Name: avC70361 Date: 12/11/97
  The java.util.HashMap fails to be deserialized on Windows or Solaris platform
if the platform differs from one the class has been serialized on due to the
incompatibility of the local classes on these platforms.

Here is the test demonstrating the bug.
---------------HashMapTest.java------------
import java.util.*;
import java.io.*;

public class HashMapTest {

  public static void main(String args[]) {

    if (args[0].equals("write")) {

      try {

        FileOutputStream fos = new FileOutputStream(args[1]);
        ObjectOutputStream ostream = new ObjectOutputStream(fos);

        ostream.writeObject(new HashMap());
        ostream.flush();
        fos.close();

        System.out.println(args[1] + " is successfuly created");

      } catch(IOException e) {
        System.out.println("Unexpected exception : " + e);
      }

    } else if (args[0].equals("read")) {

      try {

        FileInputStream fis = new FileInputStream(args[1]);
        ObjectInputStream istream = new ObjectInputStream(fis);

        HashMap map = (HashMap)istream.readObject();

        System.out.println(args[1] + " is successfuly read");

      } catch(Exception e) {
        System.out.println("Unexpected exception : " + e);
      }

    }

  }

}
------------The test output-------
on Windows NT:

>java HashMapTest write HashMap.ser
HashMap.ser is successfuly created
>java HashMapTest read HashMap.ser
HashMap.ser is successfuly read

on Solaris:
#>java HashMapTest read HashMap.ser
Unexpected exception : java.io.InvalidClassException: java.util.HashMap; Local class not compatible

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