Java 3

Week 2

top-nav

Find Bootstrap header examples on this page.
In the "WEB-INF/" folder, create a new file called top-nav.jsp. Add this HTML code.

 <div class="container">
    <nav class="navbar navbar-expand-lg bg-body-tertiary rounded" aria-label="Eleventh navbar example">
      <div class="container-fluid">
        <a class="navbar-brand" href="#">Navbar</a>
        <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarsExample09" aria-controls="navbarsExample09" aria-expanded="false" aria-label="Toggle navigation">
          <span class="navbar-toggler-icon"></span>
        </button>

        <div class="collapse navbar-collapse" id="navbarsExample09">
          <ul class="navbar-nav me-auto mb-2 mb-lg-0">
            <li class="nav-item">
              <a class="nav-link active" aria-current="page" href="#">Home</a>
            </li>
            <li class="nav-item">
              <a class="nav-link" href="#">Link</a>
            </li>
            <li class="nav-item">
              <a class="nav-link disabled" aria-disabled="true">Disabled</a>
            </li>
            <li class="nav-item dropdown">
              <a class="nav-link dropdown-toggle" href="#" data-bs-toggle="dropdown" aria-expanded="false">Dropdown</a>
              <ul class="dropdown-menu">
                <li><a class="dropdown-item" href="#">Action</a></li>
                <li><a class="dropdown-item" href="#">Another action</a></li>
                <li><a class="dropdown-item" href="#">Something else here</a></li>
              </ul>
            </li>
          </ul>
          <form role="search">
            <input class="form-control" type="search" placeholder="Search" aria-label="Search">
          </form>
          <div class="d-lg-flex col-lg-3 justify-content-lg-end">
            <a href="#" class="btn btn-outline-primary me-2">Login</a>
            <a href="#" class="btn btn-primary">Sign-up</a>
          </div>
        </div>
      </div>
    </nav>
</div>

bottom-nav

Find Bootstrap footer examples on this page.
In the "WEB-INF/" folder, create a new file called bottom-nav.jsp. Add this HTML code.

<div class="container">
  <footer class="py-5">
    <div class="row">
      <div class="col-6 col-md-2 mb-3">
        <h5>Section</h5>
        <ul class="nav flex-column">
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Home</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Features</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Pricing</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">FAQs</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">About</a></li>
        </ul>
      </div>

      <div class="col-6 col-md-2 mb-3">
        <h5>Section</h5>
        <ul class="nav flex-column">
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Home</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Features</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Pricing</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">FAQs</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">About</a></li>
        </ul>
      </div>

      <div class="col-6 col-md-2 mb-3">
        <h5>Section</h5>
        <ul class="nav flex-column">
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Home</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Features</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">Pricing</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">FAQs</a></li>
          <li class="nav-item mb-2"><a href="#" class="nav-link p-0 text-body-secondary">About</a></li>
        </ul>
      </div>

      <div class="col-md-5 offset-md-1 mb-3">
        <form>
          <h5>Subscribe to our newsletter</h5>
          <p>Monthly digest of what's new and exciting from us.</p>
          <div class="d-flex flex-column flex-sm-row w-100 gap-2">
            <label for="newsletter1" class="visually-hidden">Email address</label>
            <input id="newsletter1" type="text" class="form-control" placeholder="Email address">
            <button class="btn btn-primary" type="button">Subscribe</button>
          </div>
        </form>
      </div>
    </div>

