

Reputation: 311039

The client doesn't need any source files. It does however need the object files (.class) files for all types returned by remote methods, available on its CLASSPATH, unless:

... if you don't want to deploy SuperNode.class or whatever it is at the client, you can use the codebase feature. It's complicated.

  1. You will need to install a security manager at the client.
  2. You will need to define the system property java.rmi.server.codebase at the server JVM.
  3. You will need to set it to one or more URLs that are intelligible to the client and that name JAR file(s) containing classes to be loaded dynamically. Typically a codebase item is an HTTP URL. Note that a codebase item referring to the file system local to the server cannot work, as it isn't intelligible to the client.

Upvotes: 0

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