import java.io.PrintWriter;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class SqrtServlet extends HttpServlet {
//serial version UID to be able to identify the version of the source code
private static final long serialVersionUID = 0L;
public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
//Pick up PrintWriter output stream for response
PrintWriter out = response.getWriter();
//Generate standard HTML header etc
out.println(" Square roots ");
out.println("");
//Pick up name=value bindings for data from the form
String data = request.getParameter("number");
double value = 0.0;
//Does the String represent a number?
try {value = Double.parseDouble(data);}
catch(Exception e){
//String is not a number. Return message and close HTML document
out.println("Hey... I need NUMERIC data!");
out.println("");
return;
}
//Value must be non-negative for the sqrt-operation
if(value<0.0){
out.println("You are living in an imaginary world!");
out.println("