    <div class="d-flex flex-column flex-sm-row justify-content-between py-4 my-4 border-top">
      <p>&copy; 2024 Company, Inc. All rights reserved.</p>
      <ul class="list-unstyled d-flex">
        <li class="ms-3"><a class="link-body-emphasis" href="#"><svg class="bi" width="24" height="24"><use xlink:href="#twitter"/></svg></a></li>
        <li class="ms-3"><a class="link-body-emphasis" href="#"><svg class="bi" width="24" height="24"><use xlink:href="#instagram"/></svg></a></li>
        <li class="ms-3"><a class="link-body-emphasis" href="#"><svg class="bi" width="24" height="24"><use xlink:href="#facebook"/></svg></a></li>
      </ul>
    </div>
  </footer>
</div>

top.jsp

In the "WEB-INF/" folder, create a new file called top.jsp.
- This file will be used to define tag library declarations, the DOCTYPE tag, html tag, head tags, meta tags, title tag, link tags, and a top-nav include tag to be available to all JSPs.
Add tag library declarations (lines 2-4) at the beginning of top.jsp
A pageTitle attribute will eventually be set to each servlet.
Add Bootstrap and Bootstrap Icon CSS files.
- You may add additional stylesheets to this file later.

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="jakarta.tags.core" %>
<%@ taglib prefix="fmt" uri="jakarta.tags.fmt" %>
<%@ taglib prefix="fn" uri="jakarta.tags.functions" %>
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>${pageTitle}</title>
<link
	href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css"
    rel="stylesheet"
    integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH"
    crossorigin="anonymous">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/font/bootstrap-icons.min.css">
</head>
<body>
<%@ include file="/WEB-INF/top-nav.jsp" %>

taglib directives

The first directive states that all JSPs will contain HTML.
The second directive will activate the core (c) JSTL group.
- Core tags provide logic and control flow support, URL management, and more.
The third directive tag will activate the formatting (fmt) JSTL group.
- Formatting tags are used to format and display text, date/time, and numbers for internationalized Websites.
The fourth directive tag will activate the functions (fn) JSTL group.
- Function tags are commonly used for string manipulation.
  We will discuss the fmt and fn JSTL libraries later.
We may add custom taglib directives later.

bottom.jsp

In the "WEB-INF/" folder, create a new file called bottom.jsp.
- This file will be used to define script tags, and the closing body and html tags to be available to all JSPs.
Add Bootstrap and jQuery JavaScript files.
- You may add additional JavaScript script tags to this file later.
The integrity and crossorigin attributes are used for Subresource Integrity (SRI) checking. This allows browsers to ensure that resources hosted on third-party servers have not been tampered with. Use of SRI is recommended as a best-practice, whenever libraries are loaded from a third-party source. Read more.

<%@ include file="/WEB-INF/bottom-nav.jsp" %> 
<script 
  src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js"
  integrity="sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz"
  crossorigin="anonymous"></script>
<script
  src="https://code.jquery.com/jquery-3.7.1.min.js"
  integrity="sha256-/JqT3SQfawRcv/BIHPThkBvs0OEvtFFmqPF/lYI/Cxo="
  crossorigin="anonymous"></script>
</body>
</html>

Home Servlet

In your project's "controllers/" package, create a new servlet called "HomeServlet".
Add the following code.
Note the URL value of the servlet is just an empty string ("")

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("")
public class HomeServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setAttribute("pageTitle", "Home");
        req.getRequestDispatcher("WEB-INF/home.jsp").forward(req, resp);
    }
}

Including files

Delete the index.jsp file found in the webapp folder.
Including JSPs in other JSP saves you from repeating the same code on every JSP.
Create a home.jsp file inside the WEB-INF folder.
Replace the content of home.jsp with the top and bottom include directives.
The include directive requires a file attribute. The file will be included at compile time.

<%@ include file="/WEB-INF/top.jsp" %>

<%@ include file="/WEB-INF/bottom.jsp" %>

Home Page Content

Between the include taglib directives, add the main content from the Bootstrap Carousel demo page.
- Do not add the header or footer.

