Closer.java

/**
 * Licensed to jclouds, Inc. (jclouds) under one or more
 * contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  jclouds licenses this file
 * to you 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.jclouds.lifecycle;

import java.io.Closeable;
import java.io.IOException;
import java.util.Collections;
import java.util.List;

import javax.inject.Singleton;

import com.google.common.collect.Lists;

/**
 * This will close objects in the reverse order that they were added.
 * 
 * @author Adrian Cole
 */
@Singleton
public class Closer implements Closeable {
   // guice is single threaded. no need to lock this
   List<Closeable> methodsToClose = Lists.<Closeable> newArrayList();

   public void addToClose(Closeable toClose) {
      methodsToClose.add(toClose);
   }

   public void close() throws IOException {
      Collections.reverse(methodsToClose);
      for (Closeable toClose : methodsToClose) {
         toClose.close();
      }
   }
}