Java window builder: runtime error

Question

I create very simple Gui using WindowBuilder plugin for Eclipse. I'm using Swing (maybe a problem?) I've got plenty of runtime errors:

Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: com/jgoodies/common/base/Preconditions
    at com.jgoodies.forms.layout.FormSpec.<init>(FormSpec.java:179)
    at com.jgoodies.forms.layout.ColumnSpec.<init>(ColumnSpec.java:147)
    at com.jgoodies.forms.layout.FormSpecs.<clinit>(FormSpecs.java:62)
    at com.jgoodies.forms.layout.LayoutMap.createRoot(LayoutMap.java:569)
    at com.jgoodies.forms.layout.LayoutMap.getRoot(LayoutMap.java:217)
    at com.jgoodies.forms.layout.ColumnSpec.decode(ColumnSpec.java:199)
    at it.myweb.project.GUI.TestGUI.initialize(TestGUI.java:50)
    at it.myweb.project.GUI.TestGUI.<init>(TestGUI.java:39)
    at it.myweb.project.GUI.TestGUI$1.run(TestGUI.java:26)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Caused by: java.lang.ClassNotFoundException: com.jgoodies.common.base.Preconditions
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 23 more

Code:

import java.awt.EventQueue;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

import com.jgoodies.forms.layout.ColumnSpec;
import com.jgoodies.forms.layout.FormLayout;
import com.jgoodies.forms.layout.RowSpec;

public class TestGUI {

    private JFrame frame;
    private JTextField textField;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    ChatGUI window = new ChatGUI();
                    window.frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the application.
     */
    public ChatGUI() {
        initialize();
    }

    /**
     * Initialize the contents of the frame.
     */
    private void initialize() {
        frame = new JFrame();
        frame.setBounds(100, 100, 1006, 737);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(new FormLayout(new ColumnSpec[] {
                ColumnSpec.decode("default:grow"),
                ColumnSpec.decode("right:max(50dlu;default)"),},
            new RowSpec[] {
                RowSpec.decode("fill:default:grow"),
                RowSpec.decode("bottom:max(30dlu;default)"),}));

        JTextArea textArea = new JTextArea();
        frame.getContentPane().add(textArea, "1, 1, 2, 1, fill, fill");

        textField = new JTextField();
        frame.getContentPane().add(textField, "1, 2, fill, center");
        textField.setColumns(10);

        JButton btnNewButton = new JButton("Invia");
        frame.getContentPane().add(btnNewButton, "2, 2, center, center");
    }
}

Please note that jgoodies is included in the referenced libraries.

Answer 1

Make sure the project contains both jgoodies-common-x.x.x.jar and jgoodies-forms-x.x.x.jar

If you create a new window project and add a jgoodies component to the UI you will get the jar file, then you can just copy it into your original project and reference it.

Answer 2

jgoodies jar should be included in runtime classpath of your application. You mention that is is included in referenced libraries, which presumably means that it is on compile classpath, but this is not enough. To include jar on runtime classpath use -cp switch when running java application with command line.

Answer 3

If your project is maven, it is better to add jgoodies as maven dependency:

<dependency>
    <groupId>com.jgoodies</groupId>
    <artifactId>jgoodies-forms</artifactId>
    <version>1.8.0</version>
</dependency>

This solve all problems.