Name: dgC58589 Date: 12/12/97


(from JDK licensee SAS Institute; contact ###@###.###)

When I create subclasses of ObjectOutputStream, calling enableReplaceObject
does not pass String objects and arrays to my replaceObject method.

This is critical in our attempts to provide robust serialization and recovery
of serialized Java Beans in a Java IDE. In order to allow graceful handling of
serial incompatibility, we need to be able to subclass ObjectInputStream
ObjectOutputStream and replace *every* object on output so that we can
partition the stream by object or class. With ObjectOutputStream skipping
replaceObject for Strings and arrays, this is impossible; on reading, we cannot
repair errors such that all backreferences can be resolved.

import java.io.*;
import java.net.*;
import java.util.*;

class MyObjectInputStream extends ObjectInputStream
{
        public MyObjectInputStream(InputStream is) throws IOException
        {
                super(is);
                enableResolveObject(true);
        }

        public Object resolveObject(Object o)
        {
                System.out.println("resolving object from class " + o.getClass().getName());

                return o;
        }
}

public class SerTest
{
        public static void main(String[] argv)
        {
            try {
                String str1 = "Yes Baby !";
                Vector str2 = new Vector(1);
                str2.addElement( str1 );

                ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream("t.tmp"));
                os.writeObject(str1);
                os.writeObject(str2);
                os.close();

                ObjectInputStream is = new MyObjectInputStream(new FileInputStream("t.tmp"));
                System.out.println("1:" + is.readObject());
                System.out.println("2:" + is.readObject());
                is.close();
            }
            catch (Exception ex) {
                ex.printStackTrace();
            }
        }
}

(Review ID: 21822)
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