Java 使用长时间运行任务的结果重复更新JLabel
我正在编写一个程序,不断ping服务器。我编写了代码来检查它一次,并将ping放在Java 使用长时间运行任务的结果重复更新JLabel,java,swing,jlabel,ping,event-dispatch-thread,Java,Swing,Jlabel,Ping,Event Dispatch Thread,我正在编写一个程序,不断ping服务器。我编写了代码来检查它一次,并将ping放在JLabel中,然后将其放在名为setPing()的方法中 这是我的密码 这很有效,但只做了一次,所以我做了: private void formWindowOpened(java.awt.event.WindowEvent evt) { for(;;){ setPing(); } } 但这甚至不是第一次起
JLabel
中,然后将其放在名为setPing()的方法中
这是我的密码
这很有效,但只做了一次,所以我做了:
private void formWindowOpened(java.awt.event.WindowEvent evt) {
for(;;){
setPing();
}
}
但这甚至不是第一次起作用
我没有使用设置方法,因为它太长,所以它是:
public String setPing(){
Runtime runtime = Runtime.getRuntime();
try{
Process process = runtime.exec("ping lol.garena.com");
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
while ((line = br.readLine()) != null) {
int i = 0;
i = line.indexOf("Average");
if(i > 0){
String finalPing = "";
line.toCharArray();
try
{
finalPing = "";
for(int x = i; x < i + 17; x++)
{
finalPing = finalPing + (line.charAt(x));
}
}catch(IndexOutOfBoundsException e)
{
try
{
finalPing = "";
for(int x = i; x < i + 16; x++)
{
finalPing = finalPing + (line.charAt(x));
}
}catch(IndexOutOfBoundsException f)
{
try
{
finalPing = "";
for(int x = i; x < i + 15; x++)
{
finalPing = finalPing + (line.charAt(x));
}
}catch(IndexOutOfBoundsException g){}
}
}
String final1Ping = finalPing.replaceAll("[^0-9]", "");
return final1Ping;
}
}
}catch(IOException e){
}
return "";
}
你可以用一个小盒子。问题是您正在阻塞主线程,从而阻塞了程序。要解决此问题,请启动后台线程
,以重复更新组件
(注意:您需要在上更新GUI组件,因此请使用)
使用Swing计时器执行重复任务,使用SwingWorker
执行长时间运行的任务。例如,在以下两种情况下-它使用计时器
在SwingWorker
中重复执行“长时间运行”任务(ping)
import java.awt.event.*;
import javax.swing.*;
import java.net.Socket;
public class LabelUpdateUsingTimer {
static String hostnameOrIP = "stackoverflow.com";
int delay = 5000;
JLabel label = new JLabel("0000");
LabelUpdateUsingTimer() {
label.setFont(label.getFont().deriveFont(120f));
ActionListener timerListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new PingWorker().execute();
}
};
Timer timer = new Timer(delay, timerListener);
timer.start();
JOptionPane.showMessageDialog(
null, label, hostnameOrIP, JOptionPane.INFORMATION_MESSAGE);
timer.stop();
}
class PingWorker extends SwingWorker {
int time;
@Override
protected Object doInBackground() throws Exception {
time = pingTime();
return new Integer(time);
}
@Override
protected void done() {
label.setText("" + time);
}
};
public static int pingTime() {
Socket socket = null;
long start = System.currentTimeMillis();
try {
socket = new Socket(hostnameOrIP, 80);
} catch (Exception weTried) {
} finally {
if (socket != null) {
try {
socket.close();
} catch (Exception weTried) {}
}
}
long end = System.currentTimeMillis();
return (int) (end - start);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
new LabelUpdateUsingTimer();
}
};
SwingUtilities.invokeLater(r);
}
}
有关事件调度线程以及在GUI中执行长时间运行或重复任务的更多详细信息,请参阅
此代码使用从重复任务调用的SwingWorker
(使用基于Swing的计时器重复更新JLabel
)组合长时间运行的任务(“ping”服务器)
import java.awt.event.*;
import javax.swing.*;
import java.net.Socket;
public class LabelUpdateUsingTimer {
