45 lines
1.2 KiB
Java
45 lines
1.2 KiB
Java
// understandingcollections/MapEntry.java
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// (c)2016 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
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// A simple Map.Entry for sample Map implementations
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import java.util.*;
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public class MapEntry<K, V> implements Map.Entry<K, V> {
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private K key;
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private V value;
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public MapEntry(K key, V value) {
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this.key = key;
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this.value = value;
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}
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@Override
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public K getKey() { return key; }
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@Override
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public V getValue() { return value; }
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@Override
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public V setValue(V v) {
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V result = value;
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value = v;
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return result;
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}
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@Override
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public int hashCode() {
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return (key==null ? 0 : key.hashCode()) ^
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(value==null ? 0 : value.hashCode());
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}
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@Override
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public boolean equals(Object o) {
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if(!(o instanceof MapEntry)) return false;
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@SuppressWarnings("unchecked")
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MapEntry<K, V> me = (MapEntry<K, V>)o;
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return
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(key == null ? me.getKey() == null :
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key.equals(me.getKey()))
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&&
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(value == null ? me.getValue() == null :
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value.equals(me.getValue()));
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}
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@Override
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public String toString() { return key + "=" + value; }
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}
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