我有一个标签，不会在GUI的同一个实例中更新。 如果我单击应该更新jLabel（＆＃34; testLabel＆＃34;来自代码块）的值的jButton，我必须再次运行java程序以查看更改。如何让它出现在同一个实例中的按钮单击上？ 我知道invokelater，我一直在玩它试图让它实时更新，但没有运气。我现在已经坚持了一段时间，所以任何帮助都会受到赞赏。 使用下面列出的代码块，我仍然需要运行GUI的新实例来获取要更新的值。
相关代码：
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MISControlPanel window = new MISControlPanel();
window.frame.setVisible(true);
// testLabel.setText(CN);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
JButton searchComputerButton = new JButton("Search");
searchComputerButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String line;
BufferedWriter bw = null;
BufferedWriter writer = null;
try {
writer = new BufferedWriter(new FileWriter(tempFile));
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
// String lineToRemove = "OU=Workstations";
String s = null;
Process p = null;
/*
* try { // p = Runtime.getRuntime().exec(
* "cmd /c start c:\\computerQuery.bat computerName"); } catch
* (IOException e1) { // TODO Auto-generated catch block
* e1.printStackTrace(); }
*/
try {
p = Runtime.getRuntime().exec("c:\\computerQuery.bat");
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
StringBuffer sbuffer = new StringBuffer();
BufferedReader in = new BufferedReader(new InputStreamReader(p
.getInputStream()));
try {
while ((line = in.readLine()) != null) {
System.out.println(line);
// textArea.append(line);
String dn = "CN=FDCD111304,OU=Workstations,OU=SIM,OU=Accounts,DC=FL,DC=NET";
LdapName ldapName = new LdapName(dn);
String commonName = (String) ldapName.getRdn(
ldapName.size() - 1).getValue();
}
ComputerQuery.sendParam();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (InvalidNameException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} finally
{
try {
fw.close();
}
catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
try {
in.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
ComputerQuery.sendParam();
}
});
try (BufferedReader br = new BufferedReader(new FileReader(
"resultofbatch.txt"))) {
final Pattern PATTERN = Pattern.compile("CN=([^,]+).*");
try {
while ((sCurrentLine = br.readLine()) != null) {
String[] tokens = PATTERN.split(","); // This will return
// you a array,
// containing the
// string array
// splitted by what
// you write inside
// it.
// should be in your case the split, since they are
// seperated by ","
// System.out.println(sCurrentLine);
CN = sCurrentLine.split("CN=", -1)[1].split(",", -1)[0];
System.out.println(CN);
testLabel.setText(CN);
}
完整的班级代码 http://pastebin.com/havyqMxP
计算机查询类（小班） http://pastebin.com/Q89BCjya
答案 0 :(得分：2)
正如所承诺的......这是一个使用swing worker获取URL内容的简单示例，用于将获取内容（长时间运行的任务）的任务与更新swing组件的任务分离。这将显示您应如何处理此问题的示例......
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URL;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingWorker;
/* FrameDemo.java requires no other files. */
public class MainWindow extends JFrame {
private static final Logger LOOGER = Logger.getLogger(MainWindow.class.getName());
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private JLabel statusLabel = new JLabel("Status");
private JButton actionButton = new JButton("Push me");
public MainWindow() {
super("FrameDemo");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
statusLabel = new JLabel("Status");
actionButton = new JButton("Push me");
statusLabel.setPreferredSize(new Dimension(400, 50));
actionButton.setPreferredSize(new Dimension(100, 50));
getContentPane().setLayout(new BorderLayout());
getContentPane().add(statusLabel, BorderLayout.NORTH);
getContentPane().add(actionButton, BorderLayout.CENTER);
actionButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// THIS METHOD IS INVOKED WITHIN THE EVENT DISPATCH THREAD!!.. SO IS CRUCIAL TO NOT PERFORM
// HERE LONG TIME RUNNING TASKS...
actionButton.setEnabled(false); // let's disable this button, in order to avoid invoking
// multiple times the same task and messing up the entire app...
UrlFechterSwingWorker urlFechterSwingWorker = new UrlFechterSwingWorker();
urlFechterSwingWorker.execute();
}
});
}
public void display() {
pack();
setVisible(true);
}
private class UrlFechterSwingWorker extends SwingWorker<String, String> {
@Override
public String doInBackground() { // this method is executed under a worker thread
BufferedReader in;
StringBuilder sb = new StringBuilder();
try {
URL url = new URL("http://www.stackoverflow.com");
in = new BufferedReader(new InputStreamReader(url.openStream()));
String line = in.readLine();
while (line != null) {
sb.append(line);
publish(line); // publish partial results....
line = in.readLine();
}
in.close();
} catch (Exception e) {
LOOGER.log(Level.SEVERE, "", e);
}
return sb.toString();
}
@Override
protected void process(List<String> readedLines) { // this method in the Event dispatch Thread
// do what you want to do with the readedLines....
statusLabel.setText("The doInBackground read... " + readedLines.size() + " lines");
}
@Override
public void done() { // this method in the Event dispatch Thread
// do what you want when the process finish
actionButton.setEnabled(true); // well.. at least i would like to enable the button again...
}
}
public static void main(String[] args) {
MainWindow mainWindow = new MainWindow();
mainWindow.display();
}
}
以下是更多提示：
在您（或多或少）了解上述示例中的工作原理之后......您必须实现一个执行所有LDAP内容的正确doInBackground方法，为此您必须让你的思想构思一种向最终用户通报进展的方式......我的意思是，看看我的例子，对于进步的进展是非常糟糕的...我所说的所有事情都是，我们读到了“一些行“来自给定的网址。您应该考虑什么是告知有关您的任务进度的最佳方式..除了对基础域模型的理解之外，没有此模板。
请记住，摇摆工人有两种方式来告知进展情况。
publish和process方法。 （如上例所示）doInBackground内的内部属性（进度和状态），并将PropertyChangeListener附加到swing工作者。这个propertyChangeListener对象有一个签名为public void propertyChange(PropertyChangeEvent evt)的方法（在我的观点上稍微复杂一些......）耐心和好运！