X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;f=support%2Fsrc%2Forg%2Fwamblee%2Fcache%2FCachedObject.java;h=787bc8703d015c685041729192ab9441b7e93172;hb=07cedd3f0730646ea35a7f668b3e1e872a4605d9;hp=8a4772f8fed557efd6d5c717b6a7d90325ded89a;hpb=fb4deb496257c78d4711aab48191dd9a0678798a;p=utils

diff --git a/support/src/org/wamblee/cache/CachedObject.java b/support/src/org/wamblee/cache/CachedObject.java
index 8a4772f8..787bc870 100644
--- a/support/src/org/wamblee/cache/CachedObject.java
+++ b/support/src/org/wamblee/cache/CachedObject.java
@@ -12,7 +12,7 @@
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
- */ 
+ */
 
 package org.wamblee.cache;
 
@@ -21,91 +21,109 @@ import java.io.Serializable;
 import org.apache.log4j.Logger;
 
 /**
- * Represents a cached object. The object is either retrieved from the cache if the cache
- * has it, or a call back is invoked to get the object (and put it in the cache). 
+ * Represents a cached object. The object is either retrieved from the cache if
+ * the cache has it, or a call back is invoked to get the object (and put it in
+ * the cache).
  */
 public class CachedObject<KeyType extends Serializable, ValueType extends Serializable> {
-    
+
     private static final Logger LOGGER = Logger.getLogger(CachedObject.class);
-    
+
     /**
-     * Callback invoked to compute an object if it was not found in the cache. 
-     * @param <T> Type of the object 
+     * Callback invoked to compute an object if it was not found in the cache.
+     * 
+     * @param <T>
+     *            Type of the object
      */
     public static interface Computation<Key extends Serializable, Value extends Serializable> {
         /**
-         * Gets the object. Called when the object is not in the cache. 
-         * @param aObjectKey Id of the object in the cache. 
-         * @return Object, must be non-null. 
+         * Gets the object. Called when the object is not in the cache.
+         * 
+         * @param aObjectKey
+         *            Id of the object in the cache.
+         * @return Object, must be non-null.
          */
-        Value getObject(Key aObjectKey); 
+        Value getObject(Key aObjectKey);
     }
-    
+
     /**
-     * Cache to use. 
+     * Cache to use.
      */
     private Cache<KeyType, ValueType> _cache;
-    
+
     /**
-     * Key of the object in the cache. 
+     * Key of the object in the cache.
      */
-    private KeyType _objectKey; 
-    
+    private KeyType _objectKey;
+
     /**
-     * Computation used to obtain the object if it is not found in the cache. 
+     * Computation used to obtain the object if it is not found in the cache.
      */
-    private Computation<KeyType, ValueType> _computation; 
-    
+    private Computation<KeyType, ValueType> _computation;
+
     /**
-     * Constructs the cached object. 
-     * @param aCache Cache to use. 
-     * @param aObjectKey Key of the object in the cache. 
-     * @param aComputation Computation to get the object in case the object is not in the cache.
+     * Constructs the cached object.
+     * 
+     * @param aCache
+     *            Cache to use.
+     * @param aObjectKey
+     *            Key of the object in the cache.
+     * @param aComputation
+     *            Computation to get the object in case the object is not in the
+     *            cache.
      */
-    public CachedObject(Cache<KeyType,ValueType> aCache, KeyType aObjectKey,  Computation<KeyType,ValueType> aComputation) {
-        _cache = aCache; 
-        _objectKey = aObjectKey; 
-        _computation = aComputation; 
+    public CachedObject(Cache<KeyType, ValueType> aCache, KeyType aObjectKey,
+            Computation<KeyType, ValueType> aComputation) {
+        _cache = aCache;
+        _objectKey = aObjectKey;
+        _computation = aComputation;
     }
-    
+
     /**
-     * Gets the object. Since the object is cached, different calls to this method may return 
-     * different objects. 
-     * @return Object. 
+     * Gets the object. Since the object is cached, different calls to this
+     * method may return different objects.
+     * 
+     * @return Object.
      */
-    public ValueType get() { 
-        ValueType object = (ValueType)_cache.get(_objectKey); // the used cache is thread safe. 
-        if ( object == null ) {
-            // synchronize the computation to make sure that the object is only computed
-            // once when multiple concurrent threads detect that the entry must be
-            // recomputed. 
-            synchronized (this) { 
-               object = (ValueType)_cache.get(_objectKey); 
-               if ( object == null ) { 
-                   // No other thread did a recomputation so we must do this now.
-                   LOGGER.debug("Refreshing cache for '" + _objectKey + "'"); 
-                   object = _computation.getObject(_objectKey);
-                   _cache.put(_objectKey, object); 
-               }
+    public ValueType get() {
+        ValueType object = (ValueType) _cache.get(_objectKey); // the used
+                                                                // cache is
+                                                                // thread safe.
+        if (object == null) {
+            // synchronize the computation to make sure that the object is only
+            // computed
+            // once when multiple concurrent threads detect that the entry must
+            // be
+            // recomputed.
+            synchronized (this) {
+                object = (ValueType) _cache.get(_objectKey);
+                if (object == null) {
+                    // No other thread did a recomputation so we must do this
+                    // now.
+                    LOGGER.debug("Refreshing cache for '" + _objectKey + "'");
+                    object = _computation.getObject(_objectKey);
+                    _cache.put(_objectKey, object);
+                }
             }
         }
-        return object;     
+        return object;
     }
-    
+
     /**
-     * Invalidates the cache for the object so that it is recomputed the next 
-     * time it is requested. 
-     *
+     * Invalidates the cache for the object so that it is recomputed the next
+     * time it is requested.
+     * 
      */
-    public void invalidate() { 
+    public void invalidate() {
         _cache.remove(_objectKey);
     }
-    
+
     /**
-     * Gets the cache. 
-     * @return Cache. 
+     * Gets the cache.
+     * 
+     * @return Cache.
      */
-    public Cache getCache() { 
-        return _cache; 
+    public Cache getCache() {
+        return _cache;
     }
 }