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1437

answers:

14

Is there a better standard way to create getters and setters in Java?

It is quite verbose to have to explicitly define getters and setters for each variable. Is there a better standard annotations approach?

Does Spring have something like this?

Even C# has properties.

+8  A: 

Eclipse has a context menu option that will auto-generate these for you, as I am sure many other IDE's do.

Ascalonian
If you're going to down-vote me, at least provide a reason.
Ascalonian
Not really the best solution, but it's what we're limited to.
Hugo
+3  A: 

Most IDEs provide a shortcut for generating the code (e.g. Eclipse: Right click -> Source -> Generate Getters & Setters), although I realise this is probably not the answer you are looking for.

Some IOC frameworks allow you to annotate properties so that they can be used in the context of the framework e.g. Tapestry IOC, and the latest Spring, I think (but this use is limted to use by the framework)

Joel
+1  A: 

Yeah, you are kind of out of luck. Groovy does generate them for you, but no dice in standard java. If you use Eclipse you can generate them pretty easily, as well as generate hashCode() and equals() functions.

TheBigS
+9  A: 

I'm not sure if you'd consider it 'standard', but Project Lombok addresses this problem. They use annotations to replace much of the verbosity of Java.

Unfortunately, at the moment it works only within Eclipse.

Some people are looking at alternative Java sibling languages, such as Groovy or Scala. I'm afraid it will take some years -if at all- before the JSR figures out a "standardized" way to "fix" this in Java proper.

Carl Smotricz
Tim
+1 to Lombok as very cool, but -1 for being essentially IDE specific. Any other IDE and you get a mass of errors decorating the code as the IDE doeesn't know what's going on. I'm also not entirely sure how it works with debuggers.
Chris Kessel
It works fine with Maven aswell, and they just added a de-lombok option that generates source code without any reference to lombok.
Tim
Currently Lombok definately works in Netbeans, and there have been some reports on JDeveloper as well. The only big one missing is IntelliJ, but now it is open source that might be feasible.
Roel Spilker
+2  A: 

Here is an interesting articles about the subject: http://cafe.elharo.com/java/why-java-doesnt-need-properties-it-already-has-them/

I think properties are a shortcut but it's more a little feature than a real important feature

Jerome C.
I spent a few years developing in Delphi. I always considered properties one of Delphi's finest features. I was always kinda sad that Java doesn't have this feature. Anders Hejlsberg built properties into C# and now the MS folks have them and we don't. It may be a "little" feature but anything that cuts down on code cuts down on errors and increases understandability.
Carl Smotricz
Jerome - I disagree. Binding in Java is currently crippled b/c of lack of support. Imagine if you couldn't obtain the static .class member, but instead had to work with passing strings around. I keep seeing people write that properties in the language would just be syntactic sugar, but that just isn't so.
Kevin Day
+1  A: 

With Netbeans, just start typing get or set where the getter/setter is to be replaced and call up auto complete (Ctrl+Space), it'll give you the option to generate the getter or setter. It'll also give you an option to generate a constructor as well.

monksy
Eclipse has something similar, too.
True Soft
And so does IntelliJ IDEA. That makes 3 major Java IDEs you can use to work around the problem.
Carl Smotricz
+1  A: 

There is no better way that's part of the language -- nothing like a "property" keyword.

One alternative, as other people have mentioned, is to use your IDE to generate them. Another, if you have a lot of objects that need this, is to write your own code generation tool that takes a base class and produces a wrapper with getters and setters.

You could also simply expose the variables as public members. However, down the road this will probably come back to hurt you, when you decide to add validation logic.

However, one final thought: unless your classes are used simply to transfer data, they probably shouldn't expose their internal state. IMO, "behavior" classes with getters and setters are a code smell.

kdgregory
A: 

As a possible alternative, have you tried Scala? It compiles to Java bytecode, and has lots of interesting shortcuts which can make your life as a Java programmer easier.

Properties for instance:

case class Person(var name:String, 
                  var age:Int);
val p = Person("John", 4)
p.name
p.name = "Charlie"
p.name

And the output:

defined class Person
p: Person = Person(John,4)
res7: String = John
res8: String = Charlie
Martin Wickman
Change of technology.
Sylar
Technically Java is a subset of Scala, thus the problem could probably be solved using this approach.
Martin Wickman
I'm with you in liking Scala (and have therefore upvoted you back to 0) but "have you tried Scala?" is asking a bit much. Scala bears a passing resemblance to Java, but the differences are so big that I tried for a while to "code Java in Scala" and gave up. While it's a joy to lose the getters/setters, Scala requires a solid commitment.
Carl Smotricz
A: 

That's the work of the IDE to generate repetitive verbose code as getters/setters

I'm not disagreeing, but I feel it's a sign of a weakness in the language when code generation is required to perform repetitive tasks. If the IDE is smart enough to do it for you, the language should be too!
Carl Smotricz
The IDE is not smart enough to do it, it generates the code if and only if you decide to provide getters and/or setters, and only for the desired instance variables.By default all variable are not readable/modifiable if not declared public.About verbosity, Java provides more than simple read/modif of these variables, but could perform some logic before modifying or returning a value corresponding to variables, again only if you decide to.
At this point you're contradicting your own answer. You're saying it's the work of the user to tell the IDE to generate the repetitive verbose code. Sure, that's exactly how it works, and I feel it's very ugly. Delphi, Ruby and other languages allow you to use simple keywords to auto-generate simple getters and setters while *still* giving you the freedom to add tests, side effects, abstractions or anything else you want, if you want.
Carl Smotricz
It's not that Java's way is terrible, it's just that other languages have nice features for making this stuff easier and pleasant for the programmer, making him more productive.
Carl Smotricz
A: 

Use your IDE to generate it for you and try to minimize the amount of getters/ setters that you have - you will likely enjoy the added benefit of immutability.

I like the C# syntax for properties, I think it's pretty and clean, and pretty clean.

Ravi Wallau
A: 

Well, one option is don't be so afraid of public fields. For simple classes that you know will never do validation or extra work under the hood on get and set, public fields require less boilerplate, are syntactically nicer, and are more efficient.

dsimcha
A: 

I've created some annotations that are not eclipse-specific.

See http://code.google.com/p/javadude/wiki/Annotations

For example:

package sample;

import com.javadude.annotation.Bean;
import com.javadude.annotation.Property;
import com.javadude.annotation.PropertyKind;

@Bean(properties={
    @Property(name="name"),
    @Property(name="phone", bound=true),
    @Property(name="friend", type=Person.class, kind=PropertyKind.LIST)
}) 
public class Person extends PersonGen {
}

My annotations generate a superclass; I think Lombok modifies the actual class being compiled (which is officially not supported by Sun and may break - I could be wrong about how it works, but based on what I've seen they must be doing that)

Enjoy! -- Scott

Scott Stanchfield
A: 

If you use emacs it might be possible to define an emacs macro that does this for you. Any emacs gurus out there? :)

Larry Watanabe
A: 

I agree that getter/setters are verbose. Project Lombok has good answer for it as suggested by others. Otherwise, you could use your IDE's capability to generate them.

fastcodejava