Ok, now I understand.
Let's take a look at it from Cayenne standpoint. Within a single
DataContext Cayenne has a notion of uniquing, so no two objects are
equal. Across the contexts, objects are equal if their ObjectIds are
equal. Otherwise property value equality means nothing to Cayenne. So
what's equal and what's not is very much context dependent :-) and
therefore java.lang.Object.equals() is the most appropriate default.
Now, IIRC, there won't be much harm done if you decide to implement
those methods on your own. But you don't have to put these methods in
the generated code. A generic method placed in a common superclass
can handle it easily (common superclass, aka "wedge class", is a
subclass of CayenneDataObject and can be set via a "Superclass" field
in the ObjEntity editor panel).
Cayenne persistent objects have access to their ObjectContext, so by
definition they have access to their mapping metadata via
EntityResolver, so comparison can be done in a generic fashion,
iterating via mapped attributes.
Andrus
On Mar 7, 2007, at 6:30 PM, jerome moliere wrote:
2007/3/7, Andrus Adamchik <[EMAIL PROTECTED]>:
Hi Jerome,
Could you give specific examples of the code you want to see
generated?
yes of course I can, this is an excerpt from one of my Java class...
This class has different attributes (name and so on):
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof PersistentField)) {
return false;
}
PersistentField rhs = (PersistentField) obj;
return new EqualsBuilder().append(name, rhs.name).append(
ordinalPosition, rhs.ordinalPosition)
.isEquals();
}// equals()
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return new HashCodeBuilder().append(name).append
(ordinalPosition)
.append(genre).toHashCode();
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return new ToStringBuilder(this).append("column", name).append(
"dataType", dataType).append("isNullable",
isNullable).append("Fk member :",isFkMember).append("isPkmember",
isPkMember())
.append("typname",genre).append("refers to
table:",refersTo)
.toString();
}
these methods use the COmmons Lang main classes (ToStringBuilder
and so on)
to generate the hashcode/equals/toString methods...
From your message I don't quite understand why we need to
change the *default* template?
Because I think it may be generated directly from the Modeler as
the super
classes (generated as _MyClass.java)
Cheers
jerome
--
Jerome Moliere - Mentor/J
http://romjethoughts.blogspot.com/
auteur Eyrolles
