computerpi.java

可以让初学者有一个感性的认识

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class ComputerPI extends HttpServlet
{
	double sum=0,i=1,j=1;
	int number=0;

	public void init(ServletConfig config) throws ServletException
	{
		super.init(config);
	}

	public void service(HttpServletRequest request,HttpServletResponse response) throws IOException
	{
		PrintWriter out=response.getWriter();
		response.setContentType("text/plain");
		number++;
		sum=sum+i/j;
		j=j+2;
		i=-i;
		out.println("you are "+number+"th people coming to here.");
		out.println("Now PI="+4*sum);
	}
}