com.gamesalutes.utils.StreamDataSource.java Source code

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Here is the source code for com.gamesalutes.utils.StreamDataSource.java

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/*
 * Copyright (c) 2013 Game Salutes.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser Public License v3
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 * 
 * Contributors:
 *     Game Salutes - Repackaging and modifications of original work under University of Chicago and Apache License 2.0 shown below
 * 
 * Repackaging from edu.uchicago.nsit.iteco.utils to com.gamesalutes.utils
 * 
 * Copyright 2008 - 2011 University of Chicago
 * 
 * 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.
 ******************************************************************************/
/* Copyright 2008 - 2009 University of Chicago
 * 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 com.gamesalutes.utils;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;

import javax.activation.DataSource;
import org.apache.commons.codec.binary.Base64;

/**
 * <code>DataSource</code> for an arbitrary stream.  MIME type will be "application/octet-stream" unless
 * indicated otherwise.
 * 
 * @author Justin Montgomery
 * @version $Id:$
 */
public final class StreamDataSource implements DataSource {

    private final StreamFactory creator;
    private final String name;
    private final String contentType;

    /**
     * Creates a new input stream and new output stream on demand that
     * encapsulates the desired content.
     * 
     * @author Justin Montgomery
     * @version $Id:$
     */
    public interface StreamFactory {
        InputStream newInputStream(String name) throws IOException;

        OutputStream newOutputStream(String name) throws IOException;
    }

    public StreamDataSource(StreamFactory creator, String name) {
        this(creator, name, null);
    }

    public StreamDataSource(StreamFactory creator, String name, String contentType) {
        if (creator == null)
            throw new NullPointerException("creator");
        this.creator = creator;
        this.name = name;
        if (contentType != null)
            this.contentType = contentType;
        else
            this.contentType = "application/octet-stream";
    }

    /* (non-Javadoc)
     * @see javax.activation.DataSource#getContentType()
     */
    public String getContentType() {
        return contentType;
    }

    /* (non-Javadoc)
     * @see javax.activation.DataSource#getInputStream()
     */
    public InputStream getInputStream() throws IOException {
        return creator.newInputStream(name);
    }

    /* (non-Javadoc)
     * @see javax.activation.DataSource#getName()
     */
    public String getName() {
        return name;
    }

    /* (non-Javadoc)
     * @see javax.activation.DataSource#getOutputStream()
     */
    public OutputStream getOutputStream() throws IOException {
        return creator.newOutputStream(name);
    }

    /**
     * Default implementation of stream creator that only supports input streams and stores its content in
     * memory so that {@link #newInputStream(String)} can return an input stream that points to the position of the
     * content at the time this object was constructed.
     * 
     * @author Justin Montgomery
     * @version $Id:$
     */
    public static class DefaultStreamFactory implements StreamFactory {
        private final ByteBuffer data;

        public DefaultStreamFactory(InputStream in, boolean base64Encode) throws IOException {
            if (in == null)
                throw new NullPointerException("in");
            if (!base64Encode) {
                data = ByteUtils.readBytes(in, null);
            } else {
                byte[] ba = ByteUtils.readBytes(in);
                ba = Base64.encodeBase64(ba);
                data = ByteBuffer.wrap(ba);
            }
        }

        /* (non-Javadoc)
         * @see com.gamesalutes.utils.StreamDataSource.StreamCreator#newInputStream(java.lang.String)
         */
        public InputStream newInputStream(String name) {
            ByteBuffer b = data.duplicate();
            b.rewind();
            return new ByteBufferInputStream(b);
        }

        /* (non-Javadoc)
         * @see com.gamesalutes.utils.StreamDataSource.StreamCreator#newOutputStream(java.lang.String)
         */
        public OutputStream newOutputStream(String name) {
            throw new UnsupportedOperationException();
        }

    }

}