<main>

  <div id="myCarousel" class="carousel slide mb-6" data-bs-ride="carousel">
    <div class="carousel-indicators">
      <button type="button" data-bs-target="#myCarousel" data-bs-slide-to="0" class="active" aria-current="true" aria-label="Slide 1"></button>
      <button type="button" data-bs-target="#myCarousel" data-bs-slide-to="1" aria-label="Slide 2"></button>
      <button type="button" data-bs-target="#myCarousel" data-bs-slide-to="2" aria-label="Slide 3"></button>
    </div>
    <div class="carousel-inner">
      <div class="carousel-item active">
        <svg class="bd-placeholder-img" width="100%" height="100%" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" preserveAspectRatio="xMidYMid slice" focusable="false"><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <div class="container">
          <div class="carousel-caption text-start">
            <h1>Example headline.</h1>
            <p class="opacity-75">Some representative placeholder content for the first slide of the carousel.</p>
            <p><a class="btn btn-lg btn-primary" href="#">Sign up today</a></p>
          </div>
        </div>
      </div>
      <div class="carousel-item">
        <svg class="bd-placeholder-img" width="100%" height="100%" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" preserveAspectRatio="xMidYMid slice" focusable="false"><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <div class="container">
          <div class="carousel-caption">
            <h1>Another example headline.</h1>
            <p>Some representative placeholder content for the second slide of the carousel.</p>
            <p><a class="btn btn-lg btn-primary" href="#">Learn more</a></p>
          </div>
        </div>
      </div>
      <div class="carousel-item">
        <svg class="bd-placeholder-img" width="100%" height="100%" xmlns="http://www.w3.org/2000/svg" aria-hidden="true" preserveAspectRatio="xMidYMid slice" focusable="false"><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <div class="container">
          <div class="carousel-caption text-end">
            <h1>One more for good measure.</h1>
            <p>Some representative placeholder content for the third slide of this carousel.</p>
            <p><a class="btn btn-lg btn-primary" href="#">Browse gallery</a></p>
          </div>
        </div>
      </div>
    </div>
    <button class="carousel-control-prev" type="button" data-bs-target="#myCarousel" data-bs-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="visually-hidden">Previous</span>
    </button>
    <button class="carousel-control-next" type="button" data-bs-target="#myCarousel" data-bs-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="visually-hidden">Next</span>
    </button>
  </div>


  <!-- Marketing messaging and featurettes
  ================================================== -->
  <!-- Wrap the rest of the page in another container to center all the content. -->

  <div class="container marketing">

    <!-- Three columns of text below the carousel -->
    <div class="row">
      <div class="col-lg-4">
        <svg class="bd-placeholder-img rounded-circle" width="140" height="140" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <h2 class="fw-normal">Heading</h2>
        <p>Some representative placeholder content for the three columns of text below the carousel. This is the first column.</p>
        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
      </div><!-- /.col-lg-4 -->
      <div class="col-lg-4">
        <svg class="bd-placeholder-img rounded-circle" width="140" height="140" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <h2 class="fw-normal">Heading</h2>
        <p>Another exciting bit of representative placeholder content. This time, we've moved on to the second column.</p>
        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
      </div><!-- /.col-lg-4 -->
      <div class="col-lg-4">
        <svg class="bd-placeholder-img rounded-circle" width="140" height="140" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-color)"/></svg>
        <h2 class="fw-normal">Heading</h2>
        <p>And lastly this, the third column of representative placeholder content.</p>
        <p><a class="btn btn-secondary" href="#">View details &raquo;</a></p>
      </div><!-- /.col-lg-4 -->
    </div><!-- /.row -->


    <!-- START THE FEATURETTES -->

    <hr class="featurette-divider">

    <div class="row featurette">
      <div class="col-md-7">
        <h2 class="featurette-heading fw-normal lh-1">First featurette heading. <span class="text-body-secondary">It’ll blow your mind.</span></h2>
        <p class="lead">Some great placeholder content for the first featurette here. Imagine some exciting prose here.</p>
      </div>
      <div class="col-md-5">
        <svg class="bd-placeholder-img bd-placeholder-img-lg featurette-image img-fluid mx-auto" width="500" height="500" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder: 500x500" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-bg)"/><text x="50%" y="50%" fill="var(--bs-secondary-color)" dy=".3em">500x500</text></svg>
      </div>
    </div>

