JAR File Will NOT Update on WebStart!

Question

I want an updated jar application to run on WebStart, but it always runs the original jar file I put on the server. (The update of the jar file works fine by itself.) I have updated the .jar file as well as the .jnlp file. I have tried deleting the cache in Webstart. I have also fully reloaded WebStart, and the .jar files when nothing else worked. I even totally renamed the .jar and .jnlp files, and it still runs the original file. Everything else works smoothly.
Any suggestions?

Answer 1

If you want your application to always check for a new version, you should use the JNLP API, i think the DownloadService(http://java.sun.com/products/javawebstart/docs/javadoc/javax/jnlp/DownloadService.html) interface will do the job. Here�s an example:
import javax.jnlp.*;
    DownloadService ds;
    try {
        ds = (DownloadService)ServiceManager.lookup("javax.jnlp.DownloadService");
    } catch (UnavailableServiceException e) {
        ds = null;
    if (ds != null) {
        try {
            URL url =
                    new URL("http://java.sun.com/products/javawebstart/lib/YOURAPP.jar");
            if ( ! YourApp.isLastVersion() ) { // some method to check versions on the server....
                ds.removeResource(url, "1.0");
                // reload the resource into the cache
               DownloadServiceListener dsl = ds.getDefaultProgressWindow();
               ds.loadResource(url, "1.0", dsl);
        } catch (Exception e) {
            e.printStackTrace();
    }