使用长时间运行的任务结果重复更新JLabel [英] Update JLabel repeatedly with results of long running task
问题描述
我正在编写一个不断ping服务器的程序。我编写代码来检查一次并将ping放在 JLabel
中并将其放在名为 setPing()
。
I'm writing a program that constantly pings a server. I wrote the code to check it once and put the ping in a JLabel
and put it in a method called setPing()
.
这是我的代码
Here is my code
private void formWindowOpened(java.awt.event.WindowEvent evt) {
setPing();
}
虽然有效但只做了一次,所以我做了:
That worked but only did it once, so I did:
private void formWindowOpened(java.awt.event.WindowEvent evt) {
for(;;){
setPing();
}
}
但这甚至不是第一次起作用。
But this doesn't even work for the first time.
我没有设置setPing方法,因为它太长了所以它是:
I didnt put the setPing method because it was too long so here it is:
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 "";
}
更新
以防万一很重要,我使用netbeans。我创建了一个表单并将此代码放在formWindowOpened evt中,而不是在main中调用它:
UPDATE Just in case this is important, Im using netbeans. I created a form and put this code in the formWindowOpened evt instead of calling it in main:
private void formWindowOpened(java.awt.event.WindowEvent evt) {
ActionListener timerListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
new PingWorker().execute();
}
};
Timer timer = new Timer(1000, timerListener);
timer.start();
jLabel1.setText(label.getText());
timer.stop();
// TODO add your handling code here:
}
class PingWorker extends SwingWorker {
int time;
@Override
protected Object doInBackground() throws Exception {
time = pingTime("lol.garena.com");
return new Integer(time);
}
@Override
protected void done() {
label.setText("" + time);
}
};
public JComponent getUI() {
return label;
}
public static int pingTime(String hostnameOrIP) {
Socket socket = null;
long start = System.currentTimeMillis();
try {
socket = new Socket(hostnameOrIP, 80);
} catch (IOException ex) {
ex.printStackTrace();
} finally {
if (socket != null) {
try {
socket.close();
} catch (IOException e) {
}
}
}
long end = System.currentTimeMillis();
return (int) (end - start);
}
推荐答案
使用Swing 计时器
用于重复任务&一个 SwingWorker
用于长时间运行的任务。例如。以下两者 - 它使用计时器
在 SwingWorker
中重复执行长时间运行任务(ping) 。
Use a Swing Timer
for repeating tasks & a SwingWorker
for long running tasks. E.G. of both below - it uses a Timer
to repeatedly perform a 'long running' task (a ping) in a SwingWorker
.
请参阅 Swing中的并发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。
See Concurrency in Swing for more details on the Event Dispatch Thread and doing long running or repeating tasks in a GUI.
此代码结合了长时间运行的任务('pinging'a服务器)使用 SwingWorker
从重复任务调用(使用基于Swing的<$重复更新 JLabel
) c $ c>计时器。
This code combines a long running task ('pinging' a server) using SwingWorker
invoked from a repeating task (updating the JLabel
repeatedly with the times) using a Swing based Timer
.
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);
}
}
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