Double Checked Locking made easy with Java 8 Suppliers

DoubleCheckedSupplier.java

import java.util.function.Supplier;

/**
 * Created by dsmith on 2/16/15.
 *
 * https://en.wikipedia.org/wiki/Double-checked_locking
 *
 */
public class DoubleCheckedSupplier<T> implements Supplier<T> {
    public static <T> Supplier<T> of(Supplier<T> supplier) {
        return new DoubleCheckedSupplier<>(supplier);
    }

    private final Supplier<T> supplier;
    private volatile T t;

    private DoubleCheckedSupplier(Supplier<T> supplier) {
        this.supplier = supplier;
    }

    @Override
    public T get() {
        // use of local variable so we can control number of volatile read / writes
        T local = t; // vol read
        if (local == null) {
            synchronized (supplier) {
                local = t; // vol read
                if (local == null) {
                    local = supplier.get();
                    if (local == null) {
                        throw new IllegalStateException("Supplier should not return a null result");
                    }
                    t = local; // vol write
                }
            }
        }
        return local;
    }
}

StaticSingleton.java

private static final Supplier<MyObject> MYOBJECT = DoubleCheckedSupplier.of(() -> new MyObject());