Question

I have two JLists.

List A has these elements:

• 1
• two
• 78
• item4

List B that is for now empty.

My frame has these two list and a button Verify. Once I click on the button, the selected item of List A gets verified whether it is an integer. If so, the selected item has to be transfered to List B and removed from List A.

What I did so far is when clicking on the button, the item get copied but once I selected another item the previous one get replaced with the new item which I don’t want.

How can transfer (append) the item to the other list and remove it from the first one, this way I have got finally the list with all the items without being replaced by the new items.

Answer 1

Use a DefaultListModel.

DefaultListModel dlmA = new DefaultListModel(); // For list A
dlmA.addElement(1);
dlmA.addElement("two");
dlmA.addElement(78);
dlmA.addElement("item4");

listA.setModel(dlmA);

Now, the same for your list B.

DefaultListModel dlmB = new DefaultListModel(); // For list B
listB.setModel(dlmB);

If you want to add items to your second list, just add them to the DefaultListModel dlmB. This means you have to keep a reference to dlmB in your working class, this way you can add elements to it inside the ActionListener of your button.

public void actionPerformed(ActionEvent evt)
{
    // Perform your checks. If you want to add it to list B, use:
    dlmB.addElement(yourNewElem);
}