Validate INPUT TEXT

Question

Hi there,
Anybody can help me,just I have a page with 3 numeric field and I need to validate these field, the idea is accept only numeric input, how can I do this?

Answer 1

Something like this. This code assumes an Integer .
boolean validation=true;
int num=0;
String val=request.getParameter("parameterName");
try {
  if (val!=null){
         num=Integer.parseInt(val); //NumberFormatException thrown here if not a number
  } else {
        validation=false;
catch (NumberFormatException nfe){
validation=false;
}