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Update jtextfields in jpanel when other jtextfields changed

i have a GUI with some jtextfields (for example jtextfield_a, jtextfield_b, jtextfield_c, jtextfield_d, jtextfield_e). I can't find a way to change the value of jtextfield_d and jtextfield_e when for example jtextfield_a value is changed. Any way to do this?

You could...
Use an ActionListener on the JTextField you want to monitor
See How to Write an Action Listener for more details
Cons
Requires the user to press the "action" key (typically Enter) while the field is focused
You could...
Use a FocusListener on the JTextField you want to monitor
Cons
Requires the user to leave the field, so the focusLost event can be triggered
See How to Write a Focus Listener for more details
You could...
Use a DocumentListener on the JTextField you want to monitor
See How to Write a Document Listener for more details
Pros
Provides real time feedback as the user types
You could...
Have some other control trigger the update, like a JButton, so the user gains greater control over the process. It's not always the best from the users perspective (because we're lazy), but is among the simplest

Swing Dynamical JCombobox detect selection change by user

I would like to know if there is a way to detect if changes in the selection of a item in a swing JCombobox is done by a user (actively) or is causes by repopulating the Jcombobox.
I have to dynamically repopulate the items of the combobox based on other selection, this also invokes the actionPerformed event
so actionPerformed is invoked by:
selection changed by user
repopulating the jcombobox items.
how to tell the difference?
Thanks of helping !

No, not really.
A possible solution is to disable event notification while the combo box is updated. This can be done in (at least) one of two ways...
Firstly, you could physically remove the listener from the combo box, if you have a reference to it.
Secondly, you set a boolean flag, which when true, the listener would ignore the event.
For example...

How to transfer focus a custom component when traversal keys are disabled?

I have created a custom JComboBox with a custom popup that implements the KeyListener. I wanted an item to be selected from the popup of the cmbBox on the press of either Tab or Enter hence I set the setFocusTraversalKeysEnabled(false) for both the combobox and the popup.
The problem with this approach is that now I have to add another KeyListener to the combobox when I use it in containers so as to shift the focus.
Can I fire a transfer focus event(hypothetically) or something like that within my custom JComponent which will transfer the focus in its parent component so that I dont have to add key listeners everywhere I use it. I have used transferFocus() but it is not transferring the focus.
I have not dirtied my hands on Key Bindings yet but is there a key binding to transfer the focus?
Thanks
I am trying to recreate a sscce but its proving difficult. Please bear.

Basic Listeners lifecycle is about to add required listener if is really needed, and remove Listener if is useless
I'd would be suggesting use KeyBindings, because this Listener is designated for Swing JComponents and sure you can (sure same as for KeyListener) add this listener to the concrete JComponent or its derivate(s)
you can add Listener to the derived popup on firePopupMenuWillBecomeVisible
you can add ItemListener to the derived JList
maybe not correct way but protect all defects implemented to the KeyListener, that only Focus owner can take events from keyboard, sure workaround for KeyBindings os more that settable and confortable
notice please read this answer

How to avoid infinite update loops in Swing?

I have a JPanel with a set of items (for example combo boxes and text fields). Some action listeners are implemented on those items to register user updates.
If the user selects a value in a JComboBox (for example), the action listener captures the event. The corresponding underlying bean method is called and the panel is refreshed. Changing can have an impact on other fields displayed in the pane.
The problem is that when the panel is refreshed, all listeners are triggered, and they call for a refresh themselves. This leads to an infinite loop.
How can I avoid this? I can't get rid of the listeners, because I need to capture user updates, but I don't want these to fire when I am only refreshing the panel content.

One option is to have a central boolean value or some indicator that each listener can check to prevent the chaining of events.
Another option is to not refresh the field if the value does not change. That way each component is updated at most once per refresh.

I can't get rid of the listeners, because I need to capture user updates, but I don't want these to fire when I am only refreshing the pane content
Then remove the listeners, refresh the pane content and then restore the listeners. This way the listeners only fire when a user change is made.

I think that if your problem is in combobox it just points to a bug. Really, if user changes the value of the combobox, that somehow triggers refresh of the pane the value of the combo box should not be changed second time! So if it is onValueChanged() (or something like this) it should not be called at all when pane is being refreshed.
But if for some reason it happens you can verify whether the old and new values are the same and exit the listener.
If this still does not help I'd suggest you some non-standard solution: try to investigate the stack trace into the listener. Can you identify whether the listener was called as a direct reaction to user's action or after the pane refresh? In this case you can create utility method and put it in the beginning of all relevant listeners.

My applications also suffered from this problem, and solution with the flag, that I should check in every listener and enable/disable in code, feels not very good for me. I always forgot to set this flag to true/false in necessary places.
That is why I decide to implement another solution.
I just subclass all default swing components that I am using often, and implemented custom ValueChanged event that I fire after mouse/keyboard/clipboard/etc events. Now I am always know, that if ValueChanged event is fired, it means, that value was issued by user, not by code. Event handling in this way much more cleaner. This solution solves my problem.

Java Swing and JComboBox Events

I have a JComboBox with multiple values in it. I need to be able to detect when the user clicks the JComboBox but does not change the currently selected item.
Neither itemStateChanged nor actionPerformed fire when this happens.
What event should I be using?

How about recording the combo box's state when the mouse button is pressed, and comparing it to the value the box has when the mouse button is released?
attach a MouseListener to the JComboBox
override the mousePressed() method to record the box's state to a temp variable
override the mouseReleased() method to compare the box's value to the temp variable's value
At this point, it's a simple equality check.

Add a MouseListener to the JComboBox using its addMouseListener method. You will want to extend MouseAdapter and override only the mouseClicked method.

What if the user users the keyboard to open the popup and then uses the escape key to close the popup?
I would use a PopupMenuListener. This should handle both mouse and keyboard actions. The concept would be the same as other suggestions. When the popup is displayed you save the selected index. When is closes you compare the selected index to see it it has changed.

I was looking specifically at right mouse click on items, so it's a slightly different problem.
But the solution for me was to
Subclass JComboBox substituting getCellRenderer() with a subclassed DefaultListCellRenderer.
In the cell renderer intercept getListCellRendererComponent() which has boolean isSelected, boolean cellHasFocus parameters and can be used to watch for mouse events and do list.setToolTipText().
I'm sure the non-final selection change will get there, where it can be intercepted.