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javaswingjtextfield

Retrieving text from a JTextField and storing in another class's object


I'm currently working on a GUI based application and am using the code-generation feature of netbeans 7.1 along with some custom code of my own to make life easier for me.

What I have is an array of JTextboxes from which I need to retrieve the Text and store in the respective object from an array of objects of a different class.

The problem is that I'm receiving several runtime exceptions after submitting the data.

Here's some relevant snippets of my code:

My custom code for component creation :

plnlabel = new javax.swing.JLabel[3];
plntext = new javax.swing.JTextField[3];
int i;
for(i=0;i<3;i++)
{
    plnlabel[i] = new JLabel("Player "+(i+1)+": ");
    plnlabel[i].setVisible(false);
    plntext[i] = new JTextField("Player"+(i+1)+" Name");
    plntext[i].setVisible(false);
}

I have 3 public data members

public int plnum;
public int size;
public Player [] players;

Now here's the code for the submit button that triggers the exceptions:

 private void namesubActionPerformed(java.awt.event.ActionEvent evt)                                        
{                                            
    plnum = nop.getSelectedIndex()+1;
    namesub.setVisible(false);
    customizelabel.setVisible(true);
    plnamelabel.setVisible(false);
    int i;
    for(i=0;i<plnum;i++)
    {
        plnlabel[i].setVisible(false);
        plntext[i].setVisible(false);
        players[i].setName(plntext[i].getText());
    }
    sizeb.setVisible(true);
    sizesel.setVisible(true);
    sizesub.setVisible(true);
    pack();
}

And here's the huge list of exceptions :

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at snakesnladders.SnakesnLadders.namesubActionPerformed(SnakesnLadders.java:146)
    at snakesnladders.SnakesnLadders.access$000(SnakesnLadders.java:12)
    at snakesnladders.SnakesnLadders$1.actionPerformed(SnakesnLadders.java:86)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2713)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:707)
    at java.awt.EventQueue.access$000(EventQueue.java:101)
    at java.awt.EventQueue$3.run(EventQueue.java:666)
    at java.awt.EventQueue$3.run(EventQueue.java:664)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:680)
    at java.awt.EventQueue$4.run(EventQueue.java:678)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:677)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:211)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:128)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:117)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:113)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

I can't figure out what's wrong with my code. Did some trial and error and the only thing I came up with is that if I store the getText() data in a local variable in the button click event method, then there's no error.

I can basically print the getText() data but can't store it in the data member players[].

Anyone know something about this?


Solution

  • Add

    players[i] = new Player();

    Just before using players[i]