15
Netprog 2002  -  Servlets
Circle Servlet
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
public class circle extends HttpServlet {
  public void doGet(HttpServletRequest request,
HttpServletResponse response)
      throws ServletException, IOException {
response.setContentType("text/html");   
PrintWriter out = response.getWriter();
    out.println(   "<BODY><H1 ALIGN=CENTER> Circle Info </H1>\n");
try{
  String sdiam = request.getParameter("diameter");
  double diam = Double.parseDouble(sdiam);
  out.println("<BR><H3>Diam:</H3>" + diam +
"<BR><H3>Area:</H3>" + diam/2.0 * diam/2.0 * 3.14159 +
"<BR><H3>Perimeter:</H3>" + 2.0 * diam/2.0 * 3.14159);
 } catch ( NumberFormatException e ){
  out.println("Please enter a valid number");
}
    out.println("</BODY></HTML>");
  }
Attach a PrintWriter to Response Object
Specify HTML output.
Subclass
HttpServlet.