    <hr class="featurette-divider">

    <div class="row featurette">
      <div class="col-md-7 order-md-2">
        <h2 class="featurette-heading fw-normal lh-1">Oh yeah, it’s that good. <span class="text-body-secondary">See for yourself.</span></h2>
        <p class="lead">Another featurette? Of course. More placeholder content here to give you an idea of how this layout would work with some actual real-world content in place.</p>
      </div>
      <div class="col-md-5 order-md-1">
        <svg class="bd-placeholder-img bd-placeholder-img-lg featurette-image img-fluid mx-auto" width="500" height="500" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder: 500x500" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-bg)"/><text x="50%" y="50%" fill="var(--bs-secondary-color)" dy=".3em">500x500</text></svg>
      </div>
    </div>

    <hr class="featurette-divider">

    <div class="row featurette">
      <div class="col-md-7">
        <h2 class="featurette-heading fw-normal lh-1">And lastly, this one. <span class="text-body-secondary">Checkmate.</span></h2>
        <p class="lead">And yes, this is the last block of representative placeholder content. Again, not really intended to be actually read, simply here to give you a better view of what this would look like with some actual content. Your content.</p>
      </div>
      <div class="col-md-5">
        <svg class="bd-placeholder-img bd-placeholder-img-lg featurette-image img-fluid mx-auto" width="500" height="500" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Placeholder: 500x500" preserveAspectRatio="xMidYMid slice" focusable="false"><title>Placeholder</title><rect width="100%" height="100%" fill="var(--bs-secondary-bg)"/><text x="50%" y="50%" fill="var(--bs-secondary-color)" dy=".3em">500x500</text></svg>
      </div>
    </div>

    <hr class="featurette-divider">

    <!-- /END THE FEATURETTES -->

  </div><!-- /.container -->
</main>

Custom CSS

Create a webapp/styles/ folder. Create a styles.css file. Add the styles from the Bootstrap Carousel demo page.
Add a new link tag to the head section of top.jsp

.bd-placeholder-img {
  font-size: 1.125rem;
  text-anchor: middle;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
}

@media (min-width: 768px) {
  .bd-placeholder-img-lg {
    font-size: 3.5rem;
  }
}

Signup Servlet

Create a new servlet in the called Signup. Add this code.

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

import java.io.IOException;

@WebServlet("/signup")
public class Signup extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setAttribute("pageTitle", "Sign up for an account");
        req.getRequestDispatcher("WEB-INF/signup.jsp").forward(req, resp);
    }
}

Edit the Sign-up hyperlink in the top-nav.jsp file

<a href="signup" class="btn btn-primary">Sign-up</a>

Including files

Create a signup.jsp file inside the WEB-INF folder.
Replace the content of with the top and bottom include directives.

<%@ include file="/WEB-INF/top.jsp" %>

<%@ include file="/WEB-INF/bottom.jsp" %>

Signup Form

Between the include directives, add the sign-up form from the Bootstrap Heroes example page.

  <div class="container col-xl-10 col-xxl-8 px-4 py-5">
    <div class="row align-items-center g-lg-5 py-5">
      <div class="col-lg-7 text-center text-lg-start">
        <h1 class="display-4 fw-bold lh-1 text-body-emphasis mb-3">Vertically centered hero sign-up form</h1>
        <p class="col-lg-10 fs-4">Below is an example form built entirely with Bootstrap’s form controls. Each required form group has a validation state that can be triggered by attempting to submit the form without completing it.</p>
      </div>
      <div class="col-md-10 mx-auto col-lg-5">
        <form class="p-4 p-md-5 border rounded-3 bg-body-tertiary">
          <div class="form-floating mb-3">
            <input type="email" class="form-control" id="floatingInput" placeholder="name@example.com">
            <label for="floatingInput">Email address</label>
          </div>
          <div class="form-floating mb-3">
            <input type="password" class="form-control" id="floatingPassword" placeholder="Password">
            <label for="floatingPassword">Password</label>
          </div>
          <div class="checkbox mb-3">
            <label>
              <input type="checkbox" value="remember-me"> Remember me
            </label>
          </div>
          <button class="w-100 btn btn-lg btn-primary" type="submit">Sign up</button>
          <hr class="my-4">
          <small class="text-body-secondary">By clicking Sign up, you agree to the terms of use.</small>
        </form>
      </div>
    </div>
  </div>

