How to update the large amount of thumbnail images in background process

[Theesh]

in my application i want to load large number of thumbnail images(each images set as icon for separate jradiobutton) into panel. This panel is in left side of JSplitPane.
when application is starting, now I’m loading the thumbnail buttons without image(to run the application quickly).
now i want to update the buttons with real thumbnail images in background. i tried with thread and SwingUtilities.invokeLater ,but it stuck the application until updating finish.
Note:im using java1.4 (not in the possession to use other versions)
Can anybody give suggestion?

Main GUI

	private void buildGUI(File selectedFile) {
		configButtonPanel();
		configThumbnailPanel(selectedFile);//loading with out thumbnail image
		new TestThread(selectedFile).run();
	}

Thread class

import javax.media.jai.NullOpImage;
import javax.media.jai.OpImage;
 
import com.sun.media.jai.codec.ImageCodec;
import com.sun.media.jai.codec.ImageDecoder;
import com.sun.media.jai.codec.TIFFDecodeParam;
 
public class TestThread extends Thread {
	File tiffImg;
 
	TestThread(File img) {
		this.tiffImg = img;
	}
 
	/*
	 * extracting form tiff images and creates thumbnail then add into vector
	 * 
	 */
	public void run() {
		ImageDecoder dec = null;
		Vector thumImagesV = new Vector();
		TIFFDecodeParam param = new TIFFDecodeParam();
		param.setDecodePaletteAsShorts(true);
		param.setJPEGDecompressYCbCrToRGB(true);
		try {
			dec = ImageCodec.createImageDecoder("tiff", tiffImg, param);
			int start, end = 0;
			for (int i = 0; i < dec.getNumPages(); i++) {
				RenderedImage rm = new NullOpImage(dec.decodeAsRenderedImage(i), null, OpImage.OP_IO_BOUND, null);
				thumImagesV.add(i, ImageHandler.createThumbnail(rm, 150));
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
 
}

[Fubarable]

1) In general you should avoid extending Thread but instead implement Runnable.
2) If you start a new Thread by calling run() it doesn't run as a background thread. Instead you must call start().

[PhHein]

Crosspost!
Swing - How to update the large amount of thumbnail images in background process

[Fubarable]

Crosspost!

Thanks for the warning. Theesh is on alert to change his behavior else no one will want to help him.