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

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2015 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  *   Alexandre Montplaisir - Made non-null and immutable
  14  *******************************************************************************/
  15 package org.eclipse.tracecompass.tmf.core.util;
  16
  17 import org.eclipse.jdt.annotation.Nullable;
  18
  19 /**
  20  * Pair utility class, encapsulates a pair of objects.
  21  *
  22  * @param <A>
  23  *            The type of the first object.
  24  * @param <B>
  25  *            The type of the second object.
  26  *
  27  * @author Philippe Sawicki
  28  * @since 2.0
  29  */
  30 public class Pair<A, B> {
  31
  32     /**
  33      * A reference to the first object.
  34      */
  35     private final A fFirst;
  36     /**
  37      * A reference to the second object.
  38      */
  39     private final B fSecond;
  40
  41     /**
  42      * Constructor.
  43      * @param first
  44      *            The pair's first object.
  45      * @param second
  46      *            The pair's second object.
  47      */
  48     public Pair(A first, B second) {
  49         fFirst = first;
  50         fSecond = second;
  51     }
  52
  53
  54     /**
  55      * Returns a reference to the pair's first object.
  56      *
  57      * @return A reference to the pair's first object.
  58      */
  59     public A getFirst() {
  60         return fFirst;
  61     }
  62
  63     /**
  64      * Returns a reference to the pair's second object.
  65      *
  66      * @return A reference to the pair's second object.
  67      */
  68     public B getSecond() {
  69         return fSecond;
  70     }
  71
  72     @Override
  73     public int hashCode() {
  74         final int prime = 31;
  75         int result = 1;
  76         result = prime * result + fFirst.hashCode();
  77         result = prime * result + fSecond.hashCode();
  78         return result;
  79     }
  80
  81     @Override
  82     public boolean equals(@Nullable Object obj) {
  83         if (this == obj) {
  84             return true;
  85         }
  86
  87         if (obj == null) {
  88             return false;
  89         }
  90
  91         if (getClass() != obj.getClass()) {
  92             return false;
  93         }
  94
  95         Pair<?, ?> other = (Pair<?, ?>) obj;
  96
  97         if (!fFirst.equals(other.fFirst)) {
  98             return false;
  99         }
 100         if (!fSecond.equals(other.fSecond)) {
 101             return false;
 102         }
 103         return true;
 104     }
 105
 106     @Override
 107     public String toString() {
 108         return "(" + fFirst + ", " + fSecond + ")";  //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 109     }
 110
 111 }