Hello, I rarely post here, but I’m a bit stumped with this one 
JTable with a surrounding JScrollPane (when used in JMEDesktop) seems to go through some serious memory problems when you try to scroll it.
I’ve created a Test file consisting of a simple JTable of just 44 rows and 5 columns, with simple text data. I also added a button that will remove the table and force a garbage collection to happen.
Loading it up is fine, the memory is acceptable at this point and is comparable to running the table in a normal Swing application. However if you scroll up and down you’ll notice a huge leap in memory usage (a normal swing app wouldn’t do this).
Here’s an image of the memory usage:
At position (1) I’ve loaded the application but not clicked on anything yet. Usage here is 59 MB
At position (2) I’ve scrolled the table to the very bottom.
At position (3) I’ve scrolled it back up to the top. Notice that a bit of automatic garbage collection happened as I was scrolling upwards.
After here I rapidly move the scrollbar up and down for a while which resulted in the spikeyness between (3) and (4). This peaks at a usage of a whopping 340 MB
I then pressed the button removing the table and forcing a garbage collection which then puts me at position (4) 66 MB.
So I don’t think there’s a memory leak since position (4) has almost the same usage as position (1), however there’s clearly an issue of it using far more memory than needed to scroll such a simple table.
Running the same test in a normal swing app results in an almost constant memory usage throughout.
Here’s the test case that I used to get the results above (code borrowed in part from TestJMEDesktop.java):
TestJTable.java:
[java]
/*
- Copyright © 2003-2009 jMonkeyEngine
- All rights reserved.
*
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- met:
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- notice, this list of conditions and the following disclaimer.
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- documentation and/or other materials provided with the distribution.
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- may be used to endorse or promote products derived from this software
- without specific prior written permission.
*
- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
- CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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package jmetest.awt.swingui;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.lang.reflect.InvocationTargetException;
import java.net.URL;
import javax.swing.JDesktopPane;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
import com.jme.app.SimpleGame;
import com.jme.image.Image;
import com.jme.image.Texture;
import com.jme.input.AbsoluteMouse;
import com.jme.input.InputHandler;
import com.jme.input.KeyboardLookHandler;
import com.jme.renderer.ColorRGBA;
import com.jme.renderer.Renderer;
import com.jme.scene.Node;
import com.jme.scene.Spatial;
import com.jme.scene.state.BlendState;
import com.jme.scene.state.TextureState;
import com.jme.system.DisplaySystem;
import com.jme.util.TextureManager;
import com.jmex.awt.swingui.JMEDesktop;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
/
*
*/
public class TestJMEJTable extends SimpleGame
{
private JMEDesktop jmeDesktop;
private Node desktopNode;
private KeyboardLookHandler lookHandler;
public TestJMEJTable()
{
}
protected void simpleUpdate()
{
if ( jmeDesktop.getFocusOwner() == null )
{
lookHandler.setEnabled( true );
}
else
{
lookHandler.setEnabled( false );
}
}
public static void main( String[] args ) throws Exception
{
TestJMEJTable testJMEJTable = new TestJMEJTable();
testJMEJTable.setConfigShowMode( ConfigShowMode.AlwaysShow );
testJMEJTable.start();
}
/
- Called near end of initGame(). Must be defined by derived classes.
*/
protected void simpleInitGame()
{
display.setTitle( “jME-JTable test” );
display.getRenderer().setBackgroundColor( ColorRGBA.red.clone() );
// move the ‘default’ keys (debug normals, toggle lighting, etc.) to a separated input handler
InputHandler handlerForDefaultKeyActions = input;
// remove the first person nested handlers
handlerForDefaultKeyActions.removeAllFromAttachedHandlers();
// create a new handler for our input
input = new InputHandler();
// add the default handler as a child
input.addToAttachedHandlers( handlerForDefaultKeyActions );
// create another look handler
lookHandler = new KeyboardLookHandler( cam, 50, 1 );
// and nest it
input.addToAttachedHandlers( lookHandler );
jmeDesktop = new JMEDesktop( “test internalFrame” );
jmeDesktop.setup( display.getWidth(), display.getHeight(), false, input );
jmeDesktop.setLightCombineMode( Spatial.LightCombineMode.Off );
desktopNode = new Node( “desktop node” );
desktopNode.attachChild( jmeDesktop );
rootNode.attachChild( desktopNode );
rootNode.setCullHint( Spatial.CullHint.Never );
fullScreen();
jmeDesktop.getJDesktop().setBackground( new Color( 1, 1, 1, 0.2f ) );
try
{
SwingUtilities.invokeAndWait( new Runnable()
{
public void run()
{
// Only access the Swing UI from the Swing event dispatch thread!
