java一个简单的点名程序源码

package com.file; import java.awt.BorderLayout; import java.awt.event.*; import javax.swing.*; public class Dian1 implements Runnable{ JFrame jf = new JFrame("==="); JButton start1=new JButton("开始"); JButton stop1=new JButton("停止"); JPanel jp1=new JPanel(); JPanel jp2=new JPanel(); JLabel jl=new JLabel("欢迎到来第一次动画点名",JLabel.CENTER);//设置jl居中 String[] students = { "东方 ", "乾坤", "俊", "小飞", "程", "梦梦", "军伟", "微", "雄", "晨旭", "哲", "贻伟", "晓帆", "朗", "岳民", "佳", "捧", "智成", "清福", "宗博", "郭 毅", "航", "亚飞", "凯", "博义", "瑜", "锐", " 海峰", "勇", "山", "小文", "猛", "红科" }; //使用Random随机出数 public int getStudentIndex(){ int totalStudentNum = students.length; int selectIndex = (int)(Math.random()*totalStudentNum); return selectIndex; } Boolean go=true; Thread rollThread =null; public Dian1(){ jf.setLayout(new BorderLayout()); jf.setVisible(true); jf.setSize(240,300); jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); jf.add(jp2,BorderLayout.SOUTH); jp2.add(start1); jp2.add(stop1); jf.add(jl); start1.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e) { String string =e.getActionCommand(); if(string.equals("开始")){ start(); } } }); stop1.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent e) { String string =e.getActionCommand(); if(string.equals("停止")){ go=!go; } } }); } public void start(){ if(null == rollThread){ rollThread = new Thread(this); rollThread.start(); } } public void run() { while(true) { if(go){ int stuNum = getStudentIndex(); jl.setText(students[stuNum]+ ""); } try { Thread.sleep(20); }catch(Exception e){} } } public static void main(String[] args) { new Dian1(); } }