// : c12:MappedReader.java
// What happens when the entire file
// isn't in your mapping region?
// {ThrowsException}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.io.FileInputStream;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
public class MappedReader {
private static final int LENGTH = 100; // Small
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("argument: sourcefile");
System.exit(1);
}
MappedByteBuffer in = new FileInputStream(args[0]).getChannel().map(
FileChannel.MapMode.READ_ONLY, 0, LENGTH);
int i = 0;
while (i < LENGTH)
System.out.print((char) in.get(i++));
System.out.println((char) in.get(i++));
}
} ///:~