[HARMONY-4638] [classlib][luni] ObjectStreamClass.lookup() incorrectly works

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: App-Oriented Bug Reports, Classlib
• Environment: Win XP
• Estimated Complexity: Moderate
• Assignee: Tim Ellison
• Reporter: Mikhail Markov
• Created: 16/Aug/07 08:33
• Updated: 24/Aug/07 10:19
• Resolved: 23/Aug/07 21:30

Description

ObjectStreamClass.lookup() method returns incorrect ObjectStreamClass, which could not be used for replacement in ObjectInputStream.readClassDescriptor(). The test below demonstrates the problem.
Output on RI: Passed
Output on Harmony: FAILED: expected - It's a test, but got - null

--------- Test.java -----------
import java.io.*;

public class Test implements Serializable {
public String str;

public static void main(String[] args) throws Exception {
Test t = new Test();
t.str = "It's a test";
PipedOutputStream pout = new PipedOutputStream();
PipedInputStream pin = new PipedInputStream(pout);
ObjectOutputStream out = new ObjectOutputStream(pout);
TestObjectInputStream in = new TestObjectInputStream(pin);
out.writeObject(t);
Test t1 = (Test) in.readObject();

if (!t.str.equals(t1.str))

{ System.out.println("FAILED: expected - " + t.str + ", but got - " + t1.str); }

else

{ System.out.println("PASSED."); }

}

static class TestObjectInputStream extends ObjectInputStream {
private static ObjectStreamClass testOsc = ObjectStreamClass.lookup(Test.class);

TestObjectInputStream(InputStream in) throws IOException

{ super(in); }

protected ObjectStreamClass readClassDescriptor() throws ClassNotFoundException, IOException {
ObjectStreamClass osc = super.readClassDescriptor();

if(osc.getName().equals("Test"))

{ return testOsc; }

return osc;
}
}
}
-------------------------

I've investigated the problem a bit and found that ObjectStreamClass has package-protected method getLoadFields() which is used by ObjectInputStream to get an array of ObjectStreaFields-s to be loaded from the stream in case of default de-serialization. For ObjectStreamClass created by ObjectStreamClass.lookup() method, this method returns an empty array, thus in case of default de-serialization ObjectInputStream does not try to read any field value from the stream - although there are data to be read in the stream.

I'll provide a patch soon.