我有一个带有JTextArea
组件的GUI应用程序。它用于记录一些信息:
import javax.swing.*;
public class MainWindow {
private JTextArea myTextArea;
public static void main(String[] args) {
new MainWindow();
}
public MainWindow() {
JFrame mainFrame = new JFrame();
myTextArea = new JTextArea();
mainFrame.setBounds(100,100,100,100);
mainFrame.add(myTextArea);
mainFrame.setVisible(true);
for (int i=0; i< 100; i++)
log("Minimal, Complete, Verifable!");
}
private void log(String message) {
myTextArea.append(message);
}
}
它在Windows 7上可以正常工作。但是,在Linux上,几次调用后似乎挂起了整个应用程序。对堆栈的分析表明,GUI线程处于
BLOCKED
状态:"Thread-4" prio=10 tid=0x00007f68e8a63000 nid=0xce7 waiting for monitor entry [0x00007f68f0b40000]
java.lang.Thread.State: BLOCKED (on object monitor)
at java.awt.Component$AccessibleAWTComponent.getLocationOnScreen(Component.java:9445)
- waiting to lock <0x00000007980597e8> (a java.awt.Component$AWTTreeLock)
at javax.swing.JComponent$AccessibleJComponent.getLocationOnScreen(JComponent.java:3670)
at javax.swing.text.JTextComponent$AccessibleJTextComponent.caretUpdate(JTextComponent.java:2608)
at javax.swing.text.JTextComponent.fireCaretUpdate(JTextComponent.java:407)
at javax.swing.text.JTextComponent$MutableCaretEvent.fire(JTextComponent.java:4415)
at javax.swing.text.JTextComponent$MutableCaretEvent.stateChanged(JTextComponent.java:4437)
at javax.swing.text.DefaultCaret.fireStateChanged(DefaultCaret.java:802)
at javax.swing.text.DefaultCaret.changeCaretPosition(DefaultCaret.java:1277)
at javax.swing.text.DefaultCaret.handleSetDot(DefaultCaret.java:1173)
at javax.swing.text.DefaultCaret.setDot(DefaultCaret.java:1154)
at javax.swing.text.DefaultCaret$Handler.insertUpdate(DefaultCaret.java:1726)
at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:202)
at javax.swing.text.AbstractDocument.handleInsertString(AbstractDocument.java:749)
at javax.swing.text.AbstractDocument.insertString(AbstractDocument.java:708)
at javax.swing.text.PlainDocument.insertString(PlainDocument.java:130)
at javax.swing.JTextArea.append(JTextArea.java:477)
是什么原因造成的?
最佳答案
正如@trashgod在注释中所写,GUI对象应仅在事件分发线程上进行操作。如here所述,可以使用SwingUtilities.invokeLater()
实现此目的。
这是log()
方法的固定代码,可以解决此问题:
private void log(final String message) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
infoTextArea.append(LogUtils.formatLogMessage(message));
}
});
}