Name: avC70361 Date: 05/14/98



  The java.io.FilePermission is incorrectly deserialized in jdk1.2beta4E when
it has been serialized in jkd1.2-beta3. The InvalidClassException is thrown due
to local class incompatibility.

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

public class FilePermissionTest {

  public static void main(String args[]) {

    FilePermission filePermission;

    String filepath = "FilePermission.ser";

    if (args[0].equals("write")) {

      filePermission = new FilePermission("path", "read");

      ObjectOutputStream stream = null;

      try {

        stream = new ObjectOutputStream(new FileOutputStream(filepath));
        stream.writeObject(filePermission);
        stream.close();

      } catch(IOException e) {
        System.out.println("Couldn't write to " + filepath + " : " + e);
        System.exit(1);
      }

      System.out.println("FilePermission written successfully");

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

      ObjectInputStream stream = null;

      try {

        stream = new ObjectInputStream(new FileInputStream(filepath));
        filePermission = (FilePermission)stream.readObject();

      } catch(InvalidClassException e) {
        System.out.println("Failed:" + e);
        System.exit(1);
      } catch(Exception e) {
        System.out.println(
          "Failed: couldn't read from" + filepath + " : " + e
        );
        System.exit(1);
      }

      System.out.println("Passed");

    }

    System.exit(0);

  }

}
----------------Test output----------

On jdk1.2-beta3:
<avv@stardust(pts/24).263> java -fullversion
java full version "JDK-1.2beta3-N"
<avv@stardust(pts/24).265> java FilePermissionTest write file.ser
FilePermission written successfully
<avv@stardust(pts/24).266> java FilePermissionTest read file.ser
Passed

On jdk1.2-beta4:
<avv@stardust(pts/2).538> java -fullversion
java full version "JDK-1.2beta4-E"
<avv@stardust(pts/2).539> java FilePermissionTest read file.ser
Failed:java.io.InvalidClassException: java.io.FilePermission; Local class not compatible: stream classdesc serialVersionUID=-3107630564271172646 local class serialVersionUID=1578790672454573808

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