Random CSS background-image generated with JSP

random-css-background-image.jsp

<%
	File imageDirectory = new File("./images");
	String images[] = imageDirectory.list();

	if(images != null){
		int imageNumber = 0;
		double randomNumber = Math.random();
	
		int random2Digits = (int)(randomNumber * 100);
		for(int i = 0; i < random2Digits; i++){
			imageNumber = i % images.length;
		}
		
		String imageName = images[imageNumber];
		int red = 0;
		int green = 0;
		int blue = 0;
		
		if(imageName.length() > 13){
			int lastDot = imageName.lastIndexOf(".");
			String redString = imageName.substring(lastDot - 9, lastDot - 6);
			String greenString = imageName.substring(lastDot - 6, lastDot - 3);
			String blueString = imageName.substring(lastDot - 3, lastDot);
			try{
				red = Integer.parseInt(redString);
			}
			catch(Exception e){
			}
			try{
				green = Integer.parseInt(greenString);
			}
			catch(Exception e){
			}
			try{
				blue = Integer.parseInt(blueString);
			}
			catch(Exception e){
			}
		}	

	out.print("html{background: url(images/"+images[imageNumber]+");}");
	
	}
%>