Remove white outline JFrame

I have JFrame with a JTextPane in it. Kind of a very simple text editor. Now the problem is there is a very thin white border around the frame. This is ok if the color of the text pane is white but if …

Issue when adding two JPanels

I’m trying to add two JPanels to a JFrame, one with a simple backround and another one with buttons etc. Either I get only buttons or only the background. I can’t find a solution to my problem …

traverse an array in GUI Java

I am doing a questionnaire with questions and written answers. I need that when adding the answer, press the main button, tell me if it is correct or not and show me the other question of the array, …