com.msopentech.odatajclient.engine.communication.request.batch.ODataBatchResponseManager.java Source code

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Here is the source code for com.msopentech.odatajclient.engine.communication.request.batch.ODataBatchResponseManager.java

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/**
 * 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 com.msopentech.odatajclient.engine.communication.request.batch;

import com.msopentech.odatajclient.engine.communication.header.ODataHeaders;
import com.msopentech.odatajclient.engine.communication.response.ODataBatchResponse;
import com.msopentech.odatajclient.engine.utils.ODataConstants;
import java.io.IOException;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Batch response manager class.
 */
public class ODataBatchResponseManager implements Iterator<ODataBatchResponseItem> {

    /**
     * Logger.
     */
    private static final Logger LOG = LoggerFactory.getLogger(ODataBatchResponseManager.class);

    /**
     * Batch response line iterator.
     */
    private final ODataBatchLineIterator batchLineIterator;

    /**
     * Batch boundary.
     */
    private final String batchBoundary;

    /**
     * Expected batch response items iterator.
     */
    private final Iterator<ODataBatchResponseItem> expectedItemsIterator;

    /**
     * Last retrieved batch response item.
     */
    private ODataBatchResponseItem current = null;

    /**
     * Constructor.
     *
     * @param res OData batch response.
     * @param expectedItems expected batch response items.
     */
    public ODataBatchResponseManager(final ODataBatchResponse res,
            final List<ODataBatchResponseItem> expectedItems) {
        try {
            this.expectedItemsIterator = expectedItems.iterator();
            this.batchLineIterator = new ODataBatchLineIterator(
                    IOUtils.lineIterator(res.getRawResponse(), ODataConstants.UTF8));

            // search for boundary
            batchBoundary = ODataBatchUtilities
                    .getBoundaryFromHeader(res.getHeader(ODataHeaders.HeaderName.contentType));
            LOG.debug("Retrieved batch response bondary '{}'", batchBoundary);
        } catch (IOException e) {
            LOG.error("Error parsing batch response", e);
            throw new IllegalStateException(e);
        }
    }

    /**
     * {@inheritDoc }
     */
    @Override
    public boolean hasNext() {
        return expectedItemsIterator.hasNext();
    }

    /**
     * {@inheritDoc }
     */
    @Override
    public ODataBatchResponseItem next() {
        if (current != null) {
            current.close();
        }

        if (!hasNext()) {
            throw new NoSuchElementException("No item found");
        }

        current = expectedItemsIterator.next();

        final Map<String, Collection<String>> nextItemHeaders = ODataBatchUtilities
                .nextItemHeaders(batchLineIterator, batchBoundary);

        switch (ODataBatchUtilities.getItemType(nextItemHeaders)) {
        case CHANGESET:
            if (!current.isChangeset()) {
                throw new IllegalStateException("Unexpected batch item");
            }

            current.initFromBatch(batchLineIterator, ODataBatchUtilities
                    .getBoundaryFromHeader(nextItemHeaders.get(ODataHeaders.HeaderName.contentType.toString())));
            break;

        case RETRIEVE:
            if (current.isChangeset()) {
                throw new IllegalStateException("Unexpected batch item");
            }

            current.initFromBatch(batchLineIterator, batchBoundary);
            break;
        default:
            throw new IllegalStateException("Expected item not found");
        }

        return current;
    }

    /**
     * Unsupported operation.
     */
    @Override
    public void remove() {
        throw new UnsupportedOperationException("Remove operation is not supported");
    }
}