java super() main class

trscookie · 09-25-2007, 04:59 PM

Hello all,

I know that there are probably a million posts about this however I can not find any that can answer my question.

I have two forms in Netbeans( Java ) one of the frames loads up another to enter a text address but the information is not passed back to the main form.

I have tried to use the super() function but it just passes a NullPointerException. I think that I'm close but haven't quite got it:

main.java:

Code:

public class main extends javax.swing.JFrame 
{   

    private winTwo           winTwo      = new winTwo();


    public main() 
    {
        
        super( "main" );
        
        initComponents();
        
        
    }


    private void initComponents() 
    {

        // some generic components

    }

    
    private void button(java.awt.event.ActionEvent evt) 
    {

        winTwo ss = new winTwo( this );
        
        ss.main( null );

    }    


    public void setName( String name )
    {

        System.out.println( "Set name: " + name );

    }


}

winTwo.java:

Code:

public class serverSettings extends javax.swing.JFrame 
{
    
    private static helpClient              parent      = null;

    
    public serverSettings( JFrame parent, String s )
    {
        
        super( s );
        
        initComponents();
        
    }
    
    
    public serverSettings( JFrame parent )
    {
        
        super();
        
    }


    private void btnAccept(java.awt.event.ActionEvent evt) 
    {                                          
        
        parent.setName( "Hello World" );
        
    }      



    public static void main( String args[] )
    {
        
        java.awt.EventQueue.invokeLater( new Runnable() 
        {
            
            public void run() 
            {
                
                main Main = new main( parent );
                
                Main.setVisible( true );
                
            }
            
        } );
}

trscookie · 09-26-2007, 02:10 PM

there have got to be some java programmers out there

trscookie · 09-26-2007, 05:34 PM

here is a better example:

Code:

package multiForm;



public class frameOne extends javax.swing.JFrame 
{
    
    private static frameTwo two     = new frameTwo();
    
    
    
    public frameOne() 
    {
    
        initComponents();
        
    }
    
    
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        jButton1 = new javax.swing.JButton();
        jLabel1 = new javax.swing.JLabel();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jButton1.setText("Click Me!");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        jLabel1.setText("Should Change");

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
                    .addComponent(jLabel1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(jButton1, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel1)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 20, Short.MAX_VALUE)
                .addComponent(jButton1)
                .addContainerGap())
        );
        pack();
    }// </editor-fold>//GEN-END:initComponents
    
    
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        
        two.setVisible( true );
        
    }//GEN-LAST:event_jButton1ActionPerformed
    
    
    public static void main( String args[] ) 
    {
        
        java.awt.EventQueue.invokeLater( new Runnable() 
        {
            
            public void run() 
            {
                
                new frameOne().setVisible( true );
                
            }
            
        } );
    }
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JLabel jLabel1;
    // End of variables declaration//GEN-END:variables
    
}

Code:

package multiForm;



public class frameTwo extends javax.swing.JFrame 
{
    
    
    public frameTwo() 
    {
        
        initComponents();
        
    }
    
    
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">//GEN-BEGIN:initComponents
    private void initComponents() {
        jTextField1 = new javax.swing.JTextField();
        jButton1 = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jTextField1.setText("Set label on frame one");

        jButton1.setText("send text");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jTextField1, javax.swing.GroupLayout.DEFAULT_SIZE, 376, Short.MAX_VALUE)
                    .addComponent(jButton1, javax.swing.GroupLayout.Alignment.TRAILING))
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jButton1)
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
        );
        pack();
    }// </editor-fold>//GEN-END:initComponents

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
        
        String s = jTextField1.getText();
        
        
        // the string should be sent to the first class and set the label here
        // i have tried to used the functions super and parent but i cant get them to work :(
        
        
        this.dispose();
        
    }//GEN-LAST:event_jButton1ActionPerformed
    
    
    public static void main( String args[] ) 
    {
        
        java.awt.EventQueue.invokeLater( new Runnable() 
        {
            
            public void run() 
            {
                
                new frameTwo().setVisible( true );
                
            }
            
        } );
        
    }
    
    // Variables declaration - do not modify//GEN-BEGIN:variables
    private javax.swing.JButton jButton1;
    private javax.swing.JTextField jTextField1;
    // End of variables declaration//GEN-END:variables
    
}