Name: gm110360 Date: 05/12/2004


FULL PRODUCT VERSION :
java version "1.4.2_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_04-b05)
Java HotSpot(TM) Client VM (build 1.4.2_04-b05, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
  Program hang when invoke the printStackTrace() of Throwable in the 2nd JVM, which is brought by the code akin to Runtime.getRuntime().exec("java SubApp");

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Make 3 files of the submitted code/script, namely MainApp.java, SubApp.java, launchSubApp.bat.
2. Compile the files
3. java -cp . MainApp
4. Click "Launch SubApp" button.
5. Click "click me" button.


ACTUAL -
  Program hang.

[my comments]
by having examined the log file (log.txt in the same directory), it can be confirmed that the hang is caused by execute the statement: e.printStackTrace(). which may due to consecutive invoking of System.err.println().

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
1. MainApp.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MainApp extends JFrame
{
public MainApp() {
setTitle("MainApp");
JButton button = new JButton("Launch SubApp");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
Runtime.getRuntime().exec("launchSubApp.bat");
} catch (Exception exp) {
exp.printStackTrace();
}
}
});
getContentPane().add(button, BorderLayout.CENTER);
setSize(200, 50);
setVisible(true);
}

public static void main(String[] args) {
new MainApp();
}
}

2. SubApp.java

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class SubApp extends JFrame {
public SubApp() {
setTitle("SubApp");
JButton button = new JButton("Click me");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
throw new Exception("Exception occurs!");
} catch (Exception exp) {
System.out.println("In catach block, before invoke printStackTrace()");
exp.printStackTrace();
// the system will also hang after execute System.err.println() for 9 times
// if replace exp.prinStackTrace() with below statements.
// for (int i = 0; i < 20; i++) {
// System.err.println("i = " + i);
// System.out.println("i = " + i);
// }
System.out.println("Done.");
}
}
});
getContentPane().add(button, BorderLayout.CENTER);
setSize(200,100);
setVisible(true);
}

public static void main(String args[]) {
new SubApp();
}
}

3. launchSubApp.bat

java SubApp > log.txt
---------- END SOURCE ----------
(Incident Review ID: 265056)
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###@###.### 10/5/04 22:31 GMT