GridIterator.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.ignite.internal.util.lang;

import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.util.GridSerializableIterator;

/**
 * Defines "rich" iterator interface that is also acts like lambda function and iterable.
 * @see GridIterable
 */
public interface GridIterator<T> extends Iterable<T>, GridSerializableIterator<T> {
    /**
     * This method is the same as {@link #hasNext()}, but allows for failure
     * with exception. Often iterators are used to iterate through values
     * that have not or have partially been received from remote nodes,
     * and need to account for possible network failures, rather than
     * just returning {@code false} out of {@link #hasNext()} method.
     *
     * @return {@code True} if iterator contains more elements.
     * @throws IgniteCheckedException If no more elements can be returned due
     *      to some failure, like a network error for example.
     * @see Iterator#hasNext()
     */
    public boolean hasNextX() throws IgniteCheckedException;

    /**
     * This method is the same as {@link #next()}, but allows for failure
     * with exception. Often iterators are used to iterate through values
     * that have not or have partially been received from remote nodes,
     * and need to account for possible network failures, rather than
     * throwing {@link NoSuchElementException} runtime exception.s
     *
     * @return {@code True} if iterator contains more elements.
     * @throws NoSuchElementException If there are no more elements to
     *      return.
     * @throws IgniteCheckedException If no more elements can be returned due
     *      to some failure, like a network error for example.
     * @see Iterator#next()
     */
    public T nextX() throws IgniteCheckedException;

    /**
     * This method is the same as {@link #remove()}, but allows for failure
     * with exception.
     *
     * @throws IgniteCheckedException If failed.
     */
    public void removeX() throws IgniteCheckedException;
}