RE: [JBoss-user] Primary Key warnings
I changed my hashCode() method as recommended below. I also
made the default constructor change as recommended in the
posts referenced by Alexander (sorry I forgot to check the
archives first).
However, I'm still getting the same warnings.
Any other suggestions?
Thanx.
Norton
-Original Message-
From: danch (Dan Christopherson) [mailto:[EMAIL PROTECTED]]
Sent: Thursday, May 17, 2001 5:14 PM
To: [EMAIL PROTECTED]
Subject: Re: [JBoss-user] Primary Key warnings
/**
* Hash code method.
*/
public int hashCode() {
return(super.hashCode());
}
This is the problem. This is delegating to the Object.hashCode method
that uses the object's address as its input, so when the verifier tries
to verify that your hashCode method is right (by creating two keys and
comparing the hashes) it gets different answers when it should get the
same answer.
maybe
return _guid.toString().hashCode()
?
-danch
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RE: [JBoss-user] Primary Key warnings
Norton,
Your PK equals method:
public boolean equals(Object obj) {
GUID compareTo = (GUID)obj;
if (_guid.toString().equals(compareTo.toString())) {
return(true);
}
return(false);
}
The correct would be:
...
if (_guid.toString().equals(compareTo._guid.toString())) {
...
Correct?
Rafael
On Fri, 18 May 2001, Norton Lam wrote:
I changed my hashCode() method as recommended below. I also
made the default constructor change as recommended in the
posts referenced by Alexander (sorry I forgot to check the
archives first).
However, I'm still getting the same warnings.
Any other suggestions?
Thanx.
Norton
-Original Message-
From: danch (Dan Christopherson) [mailto:[EMAIL PROTECTED]]
Sent: Thursday, May 17, 2001 5:14 PM
To: [EMAIL PROTECTED]
Subject: Re: [JBoss-user] Primary Key warnings
/**
* Hash code method.
*/
public int hashCode() {
return(super.hashCode());
}
This is the problem. This is delegating to the Object.hashCode method
that uses the object's address as its input, so when the verifier tries
to verify that your hashCode method is right (by creating two keys and
comparing the hashes) it gets different answers when it should get the
same answer.
maybe
return _guid.toString().hashCode()
?
-danch
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RE: [JBoss-user] Primary Key warnings
No... The _guid property is private. I've overridden the toString() method to return a _guid.toString(). Ok, but an instance of a class have full access to private fields of another instances of the same class. Norton, could you show us the complete code for GUID class? Bye, Rafael ___ JBoss-user mailing list [EMAIL PROTECTED] http://lists.sourceforge.net/lists/listinfo/jboss-user
RE: [JBoss-user] Primary Key warnings
Ah... I understand now.
The problem is that my GUID class, by definition, creates
a new GUID for every call to the default constructor. I
use it to create unique IDs for newly created EJBs.
Therefore, the below code could never be true. Given
that, I guess I'll just have to live with the warnings.
I'm assuming I'm not violating the EJB spec by designing
my PK class like this, am I? I'll have to check into that.
I was thinking that you guys (the JBoss developers) were
checking for equals() and hashCode() this way due to
the spec, but I guess there's no other way for you to
check for the override of these methods generically.
Thanx to everyone that tried to help.
Norton
P.S. Dain, I'm using BMP for the moment...
-Original Message-
From: Dain Sundstrom
To: '[EMAIL PROTECTED]'
Sent: 5/18/01 1:44 PM
Subject: RE: [JBoss-user] Primary Key warnings
Norton,
I had this same problem. The code you are running into follows:
Object one, two;
try {
one = cls.newInstance();
two = cls.newInstance();
try {
if(!one.equals(two)) {
status = false;
fireSpecViolationEvent(entity, new
Section(9.2.9.b));
}
} catch(NullPointerException e) {} // That's OK - the
implementor
expected the fields to have values
try {
if(one.hashCode() != two.hashCode()) {
status = false;
fireSpecViolationEvent(entity, new
Section(9.2.9.c));
}
} catch(NullPointerException e) {} // That's OK - the
implementor
expected the fields to have values
} catch(IllegalAccessException e) {
// other stuff..
As you see your pk class needs to either throw a NullPointerException or
return a hash codes that are equal. This is kind of lame, so I just
have my
PK just throws a NullPointerException when equals or hashCode is called
on
an uninitialized instance.
By the way, I think the _guid field must be public for CMP to work.
-dain
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[JBoss-user] Primary Key warnings
Hi,
I'm getting warnings from the JBoss verifier that I need to override
equals()
and hashCode() in my primary key class. The problem is, I *am* overriding
these methods.
At the risk of world-wide embarrassment, here's the log and code snippets:
[Verifier]
Bean : Item
Section: 9.2.9
Warning: The primary key class must override equals().
[Verifier]
Bean : Item
Section: 9.2.9
Warning: The primary key class must override hashCode().
/**
* Class that provides a Global Unique ID (GUID)
* for primary keys in the database.
*/
public class GUID implements Serializable {
.
.
.
/**
* Test for equality.
*/
public boolean equals(Object obj) {
GUID compareTo = (GUID)obj;
if (_guid.toString().equals(compareTo.toString())) {
return(true);
}
return(false);
}
/**
* Hash code method.
*/
public int hashCode() {
return(super.hashCode());
}
.
.
.
}
The method signatures are correct, right? What
am I missing?
Thanx.
Norton
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Re: [JBoss-user] Primary Key warnings
/**
* Hash code method.
*/
public int hashCode() {
return(super.hashCode());
}
This is the problem. This is delegating to the Object.hashCode method
that uses the object's address as its input, so when the verifier tries
to verify that your hashCode method is right (by creating two keys and
comparing the hashes) it gets different answers when it should get the
same answer.
maybe
return _guid.toString().hashCode()
?
-danch
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