Checkstyle on class variable

Question

Check style says that for a private class variable "must be declared final".

class Test {
    private int x=1;

    public void set(int x) {
        this.x = x;
    }
}

In the above case it calls to declare x as final however declaring x as final would give error on initializing it in the constructor. What's the catch?

a solution would have been more helpful....and this is just 4 lines of code... — Farrukh Chishti, Mar 05 '13 at 07:41
why are you setting a static variable in an instance method??? — Narendra Pathai, Mar 05 '13 at 07:46
Does the problem still exist? To my knowledge checkstyle shouldn't complain about hte above code. — André Stannek, Jun 21 '13 at 14:33

score 0 · Answer 1 · answered Mar 05 '13 at 07:46

It is a bad style to make private and static field accessible for modifications through setter. You have to do one of the following things:

1) make field x final and remove set method for it.

either

2) make field x non-static (remove static keyword), then it will be not required to make it final.

score 0 · Answer 2 · edited May 23 '17 at 12:03

however declaring x as final would give error on initializing it in the constructor

To initialize static fields use static block.

And, why it should be final ... The reason is that

It is private static and can't be accessed from outside.
If it is not required to be final then no need to make it static

So, either remove static OR use final private static

Now, your other part of code:

public void set(int x) {
    this.x = x;
}

Issues:

static fields should NOT be accessed using this.
Use static block to initialize static fields.

score 0 · Answer 3 · answered Mar 05 '13 at 07:48

0

you cannot change the value of a static final field.

if you really need x to be static, change your method to

public static void setX(int newX){
    [...]

keep in mind, that in static methods "this" cannot be used.

this should solve your problem.

answered Mar 05 '13 at 07:48

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Checkstyle on class variable

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