X-Git-Url: http://wamblee.org/gitweb/?a=blobdiff_plain;f=support%2Fgeneral%2Fsrc%2Fmain%2Fjava%2Forg%2Fwamblee%2Fcache%2FCachedObject.java;h=3d200b5ad38d1ba9818c9d4c3d53ebb11f85eaf0;hb=17775e14ecfb286e59f67117e5cee7e21e95ab1f;hp=58daf8c918ee3c53ff4ade7d31db0ee9d90fe279;hpb=32a62ca2c752e33a7873ac868a7a1f289caedcd4;p=utils

diff --git a/support/general/src/main/java/org/wamblee/cache/CachedObject.java b/support/general/src/main/java/org/wamblee/cache/CachedObject.java
index 58daf8c9..3d200b5a 100644
--- a/support/general/src/main/java/org/wamblee/cache/CachedObject.java
+++ b/support/general/src/main/java/org/wamblee/cache/CachedObject.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2005 the original author or authors.
+ * Copyright 2005-2010 the original author or authors.
  * 
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -12,56 +12,38 @@
  * 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;
 
-import java.io.Serializable;
-
 import org.apache.log4j.Logger;
 
+import java.io.Serializable;
+
 /**
  * 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).
- *
+ * 
  * @author Erik Brakkee
+ * 
  */
 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
-     */
-    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.
-         */
-        Value getObject(Key aObjectKey);
-    }
-
     /**
      * Cache to use.
      */
-    private Cache<KeyType, ValueType> _cache;
+    private Cache<KeyType, ValueType> 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.
      */
-    private Computation<KeyType, ValueType> _computation;
+    private Computation<KeyType, ValueType> computation;
 
     /**
      * Constructs the cached object.
@@ -75,10 +57,10 @@ public class CachedObject<KeyType extends Serializable, ValueType extends Serial
      *            cache.
      */
     public CachedObject(Cache<KeyType, ValueType> aCache, KeyType aObjectKey,
-            Computation<KeyType, ValueType> aComputation) {
-        _cache = aCache;
-        _objectKey = aObjectKey;
-        _computation = aComputation;
+        Computation<KeyType, ValueType> aComputation) {
+        cache = aCache;
+        objectKey = aObjectKey;
+        computation = aComputation;
     }
 
     /**
@@ -88,9 +70,10 @@ public class CachedObject<KeyType extends Serializable, ValueType extends Serial
      * @return Object.
      */
     public ValueType get() {
-        ValueType object = (ValueType) _cache.get(_objectKey); // the used
-                                                                // cache is
-                                                                // thread safe.
+        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
@@ -98,26 +81,27 @@ public class CachedObject<KeyType extends Serializable, ValueType extends Serial
             // be
             // recomputed.
             synchronized (this) {
-                object = (ValueType) _cache.get(_objectKey);
+                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);
+                    LOGGER.debug("Refreshing cache for '" + objectKey + "'");
+                    object = computation.getObject(objectKey);
+                    cache.put(objectKey, object);
                 }
             }
         }
+
         return object;
     }
 
     /**
      * Invalidates the cache for the object so that it is recomputed the next
      * time it is requested.
-     * 
      */
     public void invalidate() {
-        _cache.remove(_objectKey);
+        cache.remove(objectKey);
     }
 
     /**
@@ -126,6 +110,24 @@ public class CachedObject<KeyType extends Serializable, ValueType extends Serial
      * @return Cache.
      */
     public Cache getCache() {
-        return _cache;
+        return cache;
+    }
+
+    /**
+     * 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.
+         */
+        Value getObject(Key aObjectKey);
     }
 }