Well... I of course agree my manual "==" instead of equals() was wrong, but I guess nobody else has ever used EqualsBuilder with Long fields... hard to believe, but hey.
Still, I find EqualsBuilder Javadoc and implementation misleading, http://commons.apache.org/lang/api/org/apache/commons/lang/builder/EqualsBuilder.html#append(java.lang.Object,%20java.lang.Object) says it will use equals() method on objects, but when objects are Long, it does not. Or maybe this is a known pitfall of EqualsBuilder, and I just went in, but this is still very confusing. laurent 2007/12/17, Shawn Garner <[EMAIL PROTECTED]>: > > I know there are tools/plugins to catch it. > Personally I don't make those mistakes (I make different ones) anymore. > > It tends to be those who are new to Java or switch programming languages > frequently. > They are also not likely to use something like Findbugs. > > Nothing beats a compiler warning ;) > > > Thanks, > Shawn D. Garner > > > > Date: Mon, 17 Dec 2007 12:58:22 +0000 > > From: [EMAIL PROTECTED] > > To: [email protected] > > Subject: Re: [lang] equalsBuilder unexplained wrong equality with > > java.lang.Longs ? > > > > On 17/12/2007, Shawn Garner <[EMAIL PROTECTED]> wrote: > > > > > > This is the number one programming error I've seen (not the only one > > > though). > > > > > > Most of the time it is controlling logic that never gets executed. > > > I'm always curious as to why it is never caught and what it will do when > > > fixed. > > > > Try using Findbugs - that will report the error... > > > > > The problem is other programming languages do compare this way. As well > > > as some expression languages. > > > IMO Java should treat "==" as "object.equals" on objects and introduce > > > another operator for object pointer comparison like ".=" > > > > > > I don't think we'll ever see it though because it affects a lot of > > > existing source code making it not backwards compatible. > > > > > > Shawn D. Garner > > > > > > > > > > From: [EMAIL PROTECTED] > > > > To: [email protected]; [EMAIL PROTECTED] > > > > Date: Mon, 17 Dec 2007 04:32:44 -0500 > > > > Subject: RE: [lang] equalsBuilder unexplained wrong equality with > > > > java.lang.Longs ? > > > > > > > > Hello Laurent: > > > > > > > > This behavior is 'normal'. The concepts of object equality (the > > > > equals() method) and object identity (==) are different. The method ' > > > > equals()' defined in Object can be overridden by subclasses and defines > > > > if an object is 'equal' to another. Long overrides the equals method to > > > > check to see if the object passed in wraps the same primitive long > > > > value. OTOH, the == operator compares two object identities, that is, > > > > is the object on the left-hand side the same object as the one on the > > > > right-hand side. Even though two objects instances may be semantically > > > > equal (as in the example below), they are not the same object so fails > > > > the == comparison. > > > > > > > > For example: > > > > > > > > public class TestLongEquals extends TestCase { > > > > > > > > public void testname() throws Exception { > > > > Long long1a = new Long(1); > > > > Long long1b = new Long(1); > > > > Assert.assertFalse(long1a == long1b); > > > > Assert.assertTrue(long1a.equals(long1b)); > > > > } > > > > } > > > > > > > > Gary > > > > Seagull Software > > > > > > > > > -----Original Message----- > > > > > From: Laurent Perez [mailto:[EMAIL PROTECTED] > > > > > Sent: Sunday, December 16, 2007 3:17 PM > > > > > To: Jakarta Commons Users List > > > > > Subject: [lang] equalsBuilder unexplained wrong equality with > > > > > java.lang.Longs ? > > > > > > > > > > Hi ! > > > > > > > > > > I'm struggling with a problem I don't understand, my equalsBuilder's > > > > > isEquals seem to return false when dealing with Longs : > > > > > > > > > > I have a bean class UiTheme, with a property private Long id. > > > > > > > > > > The following equals builder will return false when this.id = 1 and > > > > > rhs.id = 1 : > > > > > > > > > > public boolean equals(Object object) { > > > > > if (!(object instanceof UiTheme)) { > > > > > return false; > > > > > } > > > > > UiTheme rhs = (UiTheme) object; > > > > > return new > > > > > EqualsBuilder().appendSuper(super.equals(object)).append(this.id, > > > > > rhs.id).isEquals(); > > > > > } > > > > > > > > > > If I manually do the equality, as in this.id.equals(rhs.id), then it > > > > > is true (because, well... 1 = 1 !) > > > > > If I do an equality like this.id == rhs.id, then it is false (being a > > > > > Java newbie... maybe it should be false, not sure if doing == instead > > > > > of equals(obj) is correct with Longs) > > > > > > > > > > So I assume (am I wrong ?) that equalsBuilder's isEquals uses "==" > > > > > instead of "equals(obj)"... but I really, really don't understand why. > > > > > > > > > > Can anyone enlighten me ? > > > > > > > > > > thanks ! > > > > > -- > > > > > <a href="http://in-pocket.blogspot.com";>http://in-pocket.blogspot.com > > > > > - Mobile world, technology and more</a> > > > > > > > > > > --------------------------------------------------------------------- > > > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > > --------------------------------------------------------------------- > > > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > _________________________________________________________________ > > > Share life as it happens with the new Windows Live. > > > http://www.windowslive.com/share.html?ocid=TXT_TAGHM_Wave2_sharelife_122007 > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > > > > _________________________________________________________________ > The best games are on Xbox 360. 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