Enabling JavaHelp to open Acrobat for PDF links

Question

I currently have a working help set which has one or two href links to pdf files.
When clicked, JavaHelp tries to render these and I get a stream of text - obviously the mime type is not being picked up and the file is being treated as an html.
I have read about the setKeyData etc. methods which can be used to register a different mime type to be handled with a specified viewer.
My question is:
Is it simply a matter of calling the method, setKeyData to tell the HelpSet that a file of mime type pdf is to be handled by a viewer, such as Acrobat? If so has anyone done this?
Any help is greatly appreciated.
Cheers
Aaron

Answer 1

Here is a simplier code variation that works (only) for applications started using Java Web Start.
import java.awt.event.ActionEvent;
import java.net.MalformedURLException;
import java.net.URL;
import javax.jnlp.BasicService;
public class HelpStartBrowser extends com.sun.java.help.impl.JHSecondaryViewer {
    BasicService bs = null;
    /** Creates new HelpStartBrowser */
    public HelpStartBrowser() {
        super();
        // if running from jnlp, then start browser will work
        try {
            // Lookup the javax.jnlp.BasicService object
            bs = (BasicService)javax.jnlp.ServiceManager.lookup("javax.jnlp.BasicService");
            if (!bs.isWebBrowserSupported()) bs = null;
        } catch (javax.jnlp.UnavailableServiceException ue) {
            bs = null;
    /** Called when item is clicked */
    public void actionPerformed(ActionEvent event) {
        String url = this.getContent();
        openBrowser(url);
    /** Use Java Web Start BasicService to start browser */
    private void openBrowser(String url) {
        try {
            if (bs != null)
                bs.showDocument(new URL(url));
        } catch (MalformedURLException me) {
}