在本章中，我们将讨论如何使用JSP发送电子邮件.要使用JSP发送电子邮件，您应该在计算机上安装 JavaMail API 和 Java Activation Framework(JAF).
您可以下载最新版本的 JavaMail(版本1.2).
您可以下载最新版本的JavaBeans Activation Framework JAF(版本1.0.2).
在新创建的顶级目录中下载并解压缩这些文件.您将找到两个应用程序的jar文件.您需要在CLASSPATH中添加 mail.jar 和 activation.jar 文件.
以下是从您的计算机发送简单电子邮件的示例.假设您的 localhost 已连接到Internet，并且它足以发送电子邮件.确保来自Java Email API包和JAF包的所有jar文件都在CLASSPATH中可用.
<%@ page import = "java.io.*,java.util.*,javax.mail.*"%>
<%@ page import = "javax.mail.internet.*,javax.activation.*"%>
<%@ page import = "javax.servlet.http.*,javax.servlet.*" %>
<%
String result;
// Recipient's email ID needs to be mentioned.
String to = "abcd@gmail.com";
// Sender's email ID needs to be mentioned
String from = "mcmohd@gmail.com";
// Assuming you are sending email from localhost
String host = "localhost";
// Get system properties object
Properties properties = System.getProperties();
// Setup mail server
properties.setProperty("mail.smtp.host", host);
// Get the default Session object.
Session mailSession = Session.getDefaultInstance(properties);
try {
// Create a default MimeMessage object.
MimeMessage message = new MimeMessage(mailSession);
// Set From: header field of the header.
message.setFrom(new InternetAddress(from));
// Set To: header field of the header.
message.addRecipient(Message.RecipientType.TO,
new InternetAddress(to));
// Set Subject: header field
message.setSubject("This is the Subject Line!");
// Now set the actual message
message.setText("This is actual message");
// Send message
Transport.send(message);
result = "Sent message successfully....";
} catch (MessagingException mex) {
mex.printStackTrace();
result = "Error: unable to send message....";
}
%>
<html>
<head>
<title>Send Email using JSP</title>
</head>
<body>
<center>
<h1>Send Email using JSP</h1>
</center>
<p align = "center">
<%
out.println("Result: " + result + "\n");
%>
</p>
</body>
</html>现在让我们将上面的代码放在 SendEmail.jsp 文件中，并使用URL http:/调用此JSP/localhost:8080/SendEmail.jsp 的.这有助于向指定的电子邮件ID abcd@gmail.com 发送电子邮件.您将收到以下回复 :
Send Email using JSPResult: Sent message successfully....
如果要向多个收件人发送电子邮件，则使用以下方法指定多个电子邮件ID :
void addRecipients(Message.RecipientType type, Address[] addresses) throws MessagingException
以下是参数的说明 :
输入 : 这将设置为TO，CC或BCC.此处CC表示碳复制，BCC表示黑碳复制.示例 Message.RecipientType.TO
地址 : 这是电子邮件ID的数组.您需要在指定电子邮件ID时使用InternetAddress()方法
以下是从您的计算机发送HTML电子邮件的示例.假设您的 localhost 已连接到Internet，并且它足以发送电子邮件.确保 Java Email API包中的所有jar文件和 JAF包在CLASSPATH中可用.
这个例子非常与前一个类似，不同之处在于我们使用 setContent()方法设置第二个参数为"text/html"的内容，以指定HTML内容为包含在消息中.
使用此示例，您可以根据需要发送大量HTML内容.
<%@ page import = "java.io.*,java.util.*,javax.mail.*"%>
<%@ page import = "javax.mail.internet.*,javax.activation.*"%>
<%@ page import = "javax.servlet.http.*,javax.servlet.*" %>
<%
String result;
// Recipient's email ID needs to be mentioned.
