[Java-gnome-developer] boolean equals(...)

[Jonas B. <jb...@ni...>]

Hi!

I found that there are an implementation of equals() in some classes that=
=20
don't take an Object as a parameter, instead they take for example=20
TextIter or such.

It is good practice to always override the equals(Object other) method in=
=20
the Object class instead of creating a parallell equals() method. It can=20
be confusing and error-prone to have several equals() methods.

Further, if one wants to use an object as a key for a HashMap, and one=20
overrides the equals(Object) method, it is also required of the object to=
=20
implement the hashCode() method. Even if the javadoc documentation for=20
Object.hashCode() is maybe a bit cryptic, it gives more information on th=
e=20
subject.

When scanning the java-gnome sources, I found these equals() not taking a=
n=20
Object parameter.

./java/org/gnu/gtk/event/ScaleEvent.java:
        public boolean equals(ScaleEvent event2){
./java/org/gnu/gtk/TextIter.java:
        public boolean equals(TextIter other){
./java/org/gnu/glib/Boxed.java:
        public boolean equals(Boxed other){

There were indeed also classes where both equals(Object) and hashCode()=20
were implemented.

I'll see if I have some time to look into this, maybe I'll post a patch=20
later on if I manage.

- xkr47