Migration to maven almost complete. At least everything builds and works

[utils] / support / src / org / wamblee / cache / CachedObject.java

diff --git a/support/src/org/wamblee/cache/CachedObject.java b/support/src/org/wamblee/cache/CachedObject.java
deleted file mode 100644 (file)
index 787bc87..0000000
--- a/support/src/org/wamblee/cache/CachedObject.java
+++ /dev/null
@@ -1,129 +0,0 @@
-/*
- * Copyright 2005 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.
- * You may obtain a copy of the License at
- * 
- *      http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * 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;
-
-/**
- * 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
-     */
-    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;
-
-    /**
-     * Key of the object in the cache.
-     */
-    private KeyType _objectKey;
-
-    /**
-     * Computation used to obtain the object if it is not found in the cache.
-     */
-    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.
-     */
-    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.
-     */
-    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;
-    }
-
-    /**
-     * Invalidates the cache for the object so that it is recomputed the next
-     * time it is requested.
-     * 
-     */
-    public void invalidate() {
-        _cache.remove(_objectKey);
-    }
-
-    /**
-     * Gets the cache.
-     * 
-     * @return Cache.
-     */
-    public Cache getCache() {
-        return _cache;
-    }
-}