Is there an equivalent of '==' from Java in EE 6 JSF EL

Question

I am working in JSF 2 with Primefaces 3.4 and I found an example where '==' in my xhtml does not behave like '==' in Java. I could not find details for '==' operator in Java EE 6 documentation. What does it exactly do? Is there an equivalent of Java '==' for Objects in EL?

@LuiggiMendoza: Yes, it is what? There were two options given. — recursive, Oct 21 '13 at 15:42
From EL, using `==` is **the same of** using `==` for primitives and `equals` for objects, like `String`s. Did you at least tried it? — Luiggi Mendoza, Oct 21 '13 at 15:43
Also, this is EL, it is not just for Java EE nor JSF, it also works in EL `${}` used in a servlet container like Tomcat. — Luiggi Mendoza, Oct 21 '13 at 15:44
@Luiggi Is there an equivalent to `==` for object references in EL? — Sotirios Delimanolis, Oct 21 '13 at 15:44
Sotirios- this is exactly what I was after Thank you Luiggi for extra clarifications. — bjedrzejewski, Oct 21 '13 at 15:45
@SotiriosDelimanolis AFAIK no, and if your class doesn't implement `equals` it will use default `Object#equals` that ends using `==`. — Luiggi Mendoza, Oct 21 '13 at 15:46
http://www.roseindia.net/java/javaee6/ExpressionLanguage.shtml — PM 77-1, Oct 21 '13 at 15:46
@PM77-1 IMO roseindia.net teaches JSF and related technologies in the wrong way. If you want to refer to a good resource about EL, use [StackOverflow EL's wiki](http://stackoverflow.com/tags/el/info) instead. — Luiggi Mendoza, Oct 21 '13 at 15:48
@user2511414 AFAIK `is` is not an EL keyword nor a valid operator. Refer to [EL Operators](http://docs.oracle.com/javaee/7/tutorial/doc/jsf-el006.htm#BNAIK). — Luiggi Mendoza, Oct 21 '13 at 15:52
@LuiggiMendoza Oh sorry, I just got it wrong with another tag libraries, sorry, thanks for notify, good catch :) — , Oct 21 '13 at 16:04
This is an [XY problem](http://meta.stackexchange.com/q/66377/166890). "'==' in my xhtml does not behave like '==' in Java" isn't true unless your expectations are incorrect. I suggest you solve *that* problem. — user207421, Oct 22 '13 at 00:45

Luiggi Mendoza · Accepted Answer · 2015-05-14T14:37:54.973

2

Is there an equivalent of Java '==' for Objects in EL?

Looks like it is not, but you don't really need it. EL == (and eq) will use the equals method when comparing object references, and it already supports null comparison. If your class happens to not override equals, then it will use Object#equals that ends using Java == for equality check.

If your class happens to override equals method, make sure to write a good implementation. As example:

public boolean equals(Object o) {
    if (o == null) {
        return false;
    }
    if (this == o) {
        return true;
    }
    if (...) {
        //add here the rest of the equals implementation...
    }
    return false;
}

More info:

Java EE tutorial: Expression Language: Operators

edited May 14 '15 at 14:37

answered Oct 21 '13 at 15:55

Luiggi Mendoza

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I know I can use equals, but my question is to bypass it and use '==' instead. If this is not possible, then I will wait a bit more (in case someone has a genius answer) and accept your answer. – bjedrzejewski Oct 21 '13 at 16:01
@jedrus07 maybe if your post your actual problem you could get a more accurate answer. – Luiggi Mendoza Oct 21 '13 at 16:05
@LuiggiMendoza Mendoza The **link** *Java EE tutorial: Expression Language: Operators* is **broken**. Please update it. – OO7 May 14 '15 at 13:25
@OO7 link updated. Thanks. I recommend you to update links whenever you can, not only here but in other Q/As as well. – Luiggi Mendoza May 14 '15 at 14:38
@Luiggi Mendoza Ok I'll. – OO7 May 15 '15 at 05:00

Is there an equivalent of '==' from Java in EE 6 JSF EL

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