Developing JavaServer Pages - The Code for the HTML Page that Calls the JSP (
Page 2 of 11 )
Figure 2 presents the code for the HTML page that calls the JSP. If you've read chapter 3, you shouldn't have any trouble following it. Here, the Action attribute of the Form tag calls a JSP named show_email_entry.jsp that's stored in the same directory as the HTML page, and the Method attribute specifies that the HTTP Get method should be used with this action. Then, when the user clicks on the Submit button, the browser will send a request for the JSP.
Figure 2: The code for the HTML page that calls the JSP
<!doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Chapter 4 - Email List application</title>
</head>
<body>
<h1>Join our email list</h1>
<p>To join our email list, enter your name and
email address below. <br>
Then, click on the Submit button.</p>
<form action="show_email_entry.jsp" method="get">
<table cellspacing="5" border="0">
<tr>
<td align="right">First name:</td>
<td><input type="text" name="firstName"></td>
</tr>
<tr>
<td align="right">Last name:</td>
<td><input type="text" name="lastName"></td>
</tr>
<tr>
<td align="right">Email address:</td>
<td><input type="text" name="emailAddress"></td>
</tr>
<tr>
<td></td>
<td><br><input type="submit" value="Submit"></td>
</tr>
</table>
</form>
</body>
</html>
You should also notice the Name attributes of the three text boxes that are used in the table within this HTML page. These are the names of the parameters that are passed to the JSP when the user clicks on the Submit button. In Figure 1, the parameter names are firstName, lastName, and emailAddress and the parameter values are John, Smith, and jsmith@hotmail.com.
Figure 3 presents the code for the JSP. As you can see, much of the JSP code is HTML. In addition, though, Java code is embedded within the HTML code in the form of JSP scriptlets and expressions. Typically, a scriptlet is used to execute one or more Java statements while a JSP expression is used to display text. To identify scriptlets and expressions, JSPs use tags. To distinguish them from HTML tags, you can refer to them as JSP tags.
Figure 3: The Code for the JSP
<!doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Chapter 4 - Email List application</title>
</head>
<body>
< %
String firstName = request.getParameter("firstName");
String lastName = request.getParameter("lastName");
String emailAddress = request.getParameter("emailAddress");
% >
<h1>Thanks for joining our email list</h1>
<p>Here is the information that you entered:</p>
<table cellspacing="5" cellpadding="5" border="1">
<tr>
<td align="right">First name:</td>
<td><%= firstName %></td>
</tr>
<tr>
<td align="right">Last name:</td>
<td><%= lastName %></td>
</tr>
<tr>
<td align="right">Email address:</td>
<td><%= emailAddress %></td>
</tr>
</table>
<p>To enter another email address, click on the Back <br>
button in your browser or the Return button shown <br>
below.</p>
<form action="join_email_list.html" method="post">
<input type="submit" value="Return">
</form>
</body>
</html>
|
 Remember: this is from chapter four of Joel Murach's Java Servlets and JSP (Mike Murach & Associates, ISBN 1890774189, 2003). Grab a copy at your favorite book store today!
Buy this book now. |
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