cassandra-trunk/src/java/org/apache/cassandra/utils/CloseableIterator.java
/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.cassandra.utils;

import java.util.Iterator;
import java.util.NoSuchElementException;

// so we can instantiate anonymous classes implementing both interfaces
public interface CloseableIterator<T> extends Iterator<T>, AutoCloseable
{
    public void close();

    public static <T> CloseableIterator<T> wrap(Iterator<T> iter)
    {
        return new CloseableIterator<T>()
        {
            public void close()
            {
                // noop
            }

            public boolean hasNext()
            {
                return iter.hasNext();
            }

            public T next()
            {
                return iter.next();
            }
        };
    }

    public static <T> CloseableIterator<T> empty()
    {
        return new CloseableIterator<T>()
        {
            public void close()
            {
                // noop
            }

            public boolean hasNext()
            {
                return false;
            }

            public T next()
            {
                throw new NoSuchElementException();
            }
        };
    }

}
