workcraft/workcraft

package org.workcraft.types;

public class Pair<S, T> {
    private final S first;
    private final T second;

    public Pair(S first, T second) {
        this.first = first;
        this.second = second;
    }

    public S getFirst() {
        return first;
    }

    public T getSecond() {
        return second;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((first == null) ? 0 : first.hashCode());
        result = prime * result + ((second == null) ? 0 : second.hashCode());
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        Pair<?, ?> other = (Pair<?, ?>) obj;
        if (first == null) {
            if (other.first != null) {
                return false;
            }
        } else if (!first.equals(other.first)) {
            return false;
        }
        if (second == null) {
            return other.second == null;
        } else {
            return second.equals(other.second);
        }
    }

    public static <T1, T2> Pair<T1, T2> of(T1 o1, T2 o2) {
        return new Pair<>(o1, o2);
    }

    @Override
    public String toString() {
        return "<" + first.toString() + ", " + ((second == null) ? "NULL" : second.toString()) + ">";
    }
}