Java 计时器获取实时毫秒
我的程序有问题。我想在1秒内得到一个等于1000的实时毫秒。这是我的密码:Java 计时器获取实时毫秒,java,swing,javax.swing.timer,Java,Swing,Javax.swing.timer,我的程序有问题。我想在1秒内得到一个等于1000的实时毫秒。这是我的密码: import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.Timer; class lsen implements ActionListener{ int ms = 0; int s = 0; int m = 0; public void actionPerf
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;
class lsen implements ActionListener{
int ms = 0;
int s = 0;
int m = 0;
public void actionPerformed(ActionEvent e){
this.ms++;
if(this.ms == 500){
this.s++;
this.ms = 0;
}
if(this.s == 60){
this.m++;
this.s = 0;
}
}
public int getMS(){
return this.ms;
}
public int getSS(){
return this.s;
}
public int getMM(){
return this.m;
}
}
public class stopwatch_main{
public static void main(String[] args) {
lsen l = new lsen();
Timer t = new Timer(0,l);
t. start();
while(true){
System.out.println(l.getMM()+":"+l.getSS()+":"+l.getMS());
}
}
}
除了声明一个整数并递增外,还有其他方法获得毫秒吗
while(true)
,取而代之的是使用Swing计时器,因为这就是计时器的用途——在Swing GUI中重复调用,而不必求助于线程中断while(true)
构造import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Timer;
class Lsen implements ActionListener {
public static final int MSECS_PER_SEC = 1000;
public static final int SECS_PER_MIN = 60;
public static final int MIN_PER_HR = 60;
private static final String TIME_FORMAT = "%02d:%02d:%02d:%03d";
private long startTime;
private JTextField timeField;
public Lsen(JTextField timeField) {
this.timeField = timeField;
}
public void actionPerformed(ActionEvent e) {
if (startTime == 0L) {
startTime = System.currentTimeMillis();
} else {
long currentTime = System.currentTimeMillis();
int diffTime = (int) (currentTime - startTime);
int mSecs = diffTime % MSECS_PER_SEC;
diffTime /= MSECS_PER_SEC;
int sec = diffTime % SECS_PER_MIN;
diffTime /= SECS_PER_MIN;
int min = diffTime % MIN_PER_HR;
diffTime /= MIN_PER_HR;
int hours = diffTime;
String time = String.format(TIME_FORMAT, hours, min, sec, mSecs);
// System.out.println("Time: " + time);
timeField.setText(time);
}
}
}
public class StopWatchMain {
private static final int TIMER_DELAY = 15;
public static void main(String[] args) {
final JTextField timeField = new JTextField(10);
timeField.setEditable(false);
timeField.setFocusable(false);
JPanel panel = new JPanel();
panel.add(new JLabel("Elapsed Time:"));
panel.add(timeField);
Lsen l = new Lsen(timeField);
Timer t = new Timer(TIMER_DELAY, l);
t.start();
JOptionPane.showMessageDialog(null, panel);
t.stop();
}
}
编辑
您询问长数据类型的含义。请看这里:。您将看到long表示长整数,因此您可以将其视为类似于int,但能够容忍更大的正负值而不会溢出。如果我理解正确,您的意图是让
actionPerformed
方法每秒调用1000次,即恰好每毫秒调用一次。这几乎是不可能的。您可能会用自己的线程来接近它,并忙于等待,但即使这样,它也会很难。(“Busy waiting”在这里确实指的是一个不受限制的while(true)
循环-这是Java中最接近“实时”的循环,但您几乎不必这样做……)谢谢!这非常有用,我稍后将分析代码:)difftime有什么用?我无法理解长时间的计算。我可以要求任何关于长数据类型的参考吗?这对我来说很新鲜me@AdrianManuelCleofe:请参阅编辑以回答及其包含的链接。