org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/util/Pair.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Philippe Sawicki (INF4990.A2010@gmail.com)   - Initial API and implementation
  11  *   Mathieu Denis    (mathieu.denis55@gmail.com) - Refactored code
  12  *   Bernd Hufmann - Integrated to TMF, fixed hashCode() and equals() methods
  13  *******************************************************************************/
  14 package org.eclipse.linuxtools.tmf.core.util;
  15
  16 /**
  17  * Pair utility class, encapsulates a pair of objects.
  18  *
  19  * @param <A>
  20  *            The type of the first object.
  21  * @param <B>
  22  *            The type of the second object.
  23  *
  24  * @author Philippe Sawicki
  25  * @since 2.0
  26  */
  27 public class Pair<A, B> {
  28
  29     /**
  30      * A reference to the first object.
  31      */
  32     protected A fFirst;
  33     /**
  34      * A reference to the second object.
  35      */
  36     protected B fSecond;
  37
  38     /**
  39      * Constructor.
  40      * @param first
  41      *            The pair's first object.
  42      * @param second
  43      *            The pair's second object.
  44      */
  45     public Pair(A first, B second) {
  46         fFirst = first;
  47         fSecond = second;
  48     }
  49
  50     /**
  51      * Constructor.
  52      */
  53     public Pair() {
  54         this(null, null);
  55     }
  56
  57     /**
  58      * Pair hash code.
  59      */
  60     @Override
  61     public int hashCode() {
  62         final int prime = 31;
  63         int result = 1;
  64         result = prime * result + ((fFirst == null) ? 0 : fFirst.hashCode());
  65         result = prime * result + ((fSecond == null) ? 0 : fSecond.hashCode());
  66         return result;
  67     }
  68
  69     /**
  70      * Object comparison.
  71      */
  72     @Override
  73     public boolean equals(Object obj) {
  74         if (this == obj) {
  75             return true;
  76         }
  77
  78         if (obj == null) {
  79             return false;
  80         }
  81
  82         if (getClass() != obj.getClass()) {
  83             return false;
  84         }
  85
  86         Pair<?, ?> other = (Pair<?, ?>) obj;
  87
  88         if (fFirst == null) {
  89             if (other.fFirst != null) {
  90                 return false;
  91             }
  92         } else if (!fFirst.equals(other.fFirst)) {
  93             return false;
  94         }
  95         if (fSecond == null) {
  96             if (other.fSecond != null) {
  97                 return false;
  98             }
  99         } else if (!fSecond.equals(other.fSecond)) {
 100             return false;
 101         }
 102         return true;
 103     }
 104
 105     /**
 106      * Object to string.
 107      */
 108     @Override
 109     public String toString() {
 110         return "(" + fFirst + ", " + fSecond + ")";  //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 111     }
 112
 113     /**
 114      * Returns a reference to the pair's first object.
 115      * @return A reference to the pair's first object.
 116      */
 117     public A getFirst() {
 118         return fFirst;
 119     }
 120
 121     /**
 122      * Sets the pair's first object.
 123      * @param first
 124      *            The pair's first object.
 125      */
 126     public void setFirst(A first) {
 127         fFirst = first;
 128     }
 129
 130     /**
 131      * Returns a reference to the pair's second object.
 132      * @return A reference to the pair's second object.
 133      */
 134     public B getSecond() {
 135         return fSecond;
 136     }
 137
 138     /**
 139      * Sets the pair's second object.
 140      * @param second
 141      *            The pair's second object.
 142      */
 143     public void setSecond(B second) {
 144         fSecond = second;
 145     }
 146 }