Returning Rowset From Remote Server Error

Question

I'm currently trying to pass a rowset back to my client application via RMI. I keep getting a "java.rmi.UnmarshalException: error unmarshalling return; nested exception is: java.io.EOFException" message. It works fine if I pass a String object. I can pass a rowset if I use localhost rather than my remote server. Any help would be greatly appreciated. Thank you.

Answer 1

I had this very same problem. The problem is that ResultSet (from java.sql.*) is not Serializable, and cannot be marshalled via RMI (i.e. sent back down the pipe). String, int and Boolean all work. RowSet is abstract and cannot be initialised. The best subclass of RowSet I've found is CachedRowSetImpl, which inherits all the standard RowSet attributes and methods.
You will need to download the JAR containing "com.sun.rowset" from here:
http://java.sun.com/developer/earlyAccess/jdbc/jdbc-rowset.html
... then take the "rowset.jar" file and place it somewhere your IDE can find it (I placed mine here: C:\Program Files\Java\jdk1.5.0_01\jre\lib\ext). Under NetBeans, you can enter the Platform Manager (Tools) and force NetBeans to see it. Then the command:
import com.sun.rowset.*;
...will allow you to create CachedRowSetImpl objects with the simple constructor:
CachedRowSetImpl myCRS = new CachedRowSetImpl( );
You can populate a CRS with the command:
myCRS.populate(existingResultSet);
Hope this was helpful.
JGI