How do I use Java Swing in Eclipse on Mac OS X?

Question

I am new to Mac OS X and is using version 10.6.5. JDK 1.6_u22 seems to be preinstalled on the system. I have downloaded Eclipse 3.5.2.

It works fine if I create a simple hello world, but I can not import JFrame or use Swing. The error message that I get is:

Access restriction: The type JFrame is not accessible due to restriction on required library /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Classes/classes.jar

Here is the simple program that I have tried with:

import javax.swing.JFrame;
public class Test {
    public static void main(String[] args) {
        new JFrame();
    }
}

How do I use Java Swing in Eclipse on Mac OS X?

Solution

On Mac OS X 10.5.8, Eclipse 3.4.2 and Xcode 3.1.4, the example below builds and runs using recent revisions of either Java 1.5 or Java 1.6. As Xcode includes the JDK, what version of Mac OS X and Xcode are you using?

Also verify that your Swing project hasn't inadvertently included SWT.

Addendum: Check these two dialogs:

Eclipse > Preferences > Java > Build Path
Eclipse > Preferences > Java > Installed JREs

You should see references to /System/Library/Frameworks/JavaVM.framework/.

import javax.swing.*;
import java.awt.*;
import java.awt.geom.*;
public class X {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new JPanel() {
            private final int SIZE = 200;
            private final int INSET = 20;
            @Override
            public Dimension getPreferredSize() {
                return new Dimension(SIZE, SIZE);
            }
            @Override
            public void paintComponent(Graphics g) {
                super.paintComponent(g);
                Graphics2D g2 = (Graphics2D) g;
                g2.setColor(Color.blue);
                Line2D line1 = new Line2D.Double(INSET, INSET,
                    getWidth() - INSET, getHeight() - INSET);
                Line2D line2 = new Line2D.Double(getWidth() - INSET,
                    INSET, INSET, getHeight() - INSET);
                g2.setStroke(new BasicStroke(16,
                    BasicStroke.CAP_ROUND,
                    BasicStroke.JOIN_BEVEL));
                g2.draw(line1);
                g2.draw(line2);
            }
        });
        frame.pack();
        frame.setVisible(true);
    }
}

Comments

[Mot]

Unfortunately, I can't help you with Eclipse, because I'm using a real Java-IDE: IntelliJ. ;) What happens if you try to launch it from command line?

[David Gelhar]

Similar to stackoverflow.com/questions/860187/…

[Mot]

Did you post the entire Test class? Are you using the empty package or maybe package javas.swing;?

[David Gelhar]

@Jonas the answer to that question suggests that the error message can result from a jar file in your classpath that's trying to replace a standard class.

[Jonas]

@David: I don't understand how that question help me. JFrame is a standard class in Java SE.

[Jonas]

@mklhmnn: yes, it's the entire program. I get the same error if I use package com.example.

[Jonas]

I'm using Xcode 3.2.5. The computer is brand new and I have updated all software.

[Jonas]

Under Eclipse > Preferences > Java > Installed JREs the JVM 1.4 was selected, I selected JVM 1.6.0 instead and created a new project. Now is it working. Thanks.