added CallableQueueCollector to consume all items from a IterableQueue

scm-core/src/main/java/sonia/scm/collect/CallableQueueCollector.java

@@ -0,0 +1,98 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.collect;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.collect.Lists;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.util.List;
+import java.util.concurrent.Callable;
+
+/**
+ * A {@link Callable} which consumes all items from a {@link QueueIterator} and 
+ * returns a list with all items from the queue.
+ *
+ * @author Sebastian Sdorra
+ * 
+ * @since 1.29
+ *
+ * @param <T> type of the queued items
+ */
+public class CallableQueueCollector<T> implements Callable<List<T>>
+{
+
+  /**
+   * the logger for CallableListComsumer
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(CallableQueueCollector.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs a new {@link CallableQueueCollector} from the given 
+   * {@link IterableQueue}.
+   *
+   * @param queue queue to collect
+   */
+  public CallableQueueCollector(IterableQueue<T> queue)
+  {
+    this.queue = queue;
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Creates a {@link List} from all items of the queue.
+   *
+   *
+   * @return {@link List} from all items of the queue
+   */
+  @Override
+  public List<T> call()
+  {
+    logger.trace("start collecting item from queue");
+
+    return Lists.newArrayList(queue);
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** queue to collect items from */
+  private IterableQueue<T> queue;
+}