Here you can find the source of value(JTextComponent txt)
public static String value(JTextComponent txt)
//package com.java2s; /*//from w w w . j ava 2s. c om * Copyright (c) 2016 Vivid Solutions. * * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * and Eclipse Distribution License v. 1.0 which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * * http://www.eclipse.org/org/documents/edl-v10.php. */ import javax.swing.JComboBox; import javax.swing.text.JTextComponent; public class Main { public static String value(JTextComponent txt) { return txt.getText(); } public static Object value(JComboBox cb, Object[] val) { int selIndex = cb.getSelectedIndex(); if (selIndex == -1) return null; return val[selIndex]; } }