/*
 * Copyright 2004-2010 the Seasar Foundation and the Others.
 *
 * 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.slim3.controller.upload;

import java.io.IOException;

import javax.servlet.http.HttpServletRequest;

/**
 * An iterator, as returned by
 * {@link FileUpload#getItemIterator(HttpServletRequest)}.
 * 
 * @author higa
 * @since 1.0.0
 * 
 */
public interface FileItemIterator {

    /**
     * Returns, whether another instance of {@link FileItemStream} is available.
     * 
     * @throws FileUploadException
     *             Parsing or processing the file item failed.
     * @throws IOException
     *             Reading the file item failed.
     * @return True, if one or more additional file items are available,
     *         otherwise false.
     */
    boolean hasNext() throws FileUploadException, IOException;

    /**
     * Returns the next available {@link FileItemStream}.
     * 
     * @throws java.util.NoSuchElementException
     *             No more items are available. Use {@link #hasNext()} to
     *             prevent this exception.
     * @throws FileUploadException
     *             Parsing or processing the file item failed.
     * @throws IOException
     *             Reading the file item failed.
     * @return FileItemStream instance, which provides access to the next file
     *         item.
     */
    FileItemStream next() throws FileUploadException, IOException;
}