[Java]JOptionPane

[nicola]

end scusami ma mi dici dove metterla la stringa che mi hai dato perchè come m l'hai data tu nn va... e nn so come aggiustarla...
scusami!!!

[andbin]

Originariamente inviato da nicola
end scusami ma mi dici dove metterla la stringa che mi hai dato perchè come m l'hai data tu nn va... e nn so come aggiustarla...

getAppletContext() va invocato su un oggetto Applet. Ora .. se usare implicitamente il 'this' o un riferimento esplicito alla tua Applet, dipende ovviamente da dove metti questa invocazione.

[nicola]

ho fatto così....

if (evt.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
				                {
				                    //JOptionPane.showMessageDialog ((Component) evt.getSource (), evt.getDescription ());
				                	Applet f = new Applet();
				                	try {
										f.getAppletContext().showDocument (new URL ("help.html#CreaConto"));
									} catch (MalformedURLException e) {
										// TODO Auto-generated catch block
										e.printStackTrace();
									}
				                }

mi genere l'eccezione
Exception occurred during event dispatching:
java.lang.NullPointerException
at java.applet.Applet.getAppletContext(Unknown Source)
at gccbClient.Frame$16$1.hyperlinkUpdate(Frame.java:1 377)
at javax.swing.JEditorPane.fireHyperlinkUpdate(Unknow n Source)
at javax.swing.text.html.HTMLEditorKit$LinkController .activateLink(Unknown Source)
at javax.swing.text.html.HTMLEditorKit$LinkController .mouseClicked(Unknown Source)
at java.awt.AWTEventMulticaster.mouseClicked(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent( Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(U nknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unkno wn Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(U nknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(U nknown Source)
at java.awt.Dialog$1.run(Unknown Source)
at java.awt.Dialog$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Dialog.show(Unknown Source)
at javax.swing.JOptionPane.showOptionDialog(Unknown Source)
at javax.swing.JOptionPane.showMessageDialog(Unknown Source)
at javax.swing.JOptionPane.showMessageDialog(Unknown Source)
at javax.swing.JOptionPane.showMessageDialog(Unknown Source)
at gccbClient.Frame$16.actionPerformed(Frame.java:139 0)
at javax.swing.AbstractButton.fireActionPerformed(Unk nown Source)
at javax.swing.AbstractButton$Handler.actionPerformed (Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed (Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseRe leased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent( Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(U nknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unkno wn Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilter s(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(U nknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarch y(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

[andbin]

Originariamente inviato da nicola
Applet f = new Applet();

Ma perché vuoi creare un oggetto Applet?? Non hai un reference al tuo Applet??

[nicola]

si hai ragione... la classe dove c'è l'init del mio applet è CCCLientApplet.
ho fatto allora

if (evt.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
{
//JOptionPane.showMessageDialog ((Component) evt.getSource (), evt.getDescription ());
CCClientApplet f = new CCClientApplet();
try {
File g = new File("help.html");
System.err.println(g.exists());
f.getAppletContext().showDocument (new URL ("help.html"));
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
.printStackTrace();
}
}

ma mi genere sempre nullpointerexception

[andbin]

Originariamente inviato da nicola
si hai ragione... la classe dove c'è l'init del mio applet è CCCLientApplet.
ho fatto allora

CCClientApplet f = new CCClientApplet();

ma mi genere sempre nullpointerexception

No, non va bene (e non ha senso) creare una nuova istanza di Applet o della tua classe che estende Applet.
Cerca di passare, in qualche modo, la istanza che hai già della tua Applet.

Un semplice esempio (giusto per farti capire):

import java.applet.*;
import java.net.*;
import javax.swing.*;
import javax.swing.event.*;

public class AppletInfo extends JApplet
{
    public void init ()
    {
        JEditorPane editorPane = new JEditorPane ("text/html", "Vai su Google");
        editorPane.setEditable (false);
        editorPane.addHyperlinkListener (new MyLinkListener (getAppletContext ()));

        JOptionPane.showMessageDialog (null, editorPane);
    }
}


class MyLinkListener implements HyperlinkListener
{
    private AppletContext appletCtx;

    public MyLinkListener (AppletContext appletCtx)
    {
        this.appletCtx = appletCtx;
    }

    public void hyperlinkUpdate (HyperlinkEvent evt)
    {
        if (evt.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
        {
            try {
                appletCtx.showDocument (new URL (evt.getDescription ()));
            } catch (Exception e) { }
        }
    }
}

Nota le parti in rosso. Viene fatto in modo che la classe MyLinkListener possa ricevere e usare il "contesto" AppletContext.

[Alex'87]

Mi intrometto:

Non c'e' proprio modo di rendere cliccabile un link in un una JLabel con html? Vorrei rendere cliccabile il link al mio sito nell'about del programma ma i JLabel non hanno un HyperlinkListener