Name: sv35042 Date: 10/18/2002


FULL PRODUCT VERSION :
java version "1.3.1_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.1_04-
b02)
Java HotSpot(TM) Client VM (build 1.3.1_04-b02, mixed mode)

FULL OPERATING SYSTEM VERSION :

Windows 2000 SP2

ADDITIONAL
OPERATING SYSTEMS :



EXTRA RELEVANT SYSTEM CONFIGURATION :
Don't think the OS is the problem here.

A DESCRIPTION OF THE PROBLEM :
JTextField.setText() which is JTextComponent's setText() is not
Thread safe contrary to Javadoc of the setText() method.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Please run the source provided below.

EXPECTED VERSUS ACTUAL BEHAVIOR :
Since JavaDoc says this method is ThreadSafe, I expect to see either the
original value or the updated value.

Instead, sometimes you see
"12", "21" or "". Depending on when getText() was executed during
setText().

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.*;
import javax.swing.text.*;

public class SetTextTest {

    
public static void main(java.lang.String[] args) {
    
        /*
         * Uncomment this block to fix
         *
        
final JTextField jtf = new JTextField() {
            public synchronized void setText(String text) {
                
super.setText(text);
            }
            public synchronized String getText() {
                return
super.getText();
            }
        };
        */
        final JTextField jtf = new JTextField();
        
        
jtf.setText("0");
    
        Thread t1 = new Thread() {
            public void run() {
                while (true) {
                    
jtf.setText("1");
                }
            }
        };
        Thread t2 = new Thread() {
            public void run() {
                while (true)
{
                    jtf.setText("2");
                }
            }
        };
        System.out.println("Start");
    
        t1.start();
        
t2.start();
    
        long startTime = System.currentTimeMillis();
    
        long runFor = 30000;
    
        
while (System.currentTimeMillis() < startTime + runFor) {
            
SwingUtilities.invokeLater(new Runnable() {
                public void run() {
    
                    String currentText =
jtf.getText();
    
                    if (currentText.length() != 1) {
                        System.out.println("Text: '" +
currentText + "'");
                    }
                }
            });
    
        }
        System.out.println("Finished");
        
System.exit(0);
    }
}
---------- END SOURCE ----------

CUSTOMER WORKAROUND :
Making get and set synchronized will solve it.

But given that Swing is
mostly not Thread Safe, I guess you won't change this. But please in
JavaDoc that setText() is not Thread Safe in this sense. May be it is from a
data integrety point of view.


        final JTextField jtf = new
JTextField() {
            public synchronized void setText(String text) {
                
super.setText(text);
            }
            public synchronized String getText() {
                
return super.getText();
            }
        };
(Review ID: 159960)
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