Java实验报告--计时器（线程）
一、实验目的
了解Java线程的使用方法
二、实验内容
1、使用多线程制作一计时器，要求实现文本框输入一个时间（分），计时结束后提示。
2、系统通过点击按钮可实现启动计时、暂停、结束计时、复位等功能。
三、实验步骤
借助windowBulider制作窗体界面，使用两个Date获取系统时间，通过两次时间相减来计算计时器经过了多长时间。
package test;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Label;
import java.awt.TextField;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Date;
public class thirdapp extends Frame {
private TextField tf = new TextField(30);
private TextField m = new TextField(2);
private TextField s = new TextField(2);
private TextField ms = new TextField(2);
private boolean start = false;
private boolean pause = false;
private int mSecond = 0;
private int second = 0;
private int min = 0;
private int time ;
private float diff = 0; //时间差
private float part = 0; //如要暂停时使用
private Date d1;
private Date d2;
private Button bt_start = new Button("\u5F00\u59CB");
MyThread mt = new MyThread();
thirdapp(){
super("计时器");
setSize(300, 240);
setVisible(true);
setLayout(null);
m.setFont(new Font("Dialog", Font.PLAIN, 35));
m.setBounds(40, 50, 50, 35);
m.setEditable(false);
add(m);
Label label = new Label(":");
label.setAlignment(Label.CENTER);
label.setFont(new Font("Dialog", Font.PLAIN, 35));
label.setBounds(90, 50, 25, 35);
add(label);
s.setFont(new Font("Dialog", Font.PLAIN, 35));
s.setBounds(115, 50, 50, 35);
s.setEditable(false);
add(s);
Label label_1 = new Label(":");
label_1.setAlignment(Label.CENTER);
label_1.setFont(new Font("Dialog", Font.PLAIN, 35));
label_1.setBounds(165, 50, 25, 35);
add(label_1);
ms.setFont(new Font("Dialog", Font.PLAIN, 35));
ms.setBounds(190, 50, 50, 35);
ms.setEditable(false);
add(ms);
bt_start.setBounds(187, 120, 65, 35);
add(bt_start);
bt_start.addActionListener(ActionStart);
tf.setFont(new Font("Dialog", Font.PLAIN, 34));
tf.setBounds(115, 120, 65, 35);
add(tf);
Label label_2 = new Label("\u8BF7\u8F93\u5165\u65F6\u957F");
label_2.setBounds(30, 125, 77, 25);
add(label_2);
Button bt_pause = new Button("\u6682\u505C");
bt_pause.setBounds(15, 180, 60, 35);
add(bt_pause);
bt_pause.addActionListener(ActionPause);
Button bt_reset = new Button("\u590D\u4F4D");
bt_reset.setBounds(147, 180, 60, 35);
add(bt_reset);
bt_reset.addActionListener(ActionReset);
Button bt_stop = new Button("\u7ED3\u675F");
bt_stop.setBounds(212, 180, 60, 35);
add(bt_stop);
bt_stop.addActionListener(ActionStop);
Button bt_continue = new Button("\u7EE7\u7EED");
bt_continue.setBounds(81, 180, 60, 35);
add(bt_continue);
bt_continue.addActionListener(ActionContinue);
addWindowListener(winclose);
mt.start();
}
WindowAdapter winclose = new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
};
ActionListener ActionStart = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO 自动生成的方法存根
start = true;
d1 = new Date();
time = Integer.parseInt(tf.getText());
tf.setEditable(false);
bt_start.setEnabled(false);
}
};
ActionListener ActionPause = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO 自动生成的方法存根
pause = true;
part = diff;
}
};
ActionListener ActionContinue = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO 自动生成的方法存根
d1 = new Date();
pause = false;
}
};
ActionListener ActionStop = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO 自动生成的方法存根
start = false;
bt_start.setEnabled(true);
}
};
ActionListener ActionReset = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO 自动生成的方法存根
start = false;
pause = false;
tf.setText("");
tf.setEditable(true);
m.setText("");
s.setText("");
ms.setText("");
min = 0;
second = 0;
mSecond = 0;
diff = 0;
part = 0;
bt_start.setEnabled(true);
}
};
class MyThread extends Thread{
public void run() {
while(true)
{
validate();
if(start && !pause)
{
d2 = new Date();
diff = d2.getTime() - d1.getTime() + part;
mSecond = (int)diff%1000/10;
second =(int) (diff/1000)%60;
min=(int)diff/1000/60;
m.setText(min+"");
s.setText(second+"");
ms.setText(mSecond+"");
try{
Thread.sleep(5);
}
catch(Exception e){
}
if((second+min*60)==time)
{
pause = true;
Frame fr = new Frame("时间到");
fr.setSize(100,100);
Label finish = new Label("时间到");
fr.add(finish, BorderLayout.CENTER);
fr.addWindowListener(winclose);
fr.setVisible(true);
}
}
}
}
}
public static void main(String[] args) {
thirdapp mt = new thirdapp();
}
}四、实验总结
本次实验使我了解了Java的多线程机制，学会了如何创建并运行一个线程，运用多线程，可以进行一些更复杂的项目了。