Null pointer exception while displaying captcha

Question

package org.entity;

import java.io.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import nl.captcha.Captcha;

import com.opensymphony.xwork2.ActionSupport;

public class RegistrationAction extends ActionSupport {
    BloodBank register;
    private Map<String, Object> session;

    public BloodBank getRegister() {
        return register;
    }

    public void setRegister(BloodBank register) {
        this.register = register;
    }

    public Map<String, Object> getSession() {
        return session;
    }

    public void setSession(Map<String, Object> session) {
        this.session = session;
    }

    @Override
    public String execute() throws Exception {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/foryou", "root", "siddheshkk");
            System.out.println("Driver Loaded");
            PreparedStatement st = con
                    .prepareStatement("insert into bbinfo(code,name,address,city,district,contactno,password,aname,email) "
                            + "values(?,?,?,?,?,?,?,?,?)");
            st.setString(1, register.getCode());
            st.setString(2, register.getBbname());
            st.setString(3, register.getAddress());
            st.setString(4, register.getCity());
            st.setString(5, register.getDistrict());
            st.setString(6, register.getNumber());
            st.setString(7, register.getPassword());
            st.setString(8, register.getAname());
            st.setString(9, register.getEmail());
            st.executeUpdate();
            st.close();

            PreparedStatement st1 = con
                    .prepareStatement("insert into stockinfo(name,city,address,contact,email,code,apositive,anegative,bpositive,bnegative,abpositive,abnegative,opositive,onegative)"
                            + "values(?,?,?,?,?,?,'0','0','0','0','0','0','0','0')");
            st1.setString(1, register.getBbname());
            st1.setString(2, register.getCity());
            st1.setString(3, register.getAddress());
            st1.setString(4, register.getNumber());
            st1.setString(5, register.getEmail());
            st1.setString(6, register.getCode());
            st1.executeUpdate();
            st1.close();
            con.close();
            System.out.println("done");

        } catch (Exception e) {
            e.printStackTrace();
        }
        return "success";
    }

    @Override
    public void validate() {
        super.validate();
        if (register.getCode().length() < 1 | register.getCode().equals("")) {
            addFieldError("register.code", "Mandatory Field.");
        }
        if (register.getBbname().equals("") | register.getBbname().length() < 1) {
            addFieldError("register.bbname", "Invalid Name");
        }
        if (register.getAddress().equals("")) {

            addFieldError("register.address", "Invalid Address");
        }
        if (register.getCity().equals("")) {
            addFieldError("register.city", "Invalid City");

        }
        if (register.getDistrict().equals("")) {
            addFieldError("register.district", "Invalid District");

        }
        if (register.getPassword().length() > 8
                | register.getPassword().equals("")) {
            addFieldError("register.password", "Please Enter a valid Password");
        }
        if (!(register.getConfirm().equals(register.getPassword()))) {
            addFieldError("register.confirm", "Password doesnt match");
        }
        if (register.getConfirm().isEmpty()) {
            addFieldError("register.confirm", "Please enter confirmed password");
        }
        if (register.getAname().equals("")) {
            addFieldError("register.aname", "Please enter your name");
            ;
        }
        if (register.getEmail().equals("")) {
            addFieldError("register.email", "Invalid Email Id");
        } else {
            String expression = "^[\\w\\-]([\\.\\w])+[\\w]+@([\\w\\-]+\\.)+[A-Z]{2,4}$";
            CharSequence inputStr = register.getEmail();
            Pattern pattern = Pattern.compile(expression,
                    Pattern.CASE_INSENSITIVE);
            Matcher matcher = pattern.matcher(inputStr);
            if (!matcher.matches())
                addFieldError("register.email", "Invalid email address");
        }
        Captcha captcha = (Captcha) session.get(Captcha.NAME);
        if (!(captcha.isCorrect(register.getCaptchaAnswer()))) {
            addFieldError("register.captchaAnswer", "incorrect captcha");
        }

    }
}

Here is my action class whenever i am trying to register its giving null pointer exception at line 123.

