[cp-patches] Re: Serialization: readResolve and writeReplace in parent class

[Daniel Bonniot]

> This seems like it must be duplicated somewhere, but I couldn't find
> it quickly.

I also looked but could not find code to reuse.

> There is getPackagePortion in Class, maybe making that
> package-private and then using it would be good.

We're in java.io...

I wouldn't mind adding a utility method somewhere if I'm pointed to the right 
place. On irc, Tom seemed to think it's trivial enough to not bother.

> GNU style is to put line breaks before operators, not after them.

OK, fixed, I reattach the patch.

> I wonder if there is a strange case here where someone adds a private
> method to the class hierarchy "later" (after all the other classes are
> compiled).  Should the private method hide the superclass methods of
> the same signature?  Perhaps this is an incompatible change, offhand I
> forget.

I don't know the answer. If somebody can come up with a mauve test...

In the mean time, my patch improves on the current behavior.

Daniel

Index: ChangeLog
===================================================================
RCS file: /cvsroot/classpath/classpath/ChangeLog,v
retrieving revision 1.3915
diff -u -r1.3915 ChangeLog
--- ChangeLog   27 Jun 2005 00:12:08 -0000      1.3915
+++ ChangeLog   27 Jun 2005 17:24:35 -0000
@@ -1,3 +1,8 @@
+2005-06-27  Daniel Bonniot  <address@hidden>
+
+       * java/io/ObjectStreamClass.java
+       (cacheMethods): Fixed lookup of readResolve and writeReplace.
+
 2005-06-27  Tom Tromey  <address@hidden>
 
        * java/lang/Integer.java:
Index: java/io/ObjectStreamClass.java
===================================================================
RCS file: /cvsroot/classpath/classpath/java/io/ObjectStreamClass.java,v
retrieving revision 1.39
diff -u -r1.39 ObjectStreamClass.java
--- java/io/ObjectStreamClass.java      3 Feb 2005 19:20:05 -0000       1.39
+++ java/io/ObjectStreamClass.java      27 Jun 2005 17:24:37 -0000
@@ -486,19 +486,65 @@
     return null;
   }
 
+  private static boolean inSamePackage(Class c1, Class c2)
+  {
+    String name1 = c1.getName();
+    String name2 = c2.getName();
+
+    int id1 = name1.lastIndexOf('.');
+    int id2 = name2.lastIndexOf('.');
+
+    // Handle the default package
+    if (id1 == -1 || id2 == -1)
+      return id1 == id2;
+
+    String package1 = name1.substring(0, id1);
+    String package2 = name2.substring(0, id2);
+
+    return package1.equals(package2);
+  }
+
+  final static Class[] noArgs = new Class[0];
+
+  private static Method findAccessibleMethod(String name, Class from)
+  {
+    for (Class c = from; c != null; c = c.getSuperclass())
+      {
+       try
+         {
+           Method res = c.getDeclaredMethod(name, noArgs);
+           int mods = res.getModifiers();
+
+           if (c != from
+               && (Modifier.isPrivate(mods)
+                   || ! Modifier.isPublic(mods) && ! inSamePackage(c, from)))
+             continue;
+
+           return res;
+         }
+       catch (NoSuchMethodException e)
+         {
+         }
+      }
+
+    return null;
+  }
+
   private void cacheMethods()
   {
     Method[] methods = forClass().getDeclaredMethods();
+
     readObjectMethod = findMethod(methods, "readObject",
                                  new Class[] { ObjectInputStream.class },
                                  Void.TYPE, true);
     writeObjectMethod = findMethod(methods, "writeObject",
                                    new Class[] { ObjectOutputStream.class },
                                    Void.TYPE, true);
-    readResolveMethod = findMethod(methods, "readResolve",
-                                  new Class[0], Object.class, false);
-    writeReplaceMethod = findMethod(methods, "writeReplace",
-                                    new Class[0], Object.class, false);
+
+    // readResolve and writeReplace can be in parent classes, as long as they
+    // are accessible from this class.
+    readResolveMethod = findAccessibleMethod("readResolve", forClass());
+    writeReplaceMethod = findAccessibleMethod("writeReplace", forClass());
   }
 
   private ObjectStreamClass(Class cl)