MapOverEnd.java

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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/* @test
 * @bug 4463036
 * @summary Check if file mapping extends beyond end of file
 * @run main/othervm MapOverEnd
 */

import java.nio.*;
import java.nio.channels.*;
import java.io.*;

public class MapOverEnd {
    public static void main (String [] args) throws Exception {
        File blah = File.createTempFile("blah", null);
        blah.deleteOnExit();
        RandomAccessFile raf = new RandomAccessFile (blah, "rw");
        FileChannel fc = raf.getChannel();
        MappedByteBuffer map = fc.map(FileChannel.MapMode.READ_WRITE, 0, 2048);
        fc.close();
        double current = map.getDouble (50);
        map.putDouble (50, current+0.1d);
        map.force();
    }
}