That's from where Captcha code starts in validate method here:

        Captcha captcha = (Captcha) session.get(Captcha.NAME);
        if (!(captcha.isCorrect(register.getCaptchaAnswer()))) {
            addFieldError("register.captchaAnswer", "incorrect captcha");
        }

    }
}

I am attaching my error file as well. Below is my jsp file.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="/struts-tags" prefix="s"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Blood Bank Section</title>
<style type="text/css">
body {
    color: black;
    font-family: sans-serif;
    font: italic;
}

h1 {
    color: black;
    background-color: black;
    font: bold;
    outline-color: gray;
    font-style: oblique;
    font-family: cursive;
}

h3 {
    color: yellow;
    background-color: olive;
}

.loginDialog {
    position: fixed;
    font-family: Arial, Helvetica, sans-serif;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: rgba(0, 0, 0, 0.8);
    z-index: 0;
    opacity: 0;
    -webkit-transition: opacity 400ms ease-in;
    -moz-transition: opacity 400ms ease-in;
    transition: opacity 400ms ease-in;
    pointer-events: none;
}

.loginDialog>div {
    width: 400px;
    position: relative;
    margin: 10% auto;
    padding: 5px 20px 13px 20px;
    border-radius: 10px;
    background: #fff;
    background: -moz-linear-gradient(#fff, #999);
    background: -webkit-linear-gradient(#fff, #999);
    background: -o-linear-gradient(#fff, #999);
}

.close {
    background: #606061;
    color: #FFFFFF;
    line-height: 25px;
    position: absolute;
    right: -12px;
    text-align: center;
    top: -10px;
    width: 24px;
    text-decoration: none;
    font-weight: bold;
    -webkit-border-radius: 12px;
    -moz-border-radius: 12px;
    border-radius: 12px;
    -moz-box-shadow: 1px 1px 3px #000;
    -webkit-box-shadow: 1px 1px 3px #000;
    box-shadow: 1px 1px 3px #000;
}

.close:hover {
    background: #00d9ff;
}

form p {
    text-align: center;
}

form p input {
    font-size: 16px;
    height: 28px;
}

.loginDialog:target {
    opacity: 1;
    pointer-events: auto;
}
</style>
</head>
<body>
    <a href="welcome.jsp">Home</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href="Admin.jsp">Admin Panel</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href="BloodBankSection.jsp">Blood Bank Section</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href="#login">Blood Bank Login</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href=DonorSection.jsp>Donor Section</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href="Feedback.jsp">Feedback</a>&nbsp&nbsp&nbsp&nbsp&nbsp
    <a href="aboutus.jsp">About Us</a>
    </br>
    </br>
    <h5>Please Register to sign in.</h5>
    <h3 align="left">Registration Details:</h3>
    <h3 align="left">----------------------------</h3>
    <div align="left">
        <s:form action="registration" method="post"
            onsubmit="return validateForm()">
            <s:textfield label="Code " name="register.code" />
            <s:textfield label="Blood Bank Name " name="register.bbname" />
            <s:textfield label="Address " name="register.address" />
            <s:textfield label="City " name="register.city" />
            <s:textfield label="District " name="register.district" />
            <s:textfield label="Contact Number " name="register.number" />
            <s:textfield label="Email Id " name="register.email" />
            <s:password label="Password " name="register.password" />
            <s:password label="Confirm Password" name="register.confirm" />
            <s:textfield label="Enter your name " name="register.aname" />
            <tr>
                <td></td>
                <td><img src="<c:url value="simpleCaptcha.png" />" /></td>
            </tr>
            <s:textfield label="Enter code" key="register.captchaAnswer" size="30" />
            <s:submit value="Register" />
        </s:form>

        <h5 align="left">Already a member?? then sign in.</h5>
    </div>

    <div id="login" class="loginDialog">
        <div>
            <a href="#close" title="close">X</a>
            <h2>Login to web App</h2>
            <form action="LoginAction" method="post">
                <p>
                    <input type="text" name="login.code" placeholder="Registered Code">
                </p>
                <p>
                    <input type="password" name="login.password" placeholder="Password">
                </p>
                <p class="remember_me">
                    <label> <input type="checkbox" name="remember_me">Remember
                        me on this computer
                    </label>
                </p>
                <p>
                    <a href="ForgotPassword.jsp">Forgot Password ?</a>
                </p>
                <p class="submit">
                    <input type="submit" value="login">
                </p>
            </form>
        </div>
    </div>
</body>
</html>

Answer 1

Please,check if you have added the entry for register.captchaAnswer in your probably I18N properties file.

   <s:textfield label="Enter code" key="register.captchaAnswer" size="30" />