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Jan 27th, 2010, 10:10 AM
#1
Thread Starter
New Member
ArrayList overwriting entries
Hi Guys,
i'm creating an Java app to add 2 different String values to an ArrayList ( it has to do with my Hobby Badminton )
I now have to following code below:
Code:
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Collections;
import javax.swing.*;
public class Badminton implements ActionListener {
JButton knop1;
JTextField tekstvak1;
JTextField tekstvak2;
JTextField tekstvak3;
JTextArea uitvoer;
JButton toernooiButton;
JButton exitButton;
JButton zoekButton;
JButton wisButton;
ArrayList<String> array1;
ArrayList<String> array2;
private JPanel getContent()
{
JLabel title = new JLabel ("Badminton Toernooien");
JPanel bannerpanel = new JPanel();
bannerpanel.setSize(300,50);
bannerpanel.add(title);
JLabel toernooiplek = new JLabel("Toernooi plek: ");
tekstvak1 = new JTextField(30);
JPanel plekPanel = new JPanel();
plekPanel.setLayout(new BoxLayout(plekPanel, BoxLayout.X_AXIS));
plekPanel.setSize(200, 20);
plekPanel.add(toernooiplek);
plekPanel.add(tekstvak1);
JLabel toernooinaam = new JLabel ("Toernooi naam: ");
tekstvak2 = new JTextField(30);
JPanel tekstPanel = new JPanel();
tekstPanel.setLayout(new BoxLayout(tekstPanel, BoxLayout.X_AXIS));
tekstPanel.setSize(200,20);
tekstPanel.add(toernooinaam);
tekstPanel.add(tekstvak2);
JPanel blankPanel = new JPanel();
blankPanel.setLayout(new BoxLayout(blankPanel, BoxLayout.X_AXIS));
blankPanel.setSize(200,20);
toernooiButton = new JButton("Voeg toernooi toe");
exitButton = new JButton("Afsluiten");
zoekButton = new JButton("Geef Toernooien weer");
wisButton = new JButton("Wis invoer");
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.X_AXIS));
buttonPanel.add(toernooiButton);
buttonPanel.add(exitButton);
buttonPanel.add(zoekButton);
buttonPanel.add(wisButton);
toernooiButton.addActionListener(this);
exitButton.addActionListener(this);
zoekButton.addActionListener(this);
wisButton.addActionListener(this);
JPanel mainPanel = new JPanel();
System.out.println("JPanel default layout manager = " +
mainPanel.getLayout().getClass().getName());
mainPanel.add(title);
mainPanel.add(tekstPanel);
mainPanel.add(plekPanel);
mainPanel.add(blankPanel);
mainPanel.add(buttonPanel);
return mainPanel;
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource() == toernooiButton){
String plek = tekstvak1.getText();
String naam = tekstvak2.getText();
tekstvak1.setText("");
tekstvak2.setText("");
array1 = new ArrayList<String>();
array1.add(plek);
array2 = new ArrayList<String>();
array2.add(naam);
Collections.sort(array1);
Collections.sort(array2);
JOptionPane.showMessageDialog(null, "Toernooi Toegevoegd");
}
if (ae.getSource()== wisButton){
tekstvak1.setText("");
tekstvak2.setText("");
}
if (ae.getSource()== zoekButton){
System.out.println(array1);
}
if(ae.getSource()== exitButton){
System.exit(0);
}
}
public static void main(String[] args) {
Badminton app = new Badminton();
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(app.getContent());
f.setSize(800,600);
f.setLocation(200, 200);
}
}
The problem is that when i want to show the current ArrayList with the "zoekButton" it will give me my last entered input. How can i fix this so that it will list my whole ArrayList?
Thanks in advance
Tom
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Jan 27th, 2010, 11:20 AM
#2
Re: ArrayList overwriting entries
Every time you click your button you're re-initializing your ArrayList.
Code:
array1 = new ArrayList<String>();
array1.add(plek);
array2 = new ArrayList<String>();
array2.add(naam);
Move the array1/2 = new ArrayList<String>(); to where you're declaring the list instead.
