001    package com.nativelibs4java.util;
002    
003    /**
004     *
005     * @author ochafik
006     */
007    import java.util.Map;
008    
009    public class Pair<U, V> implements Comparable<Pair<U, V>>, Map.Entry<U, V> {
010            private U first;
011            private V second;
012            
013            public Pair(U first, V second) {
014                    this.first = first;
015                    this.second = second;
016            }
017            
018            public Pair() {}
019    
020            public U getFirst() {
021                    return first;
022            }
023            
024            public V getSecond() {
025                    return second;
026            }
027            
028            public void setFirst(U first) {
029                    this.first = first;
030            }
031            
032            public void setSecond(V second) {
033                    this.second = second;
034            }
035            
036            @SuppressWarnings("unchecked")
037            public int compareTo(Pair<U, V> o) {
038                    Comparable<U> cu = (Comparable<U>)getFirst();
039                    if (cu == null) {
040                            if (first != null)
041                                    return 1;
042                    } else {
043                            int d = cu.compareTo(o.getFirst());
044                            if (d != 0)
045                                    return d;
046                    }
047                    
048                    Comparable<V> cv = (Comparable<V>)getSecond();
049                    if (cv == null)
050                            return second != null ? 1 : -1;
051                    return cv.compareTo(o.getSecond());
052            }
053            
054            @Override
055            public String toString() {
056                    return "Pair("+first+", "+second+")";
057            }
058    
059            public U getKey() {
060                    return first;
061            }
062    
063            public V getValue() {
064                    return second;
065            }
066    
067            public V setValue(V value) {
068                    V oldValue = second;
069                    second = value;
070                    return oldValue;
071            }
072    
073            @Override
074            public int hashCode() {
075                    final int prime = 31;
076                    int result = 1;
077                    result = prime * result + ((first == null) ? 0 : first.hashCode());
078                    result = prime * result + ((second == null) ? 0 : second.hashCode());
079                    return result;
080            }
081    
082            @Override
083            public boolean equals(Object obj) {
084                    if (this == obj)
085                            return true;
086                    if (obj == null)
087                            return false;
088                    if (getClass() != obj.getClass())
089                            return false;
090                    final Pair<?, ?> other = (Pair<?, ?>) obj;
091                    if (first == null) {
092                            if (other.first != null)
093                                    return false;
094                    } else if (!first.equals(other.first))
095                            return false;
096                    if (second == null) {
097                            if (other.second != null)
098                                    return false;
099                    } else if (!second.equals(other.second))
100                            return false;
101                    return true;
102            }
103    
104            public boolean isFull() {
105                    return getFirst() != null && getSecond() != null;
106            }
107            
108            public boolean isEmpty() {
109                    return getFirst() == null && getSecond() == null;
110            }
111    }