Name: js151677 Date: 06/21/2004


FULL PRODUCT VERSION :
...> java -version
java version "1.5.0-beta3"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-beta3-b55)
Java HotSpot(TM) Server VM (build 1.5.0-beta3-b55, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
...> uname -a
Linux riedquat 2.4.20-64GB-SMP #1 SMP Fri Apr 2 19:10:22 UTC 2004 i686 unknown unknown GNU/Linux


A DESCRIPTION OF THE PROBLEM :
The ReturnType of javax.swing.tree.TreeNode has been changed to use Generics.
But instead of Enumeration<TreeNode> it should be Enumeration<? extends TreeNode>

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Try to compile the source below

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Source compiles
ACTUAL -
Source does not compile because the return type of javax.swing.tree.TreeNode.children() is too specific. It should be Enumeration<? extends TreeNode>, but it is Enumeration<TreeNode> which disables programmers from returning Enumerations that's elements are guaranteed to be of a certain subtype of TreeNode.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.Enumeration;
import javax.swing.tree.TreeNode;

import javax.swing.tree.TreeNode;

public class MyNode implements TreeNode {

    public Enumeration<MyNode> children() {
        return null;
    }
    public boolean getAllowsChildren() {
        return true;
    }
    public MyNode getChildAt(int childIndex) {
        return null;
    }
    public int getChildCount() {
        return 0;
    }
    public int getIndex(TreeNode node) {
        return -1;
    }
    public TreeNode getParent() {
        return null;
    }
    public boolean isLeaf() {
        return true;
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Since the error is in the published sources, it's simple (at least this should be simple for any serious Java developer):
1. Apply the following patch
2. Compile TreeNode.java
3. Put it in a Jar
4. Put that Jar in jre/lib/endorsed

*** TreeNode.java 2004-06-20 21:57:21.000000000 +0200
--- /dist/opt/sun/j2sdk/se/latest/src/javax/swing/tree/TreeNode.java 2004-06-09 09:25:59.000000000 +0200
***************
*** 64,68 ****
      /**
       * Returns the children of the receiver as an <code>Enumeration</code>.
       */
! Enumeration<? extends TreeNode> children();
  }
--- 64,68 ----
      /**
       * Returns the children of the receiver as an <code>Enumeration</code>.
       */
! Enumeration<TreeNode> children();
  }
(Incident Review ID: 280755)
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