change
Code:
ArrayList<String> array1;
ArrayList<String> array2;
to
Code:
ArrayList<String> array1 = new ArrayList<String>();
ArrayList<String> array2 = new ArrayList<String>();
and then change the first bit of code to
Code:
array1.add(plek);
array2.add(naam);
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Jan 27th, 2010, 12:16 PM
#3
Thread Starter
New Member
Re: ArrayList overwriting entries
Hi kfcSmitty,
I just opened up Eclipse again to adjust it. I tested the code again before adjusting it and i got this error:
Unable to create editor ID org.eclipse.jdt.ui.ClassFileEditor: The Class File Viewer cannot handle the given input
Code:
package Final;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Collections;
import javax.swing.*;
public class Badminton implements ActionListener {
JButton knop1;
JTextField tekstvak1;
JTextField tekstvak2;
JTextField tekstvak3;
JTextArea uitvoer;
JButton toernooiButton;
JButton exitButton;
JButton zoekButton;
JButton wisButton;
ArrayList<String> array1 = new ArrayList<String>();
ArrayList<String> array2 = new ArrayList<String>();
private JPanel getContent()
{
JLabel title = new JLabel ("Badminton Toernooien");
JPanel bannerpanel = new JPanel();
bannerpanel.setSize(300,50);
bannerpanel.add(title);
JLabel toernooiplek = new JLabel("Toernooi plek: ");
tekstvak1 = new JTextField(30);
JPanel plekPanel = new JPanel();
plekPanel.setLayout(new BoxLayout(plekPanel, BoxLayout.X_AXIS));
plekPanel.setSize(200, 20);
plekPanel.add(toernooiplek);
plekPanel.add(tekstvak1);
JLabel toernooinaam = new JLabel ("Toernooi naam: ");
tekstvak2 = new JTextField(30);
JPanel tekstPanel = new JPanel();
tekstPanel.setLayout(new BoxLayout(tekstPanel, BoxLayout.X_AXIS));
tekstPanel.setSize(200,20);
tekstPanel.add(toernooinaam);
tekstPanel.add(tekstvak2);
JPanel blankPanel = new JPanel();
blankPanel.setLayout(new BoxLayout(blankPanel, BoxLayout.X_AXIS));
blankPanel.setSize(200,20);
toernooiButton = new JButton("Voeg toernooi toe");
exitButton = new JButton("Afsluiten");
zoekButton = new JButton("Geef Toernooien weer");
wisButton = new JButton("Wis invoer");
JPanel buttonPanel = new JPanel();
buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.X_AXIS));
buttonPanel.add(toernooiButton);
buttonPanel.add(exitButton);
buttonPanel.add(zoekButton);
buttonPanel.add(wisButton);
toernooiButton.addActionListener(this);
exitButton.addActionListener(this);
zoekButton.addActionListener(this);
wisButton.addActionListener(this);
JPanel mainPanel = new JPanel();
System.out.println("JPanel default layout manager = " +
mainPanel.getLayout().getClass().getName());
mainPanel.add(title);
mainPanel.add(tekstPanel);
mainPanel.add(plekPanel);
mainPanel.add(blankPanel);
mainPanel.add(buttonPanel);
return mainPanel;
}
public void actionPerformed(ActionEvent ae){
if(ae.getSource() == toernooiButton){
String plek = tekstvak1.getText();
String naam = tekstvak2.getText();
tekstvak1.setText("");
tekstvak2.setText("");
array1 = new ArrayList<String>();
array1.add(plek);
array2 = new ArrayList<String>();
array2.add(naam);
Collections.sort(array1);
Collections.sort(array2);
JOptionPane.showMessageDialog(null, "Toernooi Toegevoegd");
}
if (ae.getSource()== wisButton){
tekstvak1.setText("");
tekstvak2.setText("");
}
if (ae.getSource()== zoekButton){
System.out.println(array1);
}
if(ae.getSource()== exitButton){
System.exit(0);
}
}
public static void main(String[] args) {
Badminton app = new Badminton();
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.getContentPane().add(app.getContent());
f.setSize(800,600);
f.setLocation(200, 200);
}
}
I changed the code in my Badminton class to
Code:
ArrayList<String> array1 = new ArrayList<String>()
ArrayList<String> array2 = new ArrayList<String>();
but i don't know exactly where i need to put the
Code:
array1 = new ArrayList<String>();
array1.add(plek);
array2 = new ArrayList<String>();
array2.add(naam);
I understand now what the problem is , but not totally how i need to fix it.
Thanks for your fast response
Tom
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Jan 27th, 2010, 01:07 PM
#4
Re: ArrayList overwriting entries
This code
Code:
array1 = new ArrayList<String>();
array1.add(plek);
array2 = new ArrayList<String>();
array2.add(naam);
Is already in your program, if you search for it, you'll find it. What you need to do, is remove these two lines from the above code
Code:
array1 = new ArrayList<String>();
array2 = new ArrayList<String>();
Which will leave you with
Code:
array1.add(plek);
array2.add(naam);
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Jan 27th, 2010, 01:49 PM
#5
Thread Starter
New Member
Re: ArrayList overwriting entries
ah ok fixed it now, but the program won't start because of that error:
The Class File Viewer cannot handle the given input ('org.eclipse.ui.ide.FileStoreEditorInput').
Do you know how to fix that error, didn't had it before
Thanks for the fast feedback
Tom
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Jan 27th, 2010, 02:00 PM
#6
Thread Starter
New Member
Re: ArrayList overwriting entries
ok i fixed that error by putting in
Code:
f.setVisible(true);
But no i get this when i click the toernooiButton:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Final.Badminton.actionPerformed(Badminton.java:94)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)
Last edited by tommie20; Jan 27th, 2010 at 02:00 PM.
Reason: typo
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Jan 27th, 2010, 02:15 PM
#7
Thread Starter
New Member
Re: ArrayList overwriting entries
Ok,
the problem is this piece of code
Code:
array1.add(plek);
array2.add(naam);
if i delete it it runs, but not properly.
Do you know where i need to put it / change it.
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Jan 27th, 2010, 02:21 PM
#8
Thread Starter
New Member
Re: ArrayList overwriting entries
ok guys,
solved the problem, it was the start of the code.
The lines
Code:
ArrayList<String> array1 = new ArrayList<String>();
ArrayList<String> array2 = new ArrayList<String>();
I forgot those.
kfcSmitty, thanks for your help
Tom
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