Untitled

package ru.whitebox.whiteboxcrm.base;

import java8.util.function.Supplier;

/**
 * Created by Denis Danilchuk on 17.01.18.
 */

public class LazyVal<T> {

    private T field;

    private final Supplier<T> initializer;

    private final T stubVal;

    private final Condition initCondition;

    public LazyVal(Supplier<T> initializer, Condition initCondition, T stubVal) {
        this.initializer = initializer;
        this.initCondition = initCondition;
        this.stubVal = stubVal;
    }

    public LazyVal(Supplier<T> initializer) {
        this(initializer, () -> true, null);
    }

    public T get() {
        if (!initCondition.isSatisfied()) {
            return stubVal;
        }

        if (field == null) {
            field = initializer.get();
        }
        return field;
    }

    public interface Condition {

        boolean isSatisfied();
    }
}