org.callimachusproject.io.CarOutputStream.java Source code

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Here is the source code for org.callimachusproject.io.CarOutputStream.java

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/*
   Copyright (c) 2011 3 Round Stones Inc, Some Rights Reserved
    
   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.callimachusproject.io;

import java.io.Closeable;
import java.io.FilterOutputStream;
import java.io.Flushable;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.compress.archivers.zip.Zip64Mode;
import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;

public class CarOutputStream implements Closeable, Flushable {
    private final ZipArchiveOutputStream zipStream;
    private final Set<String> closed = new HashSet<String>();

    public CarOutputStream(OutputStream out) throws IOException {
        this.zipStream = new ZipArchiveOutputStream(out);
        zipStream.setUseZip64(Zip64Mode.Always);
    }

    public OutputStream writeFolderEntry(String name, long time) throws IOException {
        if (name.charAt(name.length() - 1) != '/')
            throw new IllegalArgumentException("Folders must end with '/'");
        putArchiveEntry(name, time, null, MetaTypeExtraField.FOLDER);
        return openEntryStream();
    }

    public OutputStream writeResourceEntry(String name, long time, String type) throws IOException {
        putArchiveEntry(name, time, type, MetaTypeExtraField.RDF);
        return openEntryStream();
    }

    public OutputStream writeSchemaEntry(String name, long time, String type) throws IOException {
        putArchiveEntry(name, time, type, MetaTypeExtraField.RDFS);
        return openEntryStream();
    }

    public OutputStream writeFileEntry(String name, long time, String type) throws IOException {
        if (name.charAt(name.length() - 1) == '/')
            throw new IllegalArgumentException("Files cannot end with '/'");
        putArchiveEntry(name, time, type, MetaTypeExtraField.FILE);
        return openEntryStream();
    }

    @Override
    public void flush() throws IOException {
        zipStream.flush();
    }

    public void finish() throws IOException {
        zipStream.finish();
    }

    @Override
    public void close() throws IOException {
        zipStream.close();
    }

    private synchronized void putArchiveEntry(String name, long time, String type, MetaTypeExtraField mtype)
            throws IOException {
        if (!closed.add(name))
            throw new IllegalStateException("Entry has already been added: " + name);
        ZipArchiveEntry entry = new ZipArchiveEntry(name);
        entry.setTime(time);
        entry.addExtraField(mtype);
        if (type != null) {
            entry.addExtraField(new ContentTypeExtraField(type));
        }
        zipStream.putArchiveEntry(entry);
    }

    private FilterOutputStream openEntryStream() {
        return new FilterOutputStream(zipStream) {
            private boolean closed;

            public void close() throws IOException {
                if (!closed) {
                    closed = true;
                    zipStream.closeArchiveEntry();
                }
            }
        };
    }

}