Create a second password form input for the user to confirm their password.
Change the "Remember Me" text to "By clicking Sign up, you agree to the terms of use."
Change the old "By clicking Sign up..." text to "Already have an account? <a href="login">Log in here</a>".

Signup Form

Add form attributes.

<form method="post" action="signup">
Add name attributes to all form inputs that match the ids.

id="email" name="email" id="password1" name="password1" id="password2" name="password2"
Add a name and value attribute to the checkbox.name="termsOfUse" value="agree"

Signup Servlet doPost

Create a doPost method to get the parameters from the form submission.

String email = req.getParameter("email"); String password1 = req.getParameter("password1"); String password2 = req.getParameter("password2"); String[] termsOfService = req.getParameterValues("termsOfUse");
Immediately set those values as attributes. Note the ternary operator being used to set the termsOfUse attribute to "agree" only if the checkbox was checked.
req.setAttribute("email", email); req.setAttribute("password1", password1); req.setAttribute("password2" password2); req.setAttribute("termsOfUse", (termsOfUse != null && termsOfUse[0].equals("agree")) ? "agree" : "");

Signup Servlet processRequest

Create a processRequest method to the title and forward to the JSP.

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    processRequest(req, resp);
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
	// code omitted
    processRequest(req, resp);
}

Call this method at the end of the doGet and doPost methods.

protected void processRequest(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
	req.setAttribute("pageTitle", "Sign up for an account");
	req.getRequestDispatcher("WEB-INF/signup.jsp").forward(req, resp);
}

signup.jsp

Use expressions in value attributes to get attributes from the servlet
value="${email}" value="${password1}" value="${password2}"
Use a c:if tag inside in the checkbox input to re-select it.
<c:if test = "${termsOfUse == "agree"}">checked</c:if>
Run Tomcat. When you enter values and press submit, the values should remain in the form.

Validators

Add a method to the Validators class to validate a strong password.

public static boolean isStrongPassword(String password) {
	// Password requires 8 characters with at least 3 out 4 (uppercase letter, lowercase letter, number, special character ~`!@#$%^&*()_-+={}[]|\:;"'<>,.?/
	Pattern passwordPattern = Pattern.compile("^(?:(?=.*\\d)(?=.*[A-Z])(?=.*[a-z])|(?=.*\\d)(?=.*[^A-Za-z0-9])(?=.*[a-z])|(?=.*[^A-Za-z0-9])(?=.*[A-Z])(?=.*[a-z])|(?=.*\\d)(?=.*[A-Z])(?=.*[^A-Za-z0-9]))(?!.*(.)\\1{2,})[A-Za-z0-9~`!\\@#\\$%\\^&*()_\\-+={}\\[\\]\\|\\\\:;\"'<>,.?\\/]{8,128}$");
    Matcher matcher = pattern.matcher(passwordStr);
    return matcher.matches();
}

User class

Set the email and password only if they are valid.
The setPassword method will allow null values because we will set the password to null after it has been validated.

public void setEmail(String email) {
    if (!Validators.isValidEmail(email)) {
        throw new IllegalArgumentException("Invalid email address");
    }
    this.email = email;
}

public void setPassword(char[] password) {
	if (password != null) {
    	String passwordStr = String.valueOf(password);
    	if (!Validators.isStrongPassword(passwordStr)) {
        	throw new IllegalArgumentException("Password requires 8 characters with at least 3 out 4 (uppercase letter, lowercase letter, number, special character ~`!@#$%^&*()_-+={}[]|\\:;\"'<>,.?/");
    	}
    }
    this.password = password;
}

Signup Servlet

After setting the attributes in the doPost method, create a User object and validate all of the inputs.

