How to get Remote Data from a file which is in remote system

Question

Hi everybody,
I have developed four classes.
FileInterface.java:-
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface FileInterface extends Remote {
public byte[] downloadFile(String fileName) throws
RemoteException;
FileServer.java:-
import java.io.*;
import java.rmi.*;
public class FileServer {
public static void main(String argv[]) {
if(System.getSecurityManager() == null) {
System.setSecurityManager(new RMISecurityManager());
try {
FileInterface fi = new FileImpl("FileServer");
Naming.rebind("//10.161.15.219/FileServer", fi);
} catch(Exception e) {
System.out.println("FileServer: "+e.getMessage());
e.printStackTrace();
FileImpl.java:-
import java.io.*;
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject;
public class FileImpl extends UnicastRemoteObject
implements FileInterface {
private String name;
public FileImpl(String s) throws RemoteException{
super();
name = s;
public byte[] downloadFile(String fileName){
try {
File file = new File(fileName);
byte buffer[] = new byte[(int)file.length()];
BufferedInputStream input = new
BufferedInputStream(new FileInputStream(fileName));
input.read(buffer,0,buffer.length);
input.close();
return(buffer);
} catch(Exception e){
System.out.println("FileImpl: "+e.getMessage());
e.printStackTrace();
return(null);
FileClient.java:-
import java.io.*;
import java.rmi.*;
public class FileClient{
public static void main(String argv[]) {
try {
String name = "//10.161.15.219/FileServer";
System.out.println("1");
FileInterface fi = (FileInterface) Naming.lookup(name);
System.out.println("2");
byte[] filedata = fi.downloadFile("//10.161.15.88/C/RMITEST/Test.txt");
System.out.println("3");
File file = new File("//10.161.15.219/T.txt");
System.out.println("4");
BufferedOutputStream output = new
BufferedOutputStream(new FileOutputStream(file.getName()));
output.write(filedata,0,filedata.length);
output.flush();
output.close();
} catch(Exception e) {
System.err.println("FileServer exception: "+ e.getMessage());
e.printStackTrace();
Now Iam trying to access text file which is in remote s/m.
It is developing stub and skeleton classes,when i run it is coming for local
If I want to access remotely the error is coming like this
1
2
3
FileServer exception: null4
java.lang.NullPointerException
     at FileClient.main(FileClient.java:18)
Can anybody help me please.

Answer 1

Probably the easiest way in this case is to run the performance trace (System/Utilities/Performance trace). Start transaction MD04, put on the trace in another window, press enter to see the stock/requirements list, then stop the trace and list the results. Then you'll see which tables were accesses with which queries.