Here you can find the source of restoreFrame(JFrame frame)
public static void restoreFrame(JFrame frame)
//package com.java2s; //License from project: Open Source License import java.awt.IllegalComponentStateException; import javax.swing.JFrame; public class Main { public static void restoreFrame(JFrame frame) { try {//from w ww . ja va 2s . com frame.setExtendedState(JFrame.NORMAL); } catch (IllegalComponentStateException e) { // ignore } } }