User user = new User();
boolean errorFound = false;
try {
    user.setEmail(email);
} catch(IllegalArgumentException e) {
    req.setAttribute("emailError", e.getMessage());
    errorFound = true;
}
try {
    user.setPassword(password1.toCharArray());
} catch(IllegalArgumentException e) {
    req.setAttribute("password1Error", e.getMessage());
    errorFound = true;
}
if(password2.equals("")) {
    req.setAttribute("password2Error", "This input is required");
    errorFound = true;
}
if(!password1.equals(password2)) {
    req.setAttribute("password2Error", "Passwords don't match");
    errorFound = true;
}
if(termsOfService == null || !termsOfService[0].equals("agree")){
    req.setAttribute("termsOfUseError", "You must agree to our terms of use");
    errorFound = true;
}

signup.jsp

Use c:if tags with expressions to display error messages at the end of each input group.

<c:if test="${not empty emailError}"><div class="invalid-feedback">${emailError}</div></c:if>

<c:if test="${not empty password1Error }"><div class="invalid-feedback">${password1Error}</div></c:if>

<c:if test="${not empty password2Error }"><div class="invalid-feedback">${password2Error}</div></c:if>

<c:if test="${not empty termsOfUseError }"><div class="invalid-feedback">${termsOfUseError}</div></c:if>

signup.jsp

Use c:if tags with expressions in the form input class attributes.

class="form-control <c:if test="${not empty emailError}">is-invalid</c:if> "

class="form-control <c:if test="${not empty password1Error }">is-invalid</c:if> "

class="form-control <c:if test="${not empty password2Error }">is-invalid</c:if> "

class="form-check-input <c:if test="${not empty termsOfServiceError}">is-invalid</c:if>
Run the project and test invalid inputs.

Get User By Email

CREATE PROCEDURE sp_get_user(IN p_email VARCHAR(255))
BEGIN
    SELECT user_id, first_name, last_name, email, phone, password, language, status, privileges, created_at
    FROM user
    WHERE email = p_email;
END;

Step 1: Create/Update a stored procedure

Step 2: The User POJO does not need to be updated.

UserDAO

public static User get(String email) {
    User user = null;
    try (Connection connection = getConnection()) {
        if (connection != null) {
            try (CallableStatement statement = connection.prepareCall("{CALL sp_get_user(?)}")) {
                statement.setString(1, email);
                try (ResultSet resultSet = statement.executeQuery()) {
                    if (resultSet.next()) {
                        int id = resultSet.getInt("user_id");
                        String firstName = resultSet.getString("first_name");
                        String lastName = resultSet.getString("last_name");
                        String phone = resultSet.getString("phone");
                        char[] password = resultSet.getString("password").toCharArray();
                        String language = resultSet.getString("language");
                        String status = resultSet.getString("status");
                        String privileges = resultSet.getString("privileges");
                        Instant created_at = resultSet.getTimestamp("created_at").toInstant();
                        user = new User(id, firstName, lastName, email, phone, password, language, status, privileges, created_at);
                    }
                }
            }
        }
    } catch (SQLException e) {
        throw new RuntimeException(e);
    }
    return user;
}

Step 3: Implement a method to get a user by their email address.

Signup Servlet

if(UserDAO.get(email) != null) {
    req.setAttribute("emailError", "A user with that email already exists. <a href=\"signin\">Sign in</a> or <a href=\"reset-password\">reset the password</a>.");
    errorFound = true;
}

Step 4: Add an if statement that checks if the user already exists. Here we get the context-parameter set in the web.xml file. If we are on https we use the Azure URL. If we are on http we use localhost.

