Mapping an entire file into memory for reading : Input Output Stream « File Input Output « Java






Mapping an entire file into memory for reading


// : c12:MappedFile.java
// Mapping an entire file into memory for reading.
// {Args: MappedFile.java}
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.

import java.io.File;
import java.io.FileInputStream;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;

public class MappedFile {
  public static void main(String[] args) throws Exception {
    if (args.length != 1) {
      System.out.println("argument: sourcefile");
      System.exit(1);
    }
    long length = new File(args[0]).length();
    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++));
  }
} ///:~


           
       








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