org.jvnet.mimepull.DataFile Maven / Gradle / Ivy

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Provides a streaming API to access attachments parts in a MIME message.
There is a newer version: 1.6
/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package org.jvnet.mimepull;

import java.io.*;

/**
 * Use {@link RandomAccessFile} for concurrent access of read
 * and write partial part's content.
 *
 * @author Kohsuke Kawaguchi
 * @author Jitendra Kotamraju
 */
final class DataFile {
    private WeakDataFile weak;
    private long writePointer;

    DataFile(File file) {
        writePointer=0;
        weak = new WeakDataFile(this, file);
    }

    /**
     *
     */
    void close() {
        weak.close();
    }

    /**
     * Read data from the given file pointer position.
     *
     * @param pointer read position
     * @param buf that needs to be filled
     * @param offset the start offset of the data.
     * @param length of data that needs to be read
     */
    synchronized void read(long pointer, byte[] buf, int offset, int length ) {
        weak.read(pointer, buf, offset, length);
    }

    void renameTo(File f) {
        weak.renameTo(f);
    }

    /**
     * Write data to the file
     *
     * @param data that needs to written to a file
     * @param offset start offset in the data
     * @param length no bytes to write
     * @return file pointer before the write operation(or at which the
     *         data is written)
     */
    synchronized long writeTo(byte[] data, int offset, int length) {
        long temp = writePointer;
        writePointer = weak.writeTo(writePointer, data, offset, length);
        return temp;
    }

}