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import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.DataInputStream;

import java.io.DataOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.RandomAccessFile;

import java.nio.ByteBuffer;

import java.nio.channels.FileChannel;

import com.googlecode.javaewah.datastructure.BitSet;

import com.googlecode.javaewah.datastructure.ImmutableBitSet;

public class BitSetMemoryMappingExample {

public static void main(String[] args) throws IOException {

File tmpfile = File.createTempFile("javaewah", "bin");

tmpfile.deleteOnExit();

final FileOutputStream fos = new FileOutputStream(tmpfile);

BitSet Bitmap = BitSet.bitmapOf(0, 2, 55, 64, 512);

System.out.println("Created the bitmap " + Bitmap);

Bitmap.serialize(new DataOutputStream(fos));

long totalcount = fos.getChannel().position();

System.out.println("Serialized total count = " + totalcount + " bytes");

fos.close();

RandomAccessFile memoryMappedFile = new RandomAccessFile(tmpfile, "r");

ByteBuffer bb = memoryMappedFile.getChannel().map(

FileChannel.MapMode.READ_ONLY, 0, totalcount);

ImmutableBitSet mapped = new ImmutableBitSet(bb.asLongBuffer());

System.out.println("Mapped the bitmap " + mapped);

memoryMappedFile.close();

if (!mapped.equals(Bitmap))

throw new RuntimeException("Will not happen");

}

}