OPERATING SYSTEM(S):
--------------------
 customer  Windows XP [Version 5.1.2600]

FULL JDK VERSION(S):
--------------------
java version "1.6.0_02"
Java(TM) SE Runtime Environment (build 1.6.0_02-b06)
Java HotSpot(TM) Client VM (build 1.6.0_02-b06, mixed mode)

PROBLEM DESCRIPTION:
--------------------
i) java.io.NotSerializableException for MetalLookAndFeel
ii) MarshallException thrown when a new instace of javax.swing.plaf.metal.MetalLookAndFeel is passed to the server

STEPS TO REPRODUCE:
-------------------
i)  javac SER1.java
ii) java SER1

EXCEPTION/TRACE
----------------
Exception in thread "main" java.io.NotSerializableException: java.lang.Object
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1156)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1509)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1474)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1392)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1150)
        at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
        at SER1.main(SER1.java:7)

TESTCASE DESCRIPTION:
---------------------
import java.io.*;

public class SER1{
   public static void main(String[] args) throws Exception{
	FileOutputStream fos = new FileOutputStream("t.tmp");
        ObjectOutputStream oos = new ObjectOutputStream(fos);
	oos.writeObject(new javax.swing.plaf.metal.MetalLookAndFeel());
	oos.close();
	fos.close();
   }
}

TECHNICAL ANALYSIS
-------------------
The private member variable in BasicLookAndFeel (private Object audioLock) should be made transient to succeed the above test case.
Posted Date : 2007-08-09 15:18:25.0

None

I accepted this bug and verified that the following class
also can't be serialized, so all other Lafs should be checked as well

new BasicLookAndFeel(){
            public String getDescription() {
                return null;
            }

            public String getID() {
                return null;
            }

            public String getName() {
                return null;
            }

            public boolean isNativeLookAndFeel() {
                return false;
            }

            public boolean isSupportedLookAndFeel() {
                return false;
            }
        }
Posted Date : 2007-08-17 09:10:15.0

It isn't a regression. The bug exists in every JDK which I have tested: jdk6, jdk5, jdk1.4.
Posted Date : 2007-08-17 09:31:39.0

The bug cause is very simple. BasicLookAndFeel class, which is the base class of MetalLookAndFeel, contains a field of Object type. The Object class doesn't implement Serializable interface. It is the cause.
A solution is to make the field transient. It is safe because the field is private, non-static and it is used only for synchronization purposes.
Posted Date : 2007-08-17 11:06:02.0