Run the program. Try to sign up a user with the email address already added to your database.

Update User

CREATE PROCEDURE sp_update_user(
    IN p_user_id int,
    IN p_first_name VARCHAR(255),
    IN p_last_name VARCHAR(255),
    IN p_email VARCHAR(255),
    IN p_phone VARCHAR(255),
    IN p_language VARCHAR(255),
    IN p_status VARCHAR(255),
    IN p_privileges VARCHAR(255)
)
BEGIN
    UPDATE user
    SET first_name =  p_first_name,
        last_name =  p_last_name,
        email =  p_email,
        phone =  p_phone,
        language =  p_language,
        status = p_status,
        privileges = p_privileges
    WHERE user_id = p_user_id;
END

Step 1: Create/Update a stored procedure
Note that this stored procedure does not update the user's password or created_at field.

    public static boolean update(User user) {
        try(Connection connection = getConnection();
        CallableStatement statement = connection.prepareCall("{CALL sp_update_user(?,?,?,?,?,?,?,?)}")
        ) {
            statement.setInt(1, user.getId());
            statement.setString(2, user.getFirstName());
            statement.setString(3, user.getLastName());
            statement.setString(4, user.getEmail());
            statement.setString(5, user.getPhone());
            statement.setString(6, user.getLanguage());
            statement.setString(7, user.getStatus());
            statement.setString(8, user.getPrivileges());
            int rowsAffected = statement.executeUpdate();
            return rowsAffected == 1;
        } catch(SQLException e) {
            System.out.println(e.getMessage());
            return false;
        }
    }

Implement a method to update a User.

UserDAO

pom.xml

public static void add(User user) {
    try (Connection connection = getConnection()) {
        if (connection != null) {
            try (CallableStatement statement = connection.prepareCall("{CALL sp_add_user(?, ?)}")) {
                statement.setString(1, user.getEmail());
                String encryptedPassword = BCrypt.hashpw(new String(user.getPassword()), BCrypt.gensalt(12));
                statement.setString(2, encryptedPassword);
                statement.executeUpdate();
            }
        }
    } catch (SQLException e) {
        throw new RuntimeException(e);
    }
}

Add this dependency to the pom.xml file to handle password encryption.

Implement a method to add a User.
The stored procedure was created in the Week 1 presentation.

UserDAO

if (!errorFound) {
    try {
        UserDAO.add(user);
        req.setAttribute("userAddSuccess", "User added");
    } catch (RuntimeException e) {
        req.setAttribute("userAddFail", "User not added");
    }
}

After checking if there are errors and before you forward the request and response to the servlet, if there are no errors, call the method to add a user to the database.

Signup Servlet

<c:if test="${not empty userAddSuccess}">
    <div class="alert alert-success mb-2" role="alert">${userAddSuccess}</div>
</c:if>
<c:if test="${not empty userAddFail}">
    <div class="alert alert-danger mb-2" role="alert">${userAddFail}</div>
</c:if>

Add code before the form to display a message.

signup.jsp

Test out the form. If you get a success message go to MySQL workbench and run: SELECT * FROM users;
To test the fail message, create a user with the same email address.
If you add two users with different email addresses but the same password, you will notice their hashed passwords are different.

<c:choose>
    <c:when test="${not empty flashMessageSuccess}">
        <div class="alert alert-success mb-2" role="alert">
                ${flashMessageSuccess}
        </div>
        <c:remove var="flashMessageSuccess" scope="session" />
    </c:when>
    <c:when test="${not empty flashMessageDanger}">
        <div class="alert alert-danger mb-2" role="alert">
                ${flashMessageDanger}
        </div>
        <c:remove var="flashMessageDanger" scope="session" />
    </c:when>
    <c:when test="${not empty flashMessageWarning}">
        <div class="alert alert-warning mb-2" role="alert">
                ${flashMessageWarning}
        </div>
        <c:remove var="flashMessageWarning" scope="session" />
    </c:when>
</c:choose>

In top.jsp, after including top-nav.jsp, add the following c:choose statement.
- Success messages display green.
- Danger messages display red.
- Warning messages display yellow.
The c:remove statement is used to remove a session attribute after it is used.

