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  */
  29 public class Pair<A, B> {
  30
  31     /**
  32      * A reference to the first object.
  33      */
  34     private final A fFirst;
  35     /**
  36      * A reference to the second object.
  37      */
  38     private final B fSecond;
  39
  40     /**
  41      * Constructor.
  42      * @param first
  43      *            The pair's first object.
  44      * @param second
  45      *            The pair's second object.
  46      */
  47     public Pair(A first, B second) {
  48         fFirst = first;
  49         fSecond = second;
  50     }
  51
  52
  53     /**
  54      * Returns a reference to the pair's first object.
  55      *
  56      * @return A reference to the pair's first object.
  57      */
  58     public A getFirst() {
  59         return fFirst;
  60     }
  61
  62     /**
  63      * Returns a reference to the pair's second object.
  64      *
  65      * @return A reference to the pair's second object.
  66      */
  67     public B getSecond() {
  68         return fSecond;
  69     }
  70
  71     @Override
  72     public int hashCode() {
  73         final int prime = 31;
  74         int result = 1;
  75         result = prime * result + fFirst.hashCode();
  76         result = prime * result + fSecond.hashCode();
  77         return result;
  78     }
  79
  80     @Override
  81     public boolean equals(@Nullable Object obj) {
  82         if (this == obj) {
  83             return true;
  84         }
  85
  86         if (obj == null) {
  87             return false;
  88         }
  89
  90         if (getClass() != obj.getClass()) {
  91             return false;
  92         }
  93
  94         Pair<?, ?> other = (Pair<?, ?>) obj;
  95
  96         if (!fFirst.equals(other.fFirst)) {
  97             return false;
  98         }
  99         if (!fSecond.equals(other.fSecond)) {
 100             return false;
 101         }
 102         return true;
 103     }
 104
 105     @Override
 106     public String toString() {
 107         return "(" + fFirst + ", " + fSecond + ")";  //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
 108     }
 109
 110 }