randomcreator.java

mpi实现并行排序算法

import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Random;

/**
 * This is a random number generator
 *
 * @author vicent
 * @author Mingliang Liu
 */
public class RandomCreator {
	public static Random random = new Random(System.currentTimeMillis());

	public static void main(String args[]) throws IOException {
		int mode = 1;

		if (args.length < 2)
			mode = 1;
		else if (args.length == 2)
			mode = 2;
		else if (args.length == 3 && "-b".equalsIgnoreCase(args[2]))
			mode = 3;

		if (mode == 1) {
			System.out.print("usage:RandomCreator file number [-b]");
			return;
			
		} else if (mode == 2) {
			File file = new File(args[0]);
			int number = Integer.parseInt(args[1]);
			if (number <= 0) {
				System.out.println("Number less then zero!");
				return;
			} else
				System.out.println("Creating " + number + " random number...");

			FileWriter writer = new FileWriter(file);

			writer.write(String.valueOf(number));
			for (int i = 0; i < number; i++) {
				writer.write(";");
				writer.write(String.valueOf(random.nextInt(10000)));
			}
			writer.write(";");

			writer.close();
			System.out.println("Finished.");
			
		} else if (mode==3){
			File file = new File(args[0]);
			int number = Integer.parseInt(args[1]);
			if (number <= 0) {
				System.out.println("Number less then zero!");
				return;
			} else
				System.out.println("Creating " + number + " random number with binary mode...");

			FileOutputStream binOut = new FileOutputStream(file);
			FileWriter writer = new FileWriter(file);
			
			writer.write(String.valueOf(number));
			binOut.write(intToByteArray(number));
			for (int i = 0; i < number; i++) {
				writer.write(";");
				int n = random.nextInt(10000);
				writer.write(String.valueOf(n));
				binOut.write(intToByteArray(n));
			}
			writer.write(";");
			
			writer.close();
			binOut.close();
			System.out.println("Finished.");
		}
	}
	
	public static byte[] intToByteArray(int i) {
		byte[] byteArrayData = new byte[4];

		byteArrayData[0] = (byte) (0xff & i);
		byteArrayData[1] = (byte) (0xff & (i >> 8));
		byteArrayData[2] = (byte) (0xff & (i >> 16));
		byteArrayData[3] = (byte) (0xff & (i >> 24));

		return byteArrayData;
	}

}