Here you can find the source of setSelectedButton(ButtonGroup group, int index)
public static void setSelectedButton(ButtonGroup group, int index)
//package com.java2s; /*/*from w w w . j a v a2 s . c om*/ * Copyright 2000-2013 JetBrains s.r.o. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import javax.swing.*; import java.util.*; public class Main { public static void setSelectedButton(ButtonGroup group, int index) { Enumeration<AbstractButton> enumeration = group.getElements(); int i = 0; while (enumeration.hasMoreElements()) { AbstractButton button = enumeration.nextElement(); group.setSelected(button.getModel(), index == i); i++; } } }