Java Made Easy

in this post we will learn how to call validate class method and how to send values from servlet
to that method and how to get errors to servlet and how to display errors in jsp page

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import model.UserBean;
import validation.ValidateForm;

/**
 *
 * @author Jagadeesh
 */

public class ControllerServlet extends HttpServlet {
   
   //declare values to get form values from jsp page
           String userName;
           String dateOfBirth;
           String email;
           String phoneNo;
           String action;

           UserBean bean = new UserBean();
           ValidateForm validateform = new ValidateForm();
           
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        try {
           //get the values from jsp page
            userName = request.getParameter("userName");
            dateOfBirth = request.getParameter("dateOfBirth");
            email = request.getParameter("email");
            phoneNo = request.getParameter("phoneNo");
            action = request.getParameter("action");
           if(action.equals("submit"))
           {
          //set values to bean.For this call below method
            setValuesToBean();

          //check all form values are valid or not. send bean object 
            UserBean checkedbean = validateform.validateData(bean);
            if(!checkedbean.getIsValid())
            {
                //if data is invalid.set bean object in request and pass that request to
                //insertupdate.jsp using forward
                checkedbean.setAction("submit");
                request.setAttribute("error",checkedbean);
                RequestDispatcher rd = request.getRequestDispatcher("insertupdate.jsp");
                rd.forward(request, response);
                //now display errors in that jsp page
            }
           }
        } 
        catch(Exception e)
        {
            out.println(e);
        }
        finally {
            out.close();
        }
    }
    //this method is used to setvalues to bean
   public void setValuesToBean()
   {
       bean.setUserName(userName);
       bean.setDateOfBirth(dateOfBirth);
       bean.setEmail(email);
       bean.setPhoneNo(phoneNo);
       
   }

in this servlet we validate all values by calling validatedata() and if it is invalid we forward
errors to insertupdate.jsp page . we set that bean object in request and we forward page using RequestDispatcher.

in next post we will learn how to display errors in jsp page

in this post we will create methods for validate form values and set errors to bean if those values are invalid.
now create methods.

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package validation;
import model.UserBean;
/**
 *
 * @author Jagadeesh
 */
public class ValidateForm {

        
    UserBean validBean = new UserBean();
    public UserBean validateData(UserBean ubean)
    {

        //if given username value is not valid then seterror
        // message and set empty value to input field
        if(ubean.getUserName().length()==0)
        {
            validBean.setUserNameError("please enter valid name");
            validBean.setIsValid(false);
            validBean.setUserName("");
        }
        else
        if(!ubean.getUserName().matches("[a-zA-Z]*"))
        {
            validBean.setUserNameError("please enter valid name");
            validBean.setIsValid(false);
            validBean.setUserName("");
   
        }
        //if given username value is valid then seterror message to
        // empty and set value to bean
        else
        {
            validBean.setUserNameError("");
            validBean.setIsValid(true);
            validBean.setUserName(ubean.getUserName());
        }
        

        //if given username value is not valid then seterror message
       // and set empty value to input field
        if(!ubean.getDateOfBirth().matches("\\d{1,2}-\\d{1,2}-\\d{4}"))
        {
            validBean.setDateOfBirthError("please enter valid date");
            validBean.setIsValid(false);
            validBean.setDateOfBirth("");
   
        }
        //if given username value is valid then seterror message
        // to empty and set value to bean
        else
        {
            validBean.setDateOfBirthError("");
            validBean.setIsValid(true);
            validBean.setDateOfBirth(ubean.getDateOfBirth());
        }


        //if given username value is not valid then seterror message 
        //and set empty value to input field

        if(!ubean.getEmail().matches("^[\\w-_\\.+]*[\\w-_\\.]\\@([\\w]+\\.)+[\\w]+[\\w]$"))
        {
            validBean.setEmailError("please enter valid email");
            validBean.setIsValid(false);
            validBean.setEmail("");
        }
        //if given username value is valid then seterror message
        //to empty and set value to bean
        else
        {
            validBean.setEmailError("");
            validBean.setIsValid(true);
            validBean.setEmail(ubean.getEmail());
        }
  
        //if given username value is not valid then seterror message
        // and set empty value to input field
        if(!ubean.getPhoneNo().matches("\\d{10}"))
        {
            validBean.setPhoneNoError("please enter valid phoneno");
            validBean.setIsValid(false);
            validBean.setPhoneNo("");
        }
        //if given username value is valid then seterror message to 
        // empty and set value to bean
        else
        {
            validBean.setPhoneNoError("");
            validBean.setIsValid(true);
            validBean.setPhoneNo(ubean.getPhoneNo());
        }
        return validBean;
    }
}

In this post we will learn how to create a package in netbeans and how to create a class in that pakage.
Right click on source packages and select package


Enter package name(model in this example) and click next
now create a bean class with in this package. for this select that package and right click and select create and select class. and now enter name of that class.In this example that class name is UserBean. and click finish


then netbeans creates a class with default structure.

package model;

/**
 *
 * @author Jagadeesh
 */
public class UserBean {

}

now insert setter methods and getter methods in that been.Simple way to create setter methods and getter methods.
1. declare variables
2. select all variables and right click and click on insert code. select setter methods and getter methods and ok

package model;
package model;

/**
  * @author Jagadeesh
 */
public class UserBean {

   private String userName ;
   private String dateOfBirth ;
   private String email ;
   private String phoneNo ;

   //for validation error messages

   private String userNameError;
   private String dateOfBirthError;
   private String emailError;
   private String phoneNoError;
   private boolean isValid;

  //this is for action means edit or submit or delete or update
   private String action;
   //construtor.it is invoked when we run jsp page.
   //so first time no values will display in jsp page
   public UserBean()  
    {
       userName ="";
       dateOfBirth ="";
       email="";
       phoneNo="";
       
       userNameError="";
       dateOfBirthError="";
       emailError="";
       phoneNoError="";

       action = "submit";
    }

    public String getDateOfBirth() {
        return dateOfBirth;
    }

    public void setDateOfBirth(String dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhoneNo() {
        return phoneNo;
    }

    public void setPhoneNo(String phoneNo) {
        this.phoneNo = phoneNo;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    //setter and getter methods for errors
    
    public String getUserNameError() {
         return userNameError;
    }

    public void setUserNameError(String userNameError) {
        this.userNameError = userNameError;
    }
    public String getDateOfBirthError() {
         return dateOfBirthError;
    }

    public void setDateOfBirthError(String dateOfBirthError) {
        this.dateOfBirthError = dateOfBirthError;
    }

    public String getEmailError() {
         return emailError;
    }

    public void setEmailError(String emailError) {
        this.emailError = emailError;
    }

    public String getPhoneNoError() {
        return phoneNoError;
    }

    public void setPhoneNoError(String phoneNoError) {
        this.phoneNoError = phoneNoError;
    }

    public boolean getIsValid() {
        return isValid;
    }
    public void setIsValid(boolean isValid) {
        this.isValid = isValid;
    }

    public String getAction() {
        return action;
    }
    public void setAction(String action) {
        this.action = action;
    }

 }

in next post we will create a class for validate form