Try & Option in Java

Option.java

package com.hivefive.ciphernod.scalaz;

import java.util.Collections;
import java.util.Iterator;
import java.util.NoSuchElementException;

import java8.util.function.Function;

/**
 * Created by kinshuk.bairagi on 20/02/16.
 */
public abstract class Option<A> implements Iterable<A> {

    private Option() {
    }


    public abstract A get();

    public abstract A getOrElse(A defaultResult);

    public abstract Iterator<A> iterator();

    public abstract boolean match(Option<A> other);

    @SuppressWarnings("unchecked")
    public static <A> Option<A> Option(final A a) {
        return a == null ? (Option<A>) None : Some(a);
    }

    public static <A> Option<A> Some(final A a) {
        return new _Some<A>(a);
    }

    @SuppressWarnings("unchecked")
    public static <A> Option<A> None() {
        return (Option<A>) None;
    }


    @SuppressWarnings("rawtypes")
    public static final Option None = new _None();

    public abstract void foreach(VoidFunction<A> i);

    public abstract <B> Option<B> map(Function<A,B> i);

    public abstract boolean isDefined();


    private static final class _Some<A> extends Option<A> {
        private final A value;

        private _Some(A a) {
            if (a == null) throw new IllegalArgumentException("argument to Some may not be null");
            this.value = a;
        }

        @Override
        public A get() {
            return this.value;
        }

        @Override
        public A getOrElse(final A ignored) {
            return this.value;
        }

        @Override
        public Iterator<A> iterator() {
            return Collections.<A>singleton(this.value).iterator();
        }

        @Override
        public boolean match(final Option<A> other) {
            return other == None ? false : value.equals(((_Some<A>) other).value);
        }

        @Override
        @SuppressWarnings("unchecked")
        public boolean equals(final Object obj) {
            return obj instanceof Option ? match((Option<A>) obj) : false;
        }

        @Override
        public int hashCode() {
            return this.value.hashCode();
        }

        @Override
        public String toString() {
            return "Some(" + this.value + ")";
        }

        public void foreach(VoidFunction<A> i){
            i.apply(value);
        }

        public <B> Option<B> map(Function<A,B> i){
            return Option.Option(i.apply(value));
        }

        @Override
        public boolean isDefined() {
            return true;
        }

    }


    private static final class _None<A> extends Option<A> {
        private _None() {
        }

        @Override
        public A get() {
            throw new NoSuchElementException("None.get() called");
        }

        @Override
        public A getOrElse(final A result) {
            return result;
        }

        @Override
        public Iterator<A> iterator() {
            return Collections.<A>emptyList().iterator();
        }

        @Override
        @SuppressWarnings("rawtypes")
        public boolean match(final Option other) {
            return other == None;
        }

        @Override
        public boolean equals(final Object obj) {
            return obj == this;
        }

        @Override
        public int hashCode() {
            return 0;
        }

        @Override
        public String toString() {
            return "None";
        }

        public void foreach(VoidFunction i){

        }

        public <B> Option<B> map(Function<A,B> i){
               return Option.None;
        }

        @Override
        public boolean isDefined() {
            return false;
        }
    }

}

Try.java

package com.hivefive.ciphernod.scalaz;

import java.util.Collections;
import java.util.Iterator;

import java8.util.function.Function;

/**
 * Created by kinshuk.bairagi on 20/02/16.
 */
public abstract class Try<A> implements Iterable<A> {

    private Try() {
    }

    public abstract A get() throws Throwable;

    public abstract Iterator<A> iterator();

    public abstract boolean match(Try<A> other);

    public abstract void foreach(VoidFunction<A> i);

    public abstract <B> Try<B> map(Function<A, B> i);

    public abstract boolean isSuccess();

    public static <A> Try<A> Success(final A a) {
        return new Success<A>(a);
    }

    public static <A> Try<A> Failure(Throwable throwable) {
        return new Failure<A>(throwable);
    }

    private static final class Success<A> extends Try<A> {

        private final A value;

        private Success(A a) {
            this.value = a;
        }

        @Override
        public A get() {
            return this.value;
        }

        @Override
        public Iterator<A> iterator() {
            return Collections.<A>singleton(this.value).iterator();
        }

        @Override
        public boolean match(final Try<A> other) {
            return !(other instanceof Failure) && value.equals(((Success<A>) other).value);
        }

        @Override
        @SuppressWarnings("unchecked")
        public boolean equals(final Object obj) {
            return obj instanceof Try && match((Try<A>) obj);
        }

        @Override
        public int hashCode() {
            return this.value.hashCode();
        }

        @Override
        public String toString() {
            return "Some(" + this.value + ")";
        }

        public void foreach(VoidFunction<A> i){
            i.apply(value);
        }

        public <B> Try<B> map(Function<A,B> i){
            return Try.Success(i.apply(value));
        }

        @Override
        public boolean isSuccess() {
            return true;
        }

    }


    private static final class Failure<A> extends Try<A> {

        Throwable error;

        private Failure(Throwable error) {
            this.error = error;
        }

        @Override
        public A get() throws Throwable {
            throw error;
        }

        @Override
        public Iterator<A> iterator() {
            return Collections.<A>emptyList().iterator();
        }


        @Override
        @SuppressWarnings("rawtypes")
        public boolean match(final Try other) {
            return other instanceof Failure;
        }

        @Override
        public boolean equals( Object other) {
             return !(other instanceof Success) && error.equals(((Failure<A>) other).error);
        }

        @Override
        public int hashCode() {
            return error.hashCode();
        }

        @Override
        public String toString() {
            return "None";
        }

        public void foreach(VoidFunction i){
        }

        public <B> Try<B> map(Function<A,B> i){
            return Try.Failure(error);
        }

        @Override
        public boolean isSuccess() {
            return false;
        }


    }

}

VoidFunction.java

package com.hivefive.ciphernod.scalaz;

/**
 * Created by kinshuk.bairagi on 21/02/16.
 */
public interface VoidFunction<T> {
    void apply(T var1);
}