Flash Message

HttpSession session = req.getSession(); // Get existing session 
session.invalidate(); // Remove all existing session attributes
session = req.getSession(); // Create new session
user.setStatus("active");
UserDAO.update(user);
user.setPassword(null);
session.setAttribute("activeUser", userFromDatabase);
session.setAttribute("flashMessageSuccess", "Welcome!");
resp.sendRedirect(req.getContextPath()); // Redirects to the home page
return;

Replace this code...
req.setAttribute("userAddSuccess", "User added");
with the following...

Signup Servlet

Delete any previous database records before continuing.
DELETE FROM user;
Run the program. Create a new user. If successful, you will be redirected to the home page and see a success flash message.
Run this SQL to confirm the user's account is active.

SELECT * FROM user;

SQL

Edit the Sign Up and Sign In buttons so they only display when the "activeUser" session variable is not set.
When "activeUser" is set, display the My Account and Sign Out buttons.

top-nav.jsp

<div class="d-lg-flex col-lg-3 justify-content-lg-end">
<c:choose>
    <c:when test="${empty sessionScope.activeUser}">
       <a href="#" class="btn btn-outline-primary me-2">Login</a>
       <a href="signup" class="btn btn-primary">Sign-up</a>
    </c:when>
    <c:otherwise>
       <a href="#" class="btn btn-outline-secondary me-2">Edit Profile</a>
       <a href="signout" class="btn btn-secondary">Sign out</a> 
    </c:otherwise>
</div>

Assuming the session was just created, and you are on the homepage with the flash message displaying, if you refresh the page the flash message will disappear and the Login/Sign-up buttons will become a Edit Profile/Sign uut buttons.

Sign in

Create a new servlet called "SignoutServlet". Add this code.

Signout Servlet

import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import jakarta.servlet.http.HttpSession;

import java.io.IOException;
@WebServlet("/signout")
public class SignoutServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        HttpSession session = req.getSession(); // Get existing session
        session.invalidate(); // Remove all existing session attributes
        session = req.getSession(); // Create new session
        session.setAttribute("flashMessageWarning", "You are logged out. See you next time!");
        resp.sendRedirect(req.getContextPath()); // Redirects to the home page
    }
}

Get User By ID

CREATE PROCEDURE sp_get_user_by_id(IN p_user_id int)
BEGIN
    SELECT user_id, first_name, last_name, email, phone, password, language, status, privileges, created_at
    FROM user
    WHERE user_id = p_user_id;
END

Step 1: Create/Update a stored procedure

Delete User

CREATE PROCEDURE sp_delete_user(IN p_user_id int)
BEGIN
    DELETE FROM user WHERE user_id = p_user_id;
END;

Step 1: Create/Update a stored procedure

Java 3 - Week 2

By Marc Hauschildt

Java 3 - Week 2

Marc Hauschildt

Web Technologies and Computer Software Development Instructor at Kirkwood Community College in Cedar Rapids, IA.

kirkwood.edu/businessit

Java 3

top-nav

bottom-nav

top.jsp

taglib directives

bottom.jsp

Home Servlet

Including files

Home Page Content

Custom CSS

Signup Servlet

Including files

Signup Form

Signup Form

Signup Servlet doPost

Signup Servlet processRequest

signup.jsp

Validators

User class

Signup Servlet

signup.jsp

signup.jsp

Get User By Email

UserDAO

Signup Servlet

Update User

UserDAO

pom.xml

UserDAO

Signup Servlet

signup.jsp

Flash Message

Signup Servlet

SQL

top-nav.jsp

Sign in

Signout Servlet

Get User By ID

Delete User

Java 3 - Week 2

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