Sending Emails using JavaServer Pages

In this article we will learn how to send plain text emails using JSP pages. Since it is not a good habit to put Java code in JSP pages, we will create a JavaBean to send the emails for us.

Why will you need to send emails from your website?
Following are just a few reason why you will need to send emails from your website, enterprise application etc :

• To put feedback forms on your site, allowing users to easily send comments and suggestions to you regarding the content on your web site.
• Sending confirmation emails to buyers that the product they bought will be sent to them in this much time.
• To program your application in such a way to send you ( the webmaster ) email whenever some thing important goes down on your web site e.g. database server crashes.
• To send emails to mailing list. This is a rather important use and I will probably describe it in a separate article.

Well, above were only few points which came to my mind, but I know that you understand that you need to have this capability on your web site.

Requirements
You need to have at least a JSP 1.1 capable application server or Servlet container. Almost all of the application servers, servlet containers I know are capable of JSP 1.1 so it shouldn't be any problem. The least you can do is to download and install Tomcat server. I have explained every step from downloading to installing and running Tomcat server in a separate article. You can read it from there.

Next you need to have JavaMail ( mail.jar ) jar file in your application server's classpath. Download the latest JavaMail 1.2 jar file from Sun's JavaMail web site and put it in your server /lib folder. Most application servers have a "lib" ( stands for library ) folder where you can put the jar files you need your server to know about. If your application server doesn't have a lib folder, you should consult it's documentation as to where additional jar files should be put.

If nothing works you can at least put the jar file in your web application's /WEB-INF/lib folder. This should work. Still if nothing works, you can post your question here at the bottom of this article.

One last thing you need to have in your application server's classpath is Java Activation Framework jar file. You can download it from here. It is needed by the JavaMail class files. Once both activation.jar and mail.jar files are in your server's classpath or in your web application's WEB-INF/lib folder, you are ready to move forward.

Building the application
To demonstrate how to send emails, we'll create just 4 files :

• index.html
  A simple HTML page which displays a form to you containing few input fields. Here you will enter the sender's and receiver's email addresses, subject and message of the email.
• mailer.jsp
  The JSP page which calls the MailerBean to send email. Since all the work is done by the MailerBean, this JSP page is simpler than you can imagine.
• errorPage.jsp
  An error page which will catch any exceptions thrown by mailer.jsp ( from the MailerBean ) JSP page and show it to the user. Exceptions can be thrown when for instance you enter an illegal receiver's email address, or simply forget to enter anything in the receiver's input field.
• MailerBean.class
  The actual bean which does all the hard work of sending emails for us.

Advice
Just in case if you are wondering that it is taking more effort than you thought as you have to create two extra files; errorPage.jsp and MailerBean, you are right. I could have easily cluttered the mailer.jsp page will all the Java code required to send emails but then it'll be wrong. What if you happen to require sending emails in another JSP page for instance? will you copy all the code from mailer.jsp to that page? you shouldn't do that. Encapsulating all the code in MailerBean allows us to use this bean from anywhere we want. You can use it from within JSP pages, Servlets, other beans or even EJBs and standalone applications. Using JavaBeans allows a great deal of scalability.

The second extra page, errorPage.jsp is an error page which will catch the ugly exceptions from within mailer.jsp page show it in a rather friendly environment to the user. I have added this error page here so that you also learn good practices while learing J2EE.

To sum up, scalability is the key. If you ever happen to come across a solution which in not scalable, doesn't matter how good it is, my advice is to stay away from it.

i. index.html
Create a new folder in your web application folder and give it any name. For example's sake, I will call this folder "mail". Now create a new index.html HTML page in it and copy the following text in it :

<html>
<head>
	<style>
	div,input,textarea { font-family:Tahoma; font-size:8pt; }
	input.std { width:200; }
	div.frame { padding-left:70; }
	</style>
</head>
<body>

<div class="frame">
	<form action="mailer.jsp" method="post">
	To :<br>
	<input type="text" name="to" class="std"></input><br>
	From :<br>
	<input type="text" name="from" class="std"></input><br>
	Subject :<br>
	<input type="text" name="subject" class="std"></input><br>
	Message :<br>
	<textarea rows="10" cols="80" name="message"></textarea>
	<br>
	<input type="submit" value="Send"></input>
	</form>
</div>

</body>
</html>

As you can see it is a simple HTML page which displays a form to the user containing 3 input and 1 big textarea field. The 2 input fields are for receiver's and sender's email address, while the 3rd field is for the subject of the email.

ii. mailer.jsp
Create a new JSP page and save it as "mailer.jsp" in the same folder as the one in which you placed index.html. Copy the following code and paste it in mailer.jsp page :

<%@ page errorPage="errorPage.jsp" %>

<html>
<head>
	<style>
	div,input,textarea { font-family:Tahoma; font-size:8pt; }
	input.std { width:200; }
	div.frame { padding-left:70; color:green; }
	</style>
</head>
<body>
	<div class="frame">
	<jsp:useBean id="mailer" class="com.stardeveloper.bean.test.MailerBean">
		<jsp:setProperty name="mailer" property="*"/>
		<% mailer.sendMail(); %>
	</jsp:useBean>
	Email has been sent successfully.
	</div>
</body>
</html>

Explanation
First important thing to notice is the "errorPage" attribute in the "page" directive at the top. It tells the servlet container that this page makes use of an error page so any exception which is thrown in this page should be made available to the error page, where we show it to the user.