NetBeans: Link Data with the User Interface using JavaBeans

The following is a brief description how a java bean can be linked with the UI using NetBeans:

Java Beans are Java objects (see Sun Website), which have a few unique characteristics:

  • have a default constructor without any arguments
  • have a number of properties, which are a set of variables and getter and setter methods (see NetBeans Tutorial).
  • implement property change listeners

The following is a simple example of a JavaBean:

/*
 * A simple JavaBean based on NetBeans tutorial.
 */

package de.mxro.textedit.gdocseditor.gui;

import java.beans.*;
import java.io.Serializable;

/**
 *
 * @author mx
 */
public class GDocsSettings implements Serializable {

    
    protected String password;

    /**
     * Get the value of password
     *
     * @return the value of password
     */
    public String getPassword() {
        return password;
    }

    /**
     * Set the value of password
     *
     * @param password new value of password
     */
    public void setPassword(String password) {
        this.password = password;
    }

    private PropertyChangeSupport propertySupport;

    public GDocsSettings() {
        propertySupport = new PropertyChangeSupport(this);
    }

    protected String username;

    /**
     * Get the value of username
     *
     * @return the value of username
     */
    public String getUsername() {
        return username;
    }

    /**
     * Set the value of username
     *
     * @param username new value of username
     */
    public void setUsername(String username) {
        this.username = username;
    }



    public void addPropertyChangeListener(PropertyChangeListener listener) {
        propertySupport.addPropertyChangeListener(listener);
    }

    public void removePropertyChangeListener(PropertyChangeListener listener) {
        propertySupport.removePropertyChangeListener(listener);
    }

}

A key disadvantage of JavaBeans is that it is quite time intensive to write their code; involving many repetitive tasks like writing getter and setter methods.

Luckily, NetBeans provides generators for generating JavaBeans code. Going through File/ New a new empty bean can be created.
bildschirmfoto2010-04-20um09-49-54.png
In the source code of the bean, using right-click and „insert code“ …

bildschirmfoto2010-04-20um09-51-33.png

… a new property can be added.
bildschirmfoto2010-04-20um09-53-23.png

bildschirmfoto2010-04-20um09-54-36.png

NetBeans further provides mechanisms to easily link these beans with user interfaces (Giudici java.net weblog, 2008). Furthermore, through these beans, the UI can be directly linked with databases (NetBeans Wiki).

Further Resources:

NetBeans Tutorial on GUI/Beans Binding
Java Tutorial on GUI/Beans Binding using NetBeans

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