jsp - how do i solve the double method while string in java with servlet -

package com.dev.web.controller;  import java.io.ioexception; import java.text.parseexception; import java.text.simpledateformat; import java.util.date; import javax.servlet.requestdispatcher; import javax.servlet.servletexception; import javax.servlet.http.httpservlet; import javax.servlet.http.httpservletrequest; import javax.servlet.http.httpservletresponse; import com.dev.web.dao.userdao; import com.dev.web.model.user;  public class usercontroll extends httpservlet {     private static final long serialversionuid = 1l;     private static string insert_or_edit = "/user.jsp";     private static string list_user = "/listemp.jsp";     private userdao dao;      public usercontroll() {         super();       userdao dao = new userdao();     }      protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {         string forward="";         string action = request.getparameter("action");          if (action.equalsignorecase("delete")){             int employee_id= integer.parseint(request.getparameter("employee_id"));             dao.deleteuser(employee_id);             forward = list_user;             request.setattribute("users", dao.getallusers());             } else if (action.equalsignorecase("edit")){             forward = insert_or_edit;             int employee_id = integer.parseint(request.getparameter("empid"));             user user = dao.getuserbyid(employee_id);             request.setattribute("user", user);         } else if (action.equalsignorecase("listuser")){             forward = list_user;             request.setattribute("employee", dao.getallusers());         } else {             forward = insert_or_edit;         }          requestdispatcher view = request.getrequestdispatcher(forward);         view.forward(request, response);     }      protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {         user user = new user();         user.setemployee_name(request.getparameter("empname"));         user.setsalary(request.getparameter("empsalary"));// here error..i declared salary double         try {             date dob = new simpledateformat("mm/dd/yyyy").parse(request.getparameter("empdob"));             user.setdob(dob);         } catch (parseexception e) {             e.printstacktrace();         }         user.setactive(request.getparameter("empactive"));// here error.. declared active boolean         string empid = request.getparameter("empid");         if(empid == null || empid.isempty())         {             dao.adduser(user);         }         else         {             user.setemployee_id(integer.par`enter code here`seint(empid));             dao.updateuser(user);         }         requestdispatcher view = request.getrequestdispatcher(list_user);         request.setattribute("users", dao.getallusers());         view.forward(request, response);     } } 

the getparameter() method of httpservletrequest inherited servletrequest. api docs can see method returns string. need parse boolean or double string, example

double.parsedouble(request.getparameter("empsalary"));