Java example source code file (BucketIterator.java)

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Java - Java tags/keywords

bucketiterator, illegalstateexception, indeterminate, inputstream, list, objectlisting, override, s3downloader, string, unsupportedoperationexception, util

The BucketIterator.java Java example source code

/*
 *
 *  * Copyright 2015 Skymind,Inc.
 *  *
 *  *    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.deeplearning4j.aws.s3.reader;

import java.io.InputStream;
import java.util.Iterator;
import java.util.List;

import com.amazonaws.services.s3.model.ObjectListing;
import com.amazonaws.services.s3.model.S3ObjectSummary;
/**
 * Iterator over individual S3 bucket
 * @author Adam Gibson
 *
 */
public class BucketIterator implements Iterator<InputStream> {

	private S3Downloader s3;
	private String bucket;
	private ObjectListing currList;
	private List<S3ObjectSummary> currObjects;
	private int currObject;




	public BucketIterator(String bucket) {
		this(bucket,null);

	}


	public BucketIterator(String bucket,S3Downloader s3) {
		this.bucket = bucket;

		if(s3 == null)
			this.s3 = new S3Downloader();
        else
            this.s3 = s3;
		currList = s3.listObjects(bucket);
		currObjects = currList.getObjectSummaries();

	}



	@Override
	public boolean hasNext() {
	    return currObject < currObjects.size();
	}

	@Override
	public InputStream next() {
		if(currObject < currObjects.size()) {
			InputStream ret = s3.objectForKey(bucket, currObjects.get(currObject).getKey());
			currObject++;
			return ret;
		}
		else if(currList.isTruncated()) {
			currList = s3.nextList(currList);
			currObjects = currList.getObjectSummaries();
			currObject = 0;

			InputStream ret = s3.objectForKey(bucket, currObjects.get(currObject).getKey());

			currObject++;
			return ret;
		}


		throw new IllegalStateException("Indeterminate state");
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException();
	}


}