Cannot refer to a non-final variable inside an inner class defined in a different method

Question

Edited: I need to change the values of several variables as they run several times thorugh a timer. I need to keep updating the values with every iteration through the timer

Answer 1

I just wrote something to handle something along the authors intention. I found the best thing to do was to let the constructor take all the objects and then in your implemented method use that constructor objects.

However, if you are writing a generic interface class, then you have to pass an Object, or better a list of Objects. This could be done by Object[] or even better, Object ... because it is easier to call.

See my example piece just below.

List lst = new ArrayList();
lst.add("1");
lst.add("2");        

SomeAbstractClass p = new SomeAbstractClass (lst, "another parameter", 20, true) {            

    public void perform( ) {                           
        ArrayList lst = (ArrayList)getArgs()[0];                        
    }

};

public abstract class SomeAbstractClass{    
    private Object[] args;

    public SomeAbstractClass(Object ... args) {
        this.args = args;           
    }      

    public abstract void perform();        

    public Object[] getArgs() {
        return args;
    }

}

Please see this post about Java closures that supports this out of the box: http://mseifed.blogspot.se/2012/09/closure-implementation-for-java-5-6-and.html

Version 1 supports passing of non-final closures with autocasting:
https://github.com/MSeifeddo/Closure-implementation-for-Java-5-6-and-7/blob/master/org/mo/closure/v1/Closure.java

    SortedSet sortedNames = new TreeSet();
    // NOTE! Instead of enforcing final, we pass it through the constructor
    eachLine(randomFile0, new V1(sortedNames) {
        public void call(String line) {
            SortedSet sortedNames = castFirst();  // Read contructor arg zero, and auto cast it
            sortedNames.add(extractName(line));
        }
    });