<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>org.swing</groupId><artifactId>swing</artifactId><version>0.0.1-SNAPSHOT</version><packaging>jar</packaging><name>swing</name><url>http://maven.apache.org</url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>3.8.1</version><scope>test</scope></dependency></dependencies>
</project>

package org.swing.jradiobutton;import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;import javax.swing.BorderFactory;
import javax.swing.ButtonGroup;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JRadioButton;public class JRadioButtonTest {JFrame f = null;public JRadioButtonTest() {f = new JFrame("单选框示例");// 创建一个JFrame窗口对象Container contentPane = f.getContentPane();// 创建一个内容面板容器contentPane.setLayout(new FlowLayout());// 设置该窗口的布局JPanel p1 = new JPanel();// 创建一个面板对象p1.setLayout(new GridLayout(1, 3));// 设置布局管理器的格式p1.setBorder(BorderFactory.createTitledBorder("选择你喜欢的城市"));// 定义3个JRadioButton单选按钮JRadioButton r1 = new JRadioButton("北京");JRadioButton r2 = new JRadioButton("上海");JRadioButton r3 = new JRadioButton("广州");// 创建一个按钮组对象，将按钮绑定成一组，实现只能选中一个ButtonGroup group = new ButtonGroup();group.add(r1);group.add(r2);group.add(r3);// 将按钮对象添加到面板中p1.add(r1);p1.add(r2);p1.add(r3);r1.setSelected(true);// 设置r1单选按钮的状态为选中// 将面板对象添加到内容面板容器中contentPane.add(p1);f.pack();// 自动调节窗口大小f.setVisible(true);// 显示窗口f.addWindowListener(new WindowAdapter() {// 添加一个窗口监听器@Overridepublic void windowClosing(WindowEvent e) {System.exit(0);}});}public static void main(String[] args) {new JRadioButtonTest();}}