Imported From: https://issues.scala-lang.org/browse/SI-4481?orig=1
Reporter: J Robert Ray (jrray)

@lrytz said:
When you annotate a public field with @BeanProperty, the getter and setter will be public, but the actual field is private. This is what you want.

J Robert Ray (jrray) said:
I understand that the field is private, and that the 'setTest' and 'getTest' generated methods are public. However, the 'test' and 'test_=' methods are also public. Now there are two public ways to assign to test, setTest and test_=.

If I wish to later remove the test field without breaking ABI, I need to create dummy methods for both pairs of methods.
If I wish to later replace the generated setTest with a custom setTest that has a side effect, I must also replace test_= to also perform the side effect.

The compiler allows private vars. Why does the compiler disallow private vars when @BeanProperty is also desired?

@lrytz said:
@BeanProperty is a Java-compatibility tool, it helps you integrating your Scala code with certain Java frameworks. The generated set* and get* methods are just aliases for the Scala getter and setter, and they will have the same visibility.

If you want custom getters or setters, you have to write them manually. It's true that this then does not integrate nicely with @BeanProperty, this problem has been identified before (https://groups.google.com/forum/#!searchin/scala-user/beanproperty/scala-user/CQv2OXttTm8/OvFKJ4-Mf4EJ).

see also #2215.

J Robert Ray (jrray) said:
Thank you for your comments. I feel your scala-user thread reinforces my position. I am not asking to be able to customize the accessors; I was giving examples of why it is important to allow private vars.

My observation in scala 2.8.1 is that the scala accessors take on the visibility of the var, but the Bean accessors are always public.

Using scala -print, if I make my var protected, I see:

    @scala.reflect.BeanProperty private[this] var test: Int = _;
    protected <accessor> def test(): Int = line5$$object$$$$iw$$$$iw.this.test;
    protected <accessor> def test_=(x$$1: Int): Unit = line5$$object$$$$iw$$$$iw.this.test = x$$1;
    def setTest(x$$1: Int): Unit = line5$$object$$$$iw$$$$iw.this.test = x$$1;
    def getTest(): Int = line5$$object$$$$iw$$$$iw.this.test();

getTest and setTest are public (as they should be IMO).

I really just want to know why private is disallowed. I found your comment in the compiler source, "avoids name clashes with private fields in traits." That's unsatisfying. I promise to not name a private field "setTest" in any trait I inherit from!

@lrytz said:
Replying to [comment:4 jrray]:

Thank you for your comments. I feel your scala-user thread reinforces my position. I am not asking to be able to customize the accessors; I was giving examples of why it is important to allow private vars.

My observation in scala 2.8.1 is that the scala accessors take on the visibility of the var, but the Bean accessors are always public.

Yes, the problem with this solution is that it's wrong. When you have two traits with two private variables of the same name, and both have @BeanProperty, and then you mix them into one class, you get a conflict.