java parser benchmark

Scan.java

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.EOFException;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.PrintStream;
import java.io.RandomAccessFile;
import java.nio.IntBuffer;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Random;
import java.util.Scanner;

public class Scan {

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

		PrintStream textOut = new PrintStream("data.txt");
		DataOutputStream binOut = new DataOutputStream(new FileOutputStream("data.bin"));
		Random r = new Random(0l);

		for (int i = 0; i < 1000000; i++) {
			int n = r.nextInt();
			textOut.print(n);
			textOut.print('\n');
			binOut.writeInt(n);
		}
		textOut.close();
		binOut.close();

		{
			long start = System.currentTimeMillis();
			BufferedReader reader = new BufferedReader(new FileReader("data.txt"));

			int sum = 0;
			while (true) {
				String line = reader.readLine();
				if (line == null)
					break;
				sum += Integer.parseInt(line);
			}
			reader.close();
			System.out.println("BufferedReader: " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

		{
			long start = System.currentTimeMillis();
			Scanner s = new Scanner(new FileReader("data.txt"));
			int sum = 0;
			while (s.hasNext()) {
				sum += s.nextInt();
			}
			s.close();
			System.out.println("Scanner: " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

		{
			long start = System.currentTimeMillis();
			FileChannel channel = FileChannel.open(Paths.get("data.txt"), StandardOpenOption.READ);
			Scanner s = new Scanner(channel);
			int sum = 0;
			while (s.hasNext()) {
				sum += s.nextInt();
			}
			channel.close();
			System.out.println("Scanner(FileChannel): " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}
		
		{
			long start = System.currentTimeMillis();
			FileChannel channel = FileChannel.open(Paths.get("data.txt"), StandardOpenOption.READ);
			MappedByteBuffer buffer = channel.map(MapMode.READ_ONLY, 0, channel.size());

			int sum = 0;
			int n = 0;
			int sign = 1;
			for (int i = 0; i < buffer.limit(); i++) {
				switch (buffer.get(i)) {
				case '-':
					sign = -1;
					break;
				case '\n':
					sum += sign * n;
					n = 0;
					sign = 1;
					break;
				default:
					n = n * 10 + buffer.get(i) - '0';
					break;
				}
			}

			channel.close();
			System.out.println("MappedByteBuffer: " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

		{
			long start = System.currentTimeMillis();
			FileChannel channel = FileChannel.open(Paths.get("data.bin"), StandardOpenOption.READ);
			MappedByteBuffer buffer = channel.map(MapMode.READ_ONLY, 0, channel.size());
			IntBuffer intBuffer = buffer.asIntBuffer();
			int sum = 0;
			for (int i = 0; i < intBuffer.limit(); i++) {
				sum += intBuffer.get(i);
			}
			channel.close();
			System.out.println("IntBuffer: " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

		{
			long start = System.currentTimeMillis();
			RandomAccessFile input = new RandomAccessFile("data.bin", "r");
			int sum = 0;
			int length = (int) (input.length() / 4);
			for (int i = 0; i < length; i++) {
				sum += input.readInt();
			}

			input.close();
			System.out.println("RandomAccessFile: " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

		{
			long start = System.currentTimeMillis();
			DataInputStream input = new DataInputStream(new BufferedInputStream(new FileInputStream("data.bin")));
			int sum = 0;

			try {
				while (true) {
					sum += input.readInt();
				}
			} catch (EOFException e) {
			}

			input.close();
			System.out.println("DataInputStream(BufferedInputStream): " + sum + " " + (System.currentTimeMillis() - start) + "ms");
		}

	}
}