public static String getParameter(ServletRequest request, String name) {
    String s = request.getParameter(name);
    if (s == null) {
      return null;
    }
    s = s.trim();
    return s.length() == 0? null: s;
  }
public static String getParameter ( ServletRequest request , String name ) { String s = request . getParameter ( name ) ; if ( s == null ) { return null ; } s = s . trim ( ) ; return s . length ( ) == 0 ? null : s ; }
Get a parameter from a ServletRequest.
Return null if the parameter contains only white spaces.