MappedReader.java Source code

Introduction

Here is the source code for MappedReader.java

Source

// : 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++));
    }
} ///:~