Merge pull request #625 from guusdk/OF-1156

Revert "OF-1156: Be consistent with the contents of DefaultCache ..."

src/java/org/jivesoftware/util/cache/Cache.java

@@ -30,7 +30,7 @@ package org.jivesoftware.util.cache;
  *
  * If the cache does grow too large, objects will be removed such that those
  * that are accessed least frequently are removed first. Because expiration
- * happens automatically, the cache makes <b>no</b> guarantee as to how long
+ * happens automatically, the cache makes <b>no</b> gaurantee as to how long
  * an object will remain in cache after it is put in.<p>
  *
  * Optionally, a maximum lifetime for all objects can be specified. In that
@@ -41,9 +41,6 @@ package org.jivesoftware.util.cache;
  *
  * All cache operations are thread safe.<p>
  *
- * Note that neither keys or values can be null; A {@link NullPointerException}
- * will be thrown attempting to place or retrieve null values in to the cache.
- *
  * @see Cacheable
  */
 public interface Cache<K,V> extends java.util.Map<K,V> {

src/java/org/jivesoftware/util/cache/DefaultCache.java

@@ -59,10 +59,7 @@ import org.slf4j.LoggerFactory;
  */
 public class DefaultCache<K, V> implements Cache<K, V> {
 
-    private static final String NULL_KEY_IS_NOT_ALLOWED = "Null key is not allowed!";
-    private static final String NULL_VALUE_IS_NOT_ALLOWED = "Null value is not allowed!";
-
-    private static final Logger Log = LoggerFactory.getLogger(DefaultCache.class);
+	private static final Logger Log = LoggerFactory.getLogger(DefaultCache.class);
 
     /**
      * The map the keys and values are stored in.
@@ -136,8 +133,6 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
     @Override
     public synchronized V put(K key, V value) {
-        checkNotNull(key, NULL_KEY_IS_NOT_ALLOWED);
-        checkNotNull(value, NULL_VALUE_IS_NOT_ALLOWED);
         // Delete an old entry if it exists.
         V answer = remove(key);
 
@@ -179,7 +174,6 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
     @Override
     public synchronized V get(Object key) {
-        checkNotNull(key, NULL_KEY_IS_NOT_ALLOWED);
         // First, clear all entries that have been in cache longer than the
         // maximum defined age.
         deleteExpiredEntries();
@@ -206,7 +200,6 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
     @Override
     public synchronized V remove(Object key) {
-        checkNotNull(key, NULL_KEY_IS_NOT_ALLOWED);
         DefaultCache.CacheObject<V> cacheObject = map.get(key);
         // If the object is not in cache, stop trying to remove it.
         if (cacheObject == null) {
@@ -292,7 +285,6 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
         @Override
         public boolean contains(Object o) {
-            checkNotNull(o, NULL_KEY_IS_NOT_ALLOWED);
             Iterator<V> it = iterator();
             while (it.hasNext()) {
                 if (it.next().equals(o)) {
@@ -399,7 +391,6 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
     @Override
     public boolean containsKey(Object key) {
-        checkNotNull(key, NULL_KEY_IS_NOT_ALLOWED);
         // First, clear all entries that have been in cache longer than the
         // maximum defined age.
         deleteExpiredEntries();
@@ -418,11 +409,14 @@ public class DefaultCache<K, V> implements Cache<K, V> {
 
     @Override
     public boolean containsValue(Object value) {
-        checkNotNull(value, NULL_VALUE_IS_NOT_ALLOWED);
         // First, clear all entries that have been in cache longer than the
         // maximum defined age.
         deleteExpiredEntries();
 
+        if(value == null) {
+            return containsNullValue();
+        }
+
         Iterator it = values().iterator();
         while(it.hasNext()) {
             if(value.equals(it.next())) {
@@ -432,6 +426,16 @@ public class DefaultCache<K, V> implements Cache<K, V> {
         return false;
     }
 
+    private boolean containsNullValue() {
+        Iterator it = values().iterator();
+        while(it.hasNext()) {
+            if(it.next() == null) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     @Override
     public Set<Entry<K, V>> entrySet() {
         // First, clear all entries that have been in cache longer than the
@@ -699,10 +703,4 @@ public class DefaultCache<K, V> implements Cache<K, V> {
             this.size = size;
         }
     }
-
-    private void checkNotNull(final Object argument, final String message) {
-        if (argument == null) {
-            throw new NullPointerException(message);
-        }
-    }
 }