adding data to JTable

[hafezdivandari]

hi, How can I write this code to add any data in user[] to the JTable named userTable?

userTable.setModel( new DefaultTableModel(
                new Object [][] {
                    {user[0].getId(), user[0].getName(), user[0].getUserName(), user[0].getPassword()},
                    {user[1].getId(), user[1].getName(), user[1].getUserName(), user[1].getPassword()},
                    {user[2].getId(), user[2].getName(), user[2].getUserName(), user[2].getPassword()} 
                },
                new String [] {
                    "ID", "Name", "Username", "Password"
                }
            ));

it should look like this, but it doesn't work? :(

userTable.setModel( new DefaultTableModel(
                new Object [][] {
                    {user[].getId(), user[].getName(), user[].getUserName(), user[].getPassword()}
                },
                new String [] {
                    "ID", "Name", "Username", "Password"
                }
            ));

[Fubarable]

Let's try to clarify the problem first.

Are you trying to add a row of data to an existing JTable, one that already displays data?
If so, then don't try to add anything to the JTable itself, but instead create a DefaultTableModel field that the JTable uses as its model, and add a row to this model via its addRow(...) method.

If this is not what you're trying to do, then please clarify the problem for us.

[hafezdivandari]

I want to create a JTable that has 4 column and uncertain number of rows which is related to length of user[] Array, first column should show user[].getId(), second column shows user[].getName(), 3rd column user[].getUsername() and last one should show user[].getPassword(). how can I create its Model?

[Fubarable]

One way is to create a DefaultTableModel using the constructor that takes an array of Column names and an int for row count, and pass in your array of four column Strings, and 0 for the row count. Then using a for loop, loop through your user array and inside the loop create an array of 4 objects:

Object[] row = new Object[4];

Then fill the array with the current user object, placing the appropriate field of the object into the appropriate array item, and then call addRow on your DefaultTableModel, adding your row. So in pseudocode:

create DefaultTableModel passing in a String array of column names and 0 for row count of 0.
for each User in my users array
   create an array of Object[4] called row
   fill this array with item's from the ith User
   call addRow on my table model and pass in my row Object array.
end for

Create your JTable and use this model as the table's model.

[DarrylBurke]

You could check out camickr's Bean Table Model.

db

[hafezdivandari]

I Wrote this code, But it doesn't work, I mean the constructor works and add the first row but addRow() method in the for loop doesn't work and throws exception.

         JTable userTable = new JTable();
         DefaultTableModel tableModel = new DefaultTableModel(
                new String [] {
                    "ID", "Name", "Username", "Password"
                }, 0);
            
            for (int i = 0; i < ShopStoreInfo.user.length ; i++) {
                tableModel.addRow(new Object [] {
                   user[i].getId(), user[i].getName(), user[i].getUsername(), user[i].getPassword()
                });
            }
            
            userTable.setModel(tableModel);

[Fubarable]

It's *always* a good idea when you get an exception or compilation error to post the full text of the error or exception and indicate which line is causing it. Else we have to guess, and our track record for guessing isn't so good.

[DarrylBurke]

I... throws exception.

When seeking help with an error or exception, post the entire error message or stack trace. Why should people have to guess at relevant information that is available with you?

db

edit Did I really take >6 minutes to read and respond to a PM? Guess I did.

[hafezdivandari]

Here is the entire exception. (the 915 line is the line that addRow() method performs).

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
	at AdminControlPanel$2.<init>(ShopStore.java:915)
	at AdminControlPanel.<init>(ShopStore.java:894)
	at SignIn$1.actionPerformed(ShopStore.java:150)
	at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
	at javax.swing.AbstractButton$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:6463)
	at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
	at java.awt.Component.processEvent(Component.java:6228)
	at java.awt.Container.processEvent(Container.java:2213)
	at java.awt.Component.dispatchEventImpl(Component.java:4819)
	at java.awt.Container.dispatchEventImpl(Container.java:2271)
	at java.awt.Component.dispatchEvent(Component.java:4645)
	at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4816)
	at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4476)
	at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4406)
	at java.awt.Container.dispatchEventImpl(Container.java:2257)
	at java.awt.Window.dispatchEventImpl(Window.java:2677)
	at java.awt.Component.dispatchEvent(Component.java:4645)
	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)

[Fubarable]

You are using the tableModel variable inside of its anonymous inner class. Don't do that. Make the TableModel object and then have your for loop after the anonymous class code.

[hafezdivandari]

Thank you!

[Fubarable]

You're welcome!