static String hostnameOrIP = "stackoverflow.com";
int delay = 5000;
JLabel label = new JLabel("0000");
LabelUpdateUsingTimer() {
label.setFont(label.getFont().deriveFont(120f));
ActionListener timerListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new PingWorker().execute();
}
};
Timer timer = new Timer(delay, timerListener);
timer.start();
JOptionPane.showMessageDialog(
null, label, hostnameOrIP, JOptionPane.INFORMATION_MESSAGE);
timer.stop();
}
class PingWorker extends SwingWorker {
int time;
@Override
protected Object doInBackground() throws Exception {
time = pingTime();
return new Integer(time);
}
@Override
protected void done() {
label.setText("" + time);
}
};
public static int pingTime() {
Socket socket = null;
long start = System.currentTimeMillis();
try {
socket = new Socket(hostnameOrIP, 80);
} catch (Exception weTried) {
} finally {
if (socket != null) {
try {
socket.close();
} catch (Exception weTried) {}
}
}
long end = System.currentTimeMillis();
return (int) (end - start);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
new LabelUpdateUsingTimer();
}
};
SwingUtilities.invokeLater(r);
}
}
我太懒了。正在等待有人发布此消息:-@peeskillet需要一定数量的错误或过于复杂的答案才能达到我的“我只想‘坐在这里看着集群’的极限。”我不明白。你能告诉我如何和在哪里调用我的方法setPing()吗?是的,我确实替换了label.setText(“+rand.nextInt(1000))代码>使用setPing()
但是这是一个非静态的方法,因为它更新了jLableloh,等等,我发现了!谢谢!好的,我做了这个,它有点效果。我将设置方法从public void
更改为public String
,现在不再更改jLabel的文本,而是将ping作为字符串返回。现在,当我在代码中替换refToJLabel.setText(Math.random())使用System.out.println(setPing())进行编码>操作代码>,在控制台中连续打印ping。但是当我放置jLabel1.setText(setPing())时代码>它什么也不做。在这种情况下“工作”意味着“失败”。它应该完美地工作。我注意到这段代码没有延迟线程
循环,所以我猜对标签的大多数更新都会被忽略。
(new Thread((new Runnable(){
@Override
public void run(){
while(true){
SwingUtilities.invokeLater(new Runnable(){
@Override
public void run(){
refToJLabel.setText(Math.random());
}
});
}
}
}))).start();
import java.awt.event.*;
import javax.swing.*;
import java.net.Socket;
public class LabelUpdateUsingTimer {
static String hostnameOrIP = "stackoverflow.com";
int delay = 5000;
JLabel label = new JLabel("0000");
LabelUpdateUsingTimer() {
label.setFont(label.getFont().deriveFont(120f));
ActionListener timerListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new PingWorker().execute();
}
};
Timer timer = new Timer(delay, timerListener);
timer.start();
JOptionPane.showMessageDialog(
null, label, hostnameOrIP, JOptionPane.INFORMATION_MESSAGE);
timer.stop();
}
class PingWorker extends SwingWorker {
int time;
@Override
protected Object doInBackground() throws Exception {
time = pingTime();
return new Integer(time);
}
@Override
protected void done() {
label.setText("" + time);
}
};
public static int pingTime() {
Socket socket = null;
long start = System.currentTimeMillis();
try {
socket = new Socket(hostnameOrIP, 80);
} catch (Exception weTried) {
} finally {
if (socket != null) {
try {
socket.close();
} catch (Exception weTried) {}
}
}
long end = System.currentTimeMillis();
return (int) (end - start);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
new LabelUpdateUsingTimer();
}
};
SwingUtilities.invokeLater(r);
}
}