Java: can I require a child class to define a property value?

I have an abstract base class that many classes extend. I'd like all these classes to define a un开发者_如何学编程ique value for a specific property that is originally defined in the base class (similar to the serialVersionUID property that causes a warning when not defined in classes that inherit from Serializable).

Is there a way for me, within my abstract base class, to declare a property that does not have a value, but requires all extended classes to define a value for it?

Note that the value does not have to be associated with each individual instance, i.e.: it can be defined as static.

Edit: I guess a more basic question I should also ask, since the answers vary so widely, is how does Java implement serialVersionUID (in terms of its signature) such that my IDE raises warnings when it's not defined?

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Fields can not be overridden, but methods can. If you need not enforce that the value is constant, use:

class abstract Super() {
    /**
     * @return the magic value
     */
    abstract MyType getValue();
}

If you do need to enforce that the field is final, you can give each instance its own copy/reference as in the answers of Steve or Mike.

If you can't do that either you can do crazy stuff like:

class Super() {
    private static Map<Class<? extends Super, MyType> map = new ...;

    protected Super(MyType value) {
        if (!map.contains(getClass())) {
            map.put(getClass(), value);
        } else {
            assert map.get(getClass(), value) == value;
        }
    }
}

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Hardly. I'd suggest putting user instructions in your base class' javadoc and checking if property is present before using it: object.class.getDeclaredField("MY_CONSTANT")

I think, Serializable interface is a good example of such approach.

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Something like the following is a typical approach to this:

public abstract class Superclass {

    private final String something;

    public Superclass(String something) {
        this.something = something;
    }

    public String getSomething() {
        return something;
    }
}

public class Subclass {

    public Subclass() {
        super("a value for something");
    }
}

You don't get to have a static property value though.

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Reposting to match the criteria I missed:

public abstract class Abstract {

    private static int field;

    public Abstract(int aValue) {
        field = aValue;
    }

    public int getField() {
        return field;
    }
}

public class Child extends Abstract {

    private static final int value;

    static {
        value = 10; //Pick a value for each class.
    }

    public Child() {
        super(value);
    }
}