// See SwingUtilities.invokeLater()
// and http://java.sun.com/docs/books/tutorial/uiswing/concurrency/index.html for details.
createSwingStuff();
}
} );
}
catch ( InterruptedException e )
{
// ok - just leave
return;
}
catch ( InvocationTargetException e )
{
throw new RuntimeException( e );
}
createCustomCursor();
}
private void createCustomCursor()
{
cursor = new AbsoluteMouse( “cursor”, display.getWidth(), display.getHeight() );
// Get a picture for my mouse.
TextureState ts = display.getRenderer().createTextureState();
URL cursorLoc = TestJMEJTable.class.getClassLoader().getResource(
“jmetest/data/cursor/cursor1.png” );
Texture t = TextureManager.loadTexture( cursorLoc, Texture.MinificationFilter.NearestNeighborNoMipMaps,
Texture.MagnificationFilter.Bilinear, Image.Format.GuessNoCompression, 1, true );
ts.setTexture( t );
cursor.setRenderState( ts );
// Make the mouse’s background blend with what’s already there
BlendState as = display.getRenderer().createBlendState();
as.setBlendEnabled( true );
as.setSourceFunction( BlendState.SourceFunction.SourceAlpha );
as.setDestinationFunction( BlendState.DestinationFunction.OneMinusSourceAlpha );
as.setTestEnabled( true );
as.setTestFunction( BlendState.TestFunction.GreaterThan );
cursor.setRenderState( as );
// Assign the mouse to an input handler
cursor.registerWithInputHandler( input );
statNode.attachChild( cursor );
// important for JMEDesktop: use system coordinates
cursor.setUsingDelta( false );
cursor.getXUpdateAction().setSpeed( 1 );
cursor.getYUpdateAction().setSpeed( 1 );
cursor.setCullHint( Spatial.CullHint.Never );
}
private void fullScreen()
{
final DisplaySystem display = DisplaySystem.getDisplaySystem();
desktopNode.getLocalRotation().set( 0, 0, 0, 1 );
desktopNode.getLocalTranslation().set( display.getWidth() / 2, display.getHeight() / 2, 0 );
desktopNode.getLocalScale().set( 1, 1, 1 );
desktopNode.setRenderQueueMode( Renderer.QUEUE_ORTHO );
desktopNode.setCullHint( Spatial.CullHint.Never );
}
private AbsoluteMouse cursor;
private JScrollPane pane = null;
protected void createSwingStuff()
{
final JDesktopPane desktopPane = jmeDesktop.getJDesktop();
desktopPane.removeAll();
JTable table = createJTable();
pane = new JScrollPane();
pane.setViewportView(table);
pane.setLocation(50, 50);
pane.setSize(300, 300);
desktopPane.add(pane);
JButton button = new JButton(“Remove Table and Garbage Collect”);
button.setSize(button.getPreferredSize());
button.setLocation(400, 50);
desktopPane.add(button);
button.addActionListener(new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
if (pane != null)
{
desktopPane.remove(pane);
pane = null;
}
desktopPane.repaint();
desktopPane.revalidate();
Runtime.getRuntime().gc();
}
});
desktopPane.repaint();
desktopPane.revalidate();
}
private JTable createJTable()
{
DefaultTableModel model = new DefaultTableModel();
JTable table = new JTable(model);
model.addColumn(“Name”);
model.addColumn(“Title”);
model.addColumn(“Note”);
model.addColumn(“Creation”);
model.addColumn(“Enabled”);
for (int i=0; i<44; i++)
{
model.addRow(new Object[] { “Bob”, “Mister”, “Low”, String.valueOf(i), “-”});
}
table.setOpaque(false);
return table;
}
protected void cleanup()
{
if ( jmeDesktop != null )
{
jmeDesktop.dispose();
}
super.cleanup();
}
}
[/java]
To see the same table in a simple swing application:
[java]
package jmetest.awt.swingui;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class JTableApp
{
public static void main(String[] args)
{
javax.swing.SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
//Create and set up the window.
JFrame frame = new JFrame(“JTableApp”);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTable table = createJTable();
JScrollPane pane = new JScrollPane();
pane.setViewportView(table);
pane.setLocation(50, 50);
pane.setSize(300, 300);
frame.getContentPane().add(pane);
//Display the window.
frame.pack();
frame.setVisible(true);
}
private static JTable createJTable()
{
DefaultTableModel model = new DefaultTableModel();
JTable table = new JTable(model);
model.addColumn(“Name”);
model.addColumn(“Title”);
model.addColumn(“Note”);
model.addColumn(“Creation”);
model.addColumn(“Enabled”);
for (int i=0; i<44; i++)
{
model.addRow(new Object[] { “Bob”, “Mister”, “Low”, String.valueOf(i), “-”});
}
table.setOpaque(false);
return table;
}
}
[/java]