CompressedPixelDataOutput.java

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 * The Original Code is part of dcm4che, an implementation of DICOM(TM) in
 * Java(TM), hosted at https://github.com/gunterze/dcm4che.
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 * The Initial Developer of the Original Code is
 * Agfa Healthcare.
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package org.dcm4chee.archive.wado;

import org.dcm4che3.data.BulkData;
import org.dcm4che3.data.Fragments;
import org.dcm4che3.util.SafeClose;
import org.dcm4che3.util.StreamUtils;

import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.StreamingOutput;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;

/**
 * Streams compressed pixel data.
 *
 * @author Gunter Zeilinger <gunterze@gmail.com>
 */
public class CompressedPixelDataOutput implements StreamingOutput {

    private final Fragments fragments;

    public CompressedPixelDataOutput(Fragments fragments) {
        this.fragments = fragments;
    }

    @Override
    public void write(OutputStream out) throws IOException,
            WebApplicationException {
        Iterator<Object> iter = fragments.iterator();
        iter.next(); // skip frame offset table
        BulkData fragment = (BulkData) iter.next();
        InputStream in = fragment.openStream();
        try {
            StreamUtils.copy(in, out, fragment.length());
            while (iter.hasNext()) {
                long streamPosition = fragment.offset() + fragment.length();
                fragment = (BulkData) iter.next();
                StreamUtils.skipFully(in, fragment.offset() - streamPosition);
                StreamUtils.copy(in, out, fragment.length());
            }
        } finally {
            SafeClose.close(in);
        }
    }

}