如何将文本添加到 JFrame?

So I am designing a JFrame using Eclipse WindowBuilder. This specific frame is an error message stating that the user provided invalid credentials. I have added a button to exit the frame and I now need to display the actual error message "The login credentials specified are invalid. Please provide valid credentials."

I have done some searching and everyone says to use a JLabel, but when I create my JLabel and enter the text to it, there is no wordwrap or anything so I can't fit the label inside my frame.

What is an easy way to simply display a message in the center of the JFrame?

解决方案

To create a label for text:

JLabel label1 = new JLabel("Test");

To change the text in the label:

label1.setText("Label Text");

And finally to clear the label:

label1.setText("");

And all you have to do is place the label in your layout, or whatever layout system you are using, and then just add it to the JFrame...