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

public class RandPPM
 {
  
  static Random rng = new Random();
  
  public static Pixel genRandPixel() {
    Pixel p = new Pixel(); // RGB=0,0,0
    // note that nextInt(256) gives us 0..255
    p.r = rng.nextInt(256); 
    p.g = rng.nextInt(256);
    p.b = rng.nextInt(256);
    return p;
  }// genRandPixel()
  
  public static void main(String[] args) throws IOException {
    
    int xRes=256, yRes=256;
    
    
    File f = new File("C:\\temp\\rand.ppm");
    FileOutputStream fout = new FileOutputStream(f);
    PrintStream out = new PrintStream(fout);
    
    // header
    out.println("P3\r\n" + xRes + " " + yRes + "\r\n255\r\n"); // P2 xres yres maxval
    
    // pixel data: RGB triplets, each value 0..255
    for(int y=0;y<yRes;y++) {
      for(int x=0;x<xRes;x++) {
        
        Pixel pxl = genRandPixel();
        out.println(pxl.r + " " + pxl.g + " " + pxl.b);
        
      }// next x
    }// next y
    
    // done, close
    out.close();
  }// main()
  
  // static inner class 
  private static class Pixel {
    int r=0, g=0, b=0;
  }// class Pixel
  
}// class RandPPM