[Japi-cvs] SF.net SVN: japi:[1192] libs/util/trunk/src/prj/net/sf/japi/util/ HashMapWithDefault.java

[<chr...@us...>]

Revision: 1192
          http://japi.svn.sourceforge.net/japi/?rev=1192&view=rev
Author:   christianhujer
Date:     2009-02-26 14:29:00 +0000 (Thu, 26 Feb 2009)

Log Message:
-----------
Added class HashMapWithDefault.

Added Paths:
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    libs/util/trunk/src/prj/net/sf/japi/util/HashMapWithDefault.java

Added: libs/util/trunk/src/prj/net/sf/japi/util/HashMapWithDefault.java
===================================================================
--- libs/util/trunk/src/prj/net/sf/japi/util/HashMapWithDefault.java	                        (rev 0)
+++ libs/util/trunk/src/prj/net/sf/japi/util/HashMapWithDefault.java	2009-02-26 14:29:00 UTC (rev 1192)
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2009  Christian Hujer.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.sf.japi.util;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * HashMap implementation which provides default values for unmapped keys which can be distinct from <code>null</code>.
+ * @warning This map implementation violates the contract of {@link Map#get(Object)} regarding the return value.
+ * @author <a href="mailto:ch...@ri...">Christian Hujer</a>
+ * @param <K> Type for the map keys.
+ * @param <V> Type for the map values.
+ */
+@SuppressWarnings({"ClassExtendsConcreteCollection"})
+public class HashMapWithDefault<K, V> extends HashMap<K, V> {
+
+    /** Serial Version. */
+    private static final long serialVersionUID = 1L;
+
+    /** The default value to return if a key is not mapped.
+     * @serial include
+     */
+    // It is the responsibility of the user to choose a serializable V for a map that is serialized.
+    @SuppressWarnings({"NonSerializableFieldInSerializableClass"})
+    private V defaultValue;
+
+    /** Creates a HashMapWithDefault.
+     * @param defaultValue Value to be returned by {@link Map#get(Object)} for unmapped keys.
+     */
+    public HashMapWithDefault(final V defaultValue) {
+        this.defaultValue = defaultValue;
+    }
+
+    /** {@inheritDoc} */
+    @Override
+    public V get(final Object key) {
+        return containsKey(key) ? super.get(key) : defaultValue;
+    }
+}


Property changes on: libs/util/trunk/src/prj/net/sf/japi/util/HashMapWithDefault.java
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Added: svn:mime-type
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