org.apache.camel.dataformat.tarfile.TarIterator.java Source code

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Here is the source code for org.apache.camel.dataformat.tarfile.TarIterator.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 org.apache.camel.dataformat.tarfile;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;

import org.apache.camel.Exchange;
import org.apache.camel.Message;
import org.apache.camel.RuntimeCamelException;
import org.apache.camel.impl.DefaultMessage;
import org.apache.camel.util.IOHelper;
import org.apache.commons.compress.archivers.ArchiveException;
import org.apache.commons.compress.archivers.ArchiveInputStream;
import org.apache.commons.compress.archivers.ArchiveStreamFactory;
import org.apache.commons.compress.archivers.tar.TarArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The Iterator which can go through the TarArchiveInputStream according to TarArchiveEntry
 * Based on ZipIterator from camel-zipfile component
 */
public class TarIterator implements Iterator<Message>, Closeable {
    static final Logger LOGGER = LoggerFactory.getLogger(TarIterator.class);

    private final Message inputMessage;
    private TarArchiveInputStream tarInputStream;
    private Message parent;

    public TarIterator(Message inputMessage, InputStream inputStream) {
        this.inputMessage = inputMessage;
        //InputStream inputStream = inputMessage.getBody(InputStream.class);

        if (inputStream instanceof TarArchiveInputStream) {
            tarInputStream = (TarArchiveInputStream) inputStream;
        } else {
            try {
                ArchiveInputStream input = new ArchiveStreamFactory()
                        .createArchiveInputStream(ArchiveStreamFactory.TAR, new BufferedInputStream(inputStream));
                tarInputStream = (TarArchiveInputStream) input;
            } catch (ArchiveException e) {
                throw new RuntimeException(e.getMessage(), e);
            }
        }
        parent = null;
    }

    @Override
    public boolean hasNext() {
        try {
            if (tarInputStream == null) {
                return false;
            }
            boolean availableDataInCurrentEntry = (tarInputStream.available() > 0);
            if (!availableDataInCurrentEntry) {
                // advance to the next entry.
                parent = getNextElement();
                // check if there are more data.
                //availableDataInCurrentEntry = (tarInputStream.available() > 1);
                // if there are not more data, close the stream.
                //if (!availableDataInCurrentEntry) {
                //    tarInputStream.close();
                //}
                if (parent == null) {
                    tarInputStream.close();
                    availableDataInCurrentEntry = false;
                } else {
                    availableDataInCurrentEntry = true;
                }
            }
            return availableDataInCurrentEntry;
        } catch (IOException exception) {
            //Just wrap the IOException as CamelRuntimeException
            throw new RuntimeCamelException(exception);
        }
    }

    @Override
    public Message next() {
        if (parent == null) {
            parent = getNextElement();
        }
        Message answer = parent;
        parent = null;
        checkNullAnswer(answer);

        return answer;
    }

    private Message getNextElement() {
        Message answer = null;

        if (tarInputStream != null) {
            try {
                TarArchiveEntry current = getNextEntry();

                if (current != null) {
                    LOGGER.debug("read tarEntry {}", current.getName());
                    answer = new DefaultMessage();
                    answer.getHeaders().putAll(inputMessage.getHeaders());
                    answer.setHeader("tarFileName", current.getName());
                    answer.setHeader(Exchange.FILE_NAME, current.getName());
                    if (current.getSize() > 0) {
                        answer.setBody(new TarInputStreamWrapper(tarInputStream));
                    } else {
                        // Workaround for the case when the entry is zero bytes big
                        answer.setBody(new ByteArrayInputStream(new byte[0]));
                    }
                    return answer;
                } else {
                    LOGGER.trace("close tarInputStream");
                }
            } catch (IOException exception) {
                //Just wrap the IOException as CamelRuntimeException
                throw new RuntimeCamelException(exception);
            }
        }

        return answer;
    }

    public void checkNullAnswer(Message answer) {
        if (answer == null && tarInputStream != null) {
            IOHelper.close(tarInputStream);
            tarInputStream = null;
        }
    }

    private TarArchiveEntry getNextEntry() throws IOException {
        TarArchiveEntry entry;

        while ((entry = tarInputStream.getNextTarEntry()) != null) {
            if (!entry.isDirectory()) {
                return entry;
            }
        }

        return null;
    }

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

    @Override
    public void close() throws IOException {
        if (tarInputStream != null) {
            tarInputStream.close();
            tarInputStream = null;
        }
    }
}