RMI memory leak

Question

My program use RMI, and I remark memory leak, then I tried RMI sample from jbuilder6, I modified this sample, to send 1Mb file via RMI.
I write how much RAM are used
before 168 mb
rmiregistry 172Mb used 8 Mb
RMIserver 189Mb 18 Mb
RMIclient up to 227Mb 38Mb
end when RMIclient exit 212Mb where is 23 Mb??? 212-189 ????
This is my changes, and all program are after that:
public String getDate() {
System.out.println("SimpleRMIImpl.getDate()");
String s=null;
try {
InputStream fileIn = new FileInputStream("Readme.txt2");
byte buff[] = new byte[fileIn.available()];
int i = fileIn.read(buff);
s = new String(buff);
} catch(FileNotFoundException e) {
e.printStackTrace();
} catch(IOException e) {
e.printStackTrace();
return new String(s);
All program:
package com.borland.samples.rmi;
import java.rmi.*;
import java.rmi.registry.*;
import java.rmi.server.*;
import java.util.Date;
public class SimpleRMIClient
public static void main(String[] argv) {
String serverName = "";
System.setSecurityManager(new RMISecurityManager());
if (argv.length != 1) {
try {
serverName = java.net.InetAddress.getLocalHost().getHostName();
catch(Exception e) {
e.printStackTrace();
else {
serverName = argv[0];
if (serverName == "") {
System.out.println("usage: java SimpleRMIClient <IP address of host running RMI server>");
System.exit(0);
try {
//bind server object to object in client
SimpleRMIInterface myServerObject = (SimpleRMIInterface) Naming.lookup("//"+serverName+"/SimpleRMIImpl instance");
//invoke method on server object
String d = myServerObject.getDate();
System.out.println("Date on server is " + d);
catch(Exception e) {
System.out.println("Exception occured: " + e);
System.exit(0);
System.out.println("RMI connection successful");
package com.borland.samples.rmi;
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.FileInputStream;
public class SimpleRMIImpl extends UnicastRemoteObject implements SimpleRMIInterface
public SimpleRMIImpl(String name) throws RemoteException {
super();
try {
Naming.rebind(name, this);
catch (Exception e) {
if (e instanceof RemoteException)
throw (RemoteException)e;
else
throw new RemoteException(e.getMessage());
public String getDate() {
System.out.println("SimpleRMIImpl.getDate()");
String s=null;
try {
InputStream fileIn = new FileInputStream("Readme.txt2");
byte buff[] = new byte[fileIn.available()];
int i = fileIn.read(buff);
s = new String(buff);
} catch(FileNotFoundException e) {
e.printStackTrace();
} catch(IOException e) {
e.printStackTrace();
return new String(s);
package com.borland.samples.rmi;
public interface SimpleRMIInterface extends java.rmi.Remote
public String getDate() throws java.rmi.RemoteException;
package com.borland.samples.rmi;
import java.rmi.*;
import java.rmi.server.UnicastRemoteObject;
public class SimpleRMIServer
public static void main(String[] argv) {
System.setSecurityManager(new RMISecurityManager());
try {
SimpleRMIImpl implementation = new SimpleRMIImpl("SimpleRMIImpl instance");
System.out.println("SimpleRMIImpl ready");
catch (Exception e) {
System.out.println("Exception occurred: " + e);
Can you explain why this program use so much memory?
Valdas

Answer 1

Memory Usage and its distribution are done by the JVM....u cannot posibly account for each Mega bit of memory while it is used. Also, the File Copying Operation Involves JVM interacting with the OS which in turn interacts with the peripeherals such as ur harddisk, which are comparetively slower then the Processor speed. So the bottom line is ur same program will work at different RAM levels in diff machines with diff hardwares......If u system is indeed working too much then u can check out and sut down many services that u might have otherwise started...posiiblity of a Virus should not be ruled out either.....and the code itself is no problem at all although u might increase a bit by using some FIleReader, BufferredReader/Writer and other faster Streams.
Hope it helps,
Cheers,
Manja