String to = "abcd@gmail.com";
// Sender's email ID needs to be mentioned
String from = "mcmohd@gmail.com";
// Assuming you are sending email from localhost
String host = "localhost";
// Get system properties object
Properties properties = System.getProperties();
// Setup mail server
properties.setProperty("mail.smtp.host", host);
// Get the default Session object.
Session mailSession = Session.getDefaultInstance(properties);
try {
// Create a default MimeMessage object.
MimeMessage message = new MimeMessage(mailSession);
// Set From: header field of the header.
message.setFrom(new InternetAddress(from));
// Set To: header field of the header.
message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
// Set Subject: header field
message.setSubject("This is the Subject Line!");
// Send the actual HTML message, as big as you like
message.setContent("<h1>This is actual message</h1>", "text/html" );
// Send message
Transport.send(message);
result = "Sent message successfully....";
} catch (MessagingException mex) {
mex.printStackTrace();
result = "Error: unable to send message....";
}
%>
<html>
<head>
<title>Send HTML Email using JSP</title>
</head>
<body>
<center>
<h1>Send Email using JSP</h1>
</center>
<p align = "center">
<%
out.println("Result: " + result + "\n");
%>
</p>
</body>
</html>现在让我们使用上面的JSP在给定的电子邮件ID上发送HTML消息.
以下是从您的机器发送带附件的电子邮件的示例 :
<%@ page import = "java.io.*,java.util.*,javax.mail.*"%>
<%@ page import = "javax.mail.internet.*,javax.activation.*"%>
<%@ page import = "javax.servlet.http.*,javax.servlet.*" %>
<%
String result;
// Recipient's email ID needs to be mentioned.
String to = "abcd@gmail.com";
// Sender's email ID needs to be mentioned
String from = "mcmohd@gmail.com";
// Assuming you are sending email from localhost
String host = "localhost";
// Get system properties object
Properties properties = System.getProperties();
// Setup mail server
properties.setProperty("mail.smtp.host", host);
// Get the default Session object.
Session mailSession = Session.getDefaultInstance(properties);
try {
// Create a default MimeMessage object.
MimeMessage message = new MimeMessage(mailSession);
// Set From: header field of the header.
message.setFrom(new InternetAddress(from));
// Set To: header field of the header.
message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
// Set Subject: header field
message.setSubject("This is the Subject Line!");
// Create the message part
BodyPart messageBodyPart = new MimeBodyPart();
// Fill the message
messageBodyPart.setText("This is message body");
// Create a multipart message
Multipart multipart = new MimeMultipart();
// Set text message part
multipart.addBodyPart(messageBodyPart);
// Part two is attachment
messageBodyPart = new MimeBodyPart();
String filename = "file.txt";
DataSource source = new FileDataSource(filename);
messageBodyPart.setDataHandler(new DataHandler(source));
messageBodyPart.setFileName(filename);
multipart.addBodyPart(messageBodyPart);
// Send the complete message parts
message.setContent(multipart );
// Send message
Transport.send(message);
String title = "Send Email";
result = "Sent message successfully....";
} catch (MessagingException mex) {
mex.printStackTrace();
result = "Error: unable to send message....";
}
%>
<html>
<head>
<title>Send Attachment Email using JSP</title>
</head>
<body>
<center>
<h1>Send Attachment Email using JSP</h1>
</center>
<p align = "center">
<%out.println("Result: " + result + "\n");%>
</p>
</body>
</html>现在让我们运行上面的JSP来发送文件作为附件以及给定电子邮件ID上的消息.
如果需要向电子邮件服务器提供用户ID和密码以进行身份验证，则可以将这些属性设置为以下 :
props.setProperty("mail.user", "myuser");
props.setProperty("mail.password", "mypwd");其余的电子邮件发送机制将保持如上所述.
您可以使用HTML表单接受电子邮件参数，然后您可以使用请求对象获取以下所有信息 :
String to = request.getParameter("to");
String from = request.getParameter("from");
String subject = request.getParameter("subject");
String messageText = request.getParameter("body");获得所有信息后，您可以使用上述程序发送电子邮件.
