使用Java程序发送电子邮件
使用Java应用程序发送电子邮件非常简单,但首先你应该在你的机器上安装**JavaMail API**和**Java Activation Framework (JAF)**。
你可以从Java的官方网站下载最新版本的JavaMail (1.2版本)。
你可以从Java的官方网站下载最新版本的JAF (1.1.1版本)。
下载并解压这些文件,在新创建的顶级目录中,你会找到这两个应用程序的许多jar文件。你需要将**mail.jar**和**activation.jar**文件添加到你的CLASSPATH中。
发送简单的电子邮件
这是一个从你的机器发送简单电子邮件的例子。假设你的**本地主机**已连接到互联网,并且能够发送电子邮件。
示例
// File Name SendEmail.java import java.util.*; import javax.mail.*; import javax.mail.internet.*; import javax.activation.*; public class SendEmail { public static void main(String [] args) { // Recipient's email ID needs to be mentioned. String to = "[email protected]"; // Sender's email ID needs to be mentioned String from = "[email protected]"; // Assuming you are sending email from localhost String host = "localhost"; // Get system properties Properties properties = System.getProperties(); // Setup mail server properties.setProperty("mail.smtp.host", host); // Get the default Session object. Session session = Session.getDefaultInstance(properties); try { // Create a default MimeMessage object. MimeMessage message = new MimeMessage(session); // 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); System.out.println("Sent message successfully...."); } catch (MessagingException mex) { mex.printStackTrace(); } } }
编译并运行此程序以发送简单的电子邮件:
输出
$ java SendEmail Sent message successfully....
如果你想向多个收件人发送电子邮件,则可以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:
**type** - 这将设置为TO,CC或BCC。其中CC代表抄送,BCC代表密送。例如:Message.RecipientType.TO
**addresses** - 这是一个电子邮件ID数组。在指定电子邮件ID时,需要使用InternetAddress()方法。
发送HTML电子邮件
这是一个从你的机器发送HTML电子邮件的例子。假设你的**本地主机**已连接到互联网,并且能够发送电子邮件。
此示例与前一个示例非常相似,不同之处在于我们在这里使用setContent()方法来设置内容,其第二个参数是“text/html”,用于指定邮件中包含HTML内容。
使用此示例,你可以发送任意大小的HTML内容。
示例
// File Name SendHTMLEmail.java import java.util.*; import javax.mail.*; import javax.mail.internet.*; import javax.activation.*; public class SendHTMLEmail { public static void main(String [] args) { // Recipient's email ID needs to be mentioned. String to = "[email protected]"; // Sender's email ID needs to be mentioned String from = "[email protected]"; // Assuming you are sending email from localhost String host = "localhost"; // Get system properties Properties properties = System.getProperties(); // Setup mail server properties.setProperty("mail.smtp.host", host); // Get the default Session object. Session session = Session.getDefaultInstance(properties); try { // Create a default MimeMessage object. MimeMessage message = new MimeMessage(session); // 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); System.out.println("Sent message successfully...."); } catch (MessagingException mex) { mex.printStackTrace(); } } }
编译并运行此程序以发送HTML电子邮件:
输出
$ java SendHTMLEmail Sent message successfully....
发送电子邮件附件
这是一个从你的机器发送包含附件的电子邮件的例子。假设你的**本地主机**已连接到互联网,并且能够发送电子邮件。
示例
// File Name SendFileEmail.java import java.util.*; import javax.mail.*; import javax.mail.internet.*; import javax.activation.*; public class SendFileEmail { public static void main(String [] args) { // Recipient's email ID needs to be mentioned. String to = "[email protected]"; // Sender's email ID needs to be mentioned String from = "[email protected]"; // Assuming you are sending email from localhost String host = "localhost"; // Get system properties Properties properties = System.getProperties(); // Setup mail server properties.setProperty("mail.smtp.host", host); // Get the default Session object. Session session = Session.getDefaultInstance(properties); try { // Create a default MimeMessage object. MimeMessage message = new MimeMessage(session); // 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 multipar 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); System.out.println("Sent message successfully...."); } catch (MessagingException mex) { mex.printStackTrace(); } } }
编译并运行此程序以发送HTML电子邮件:
输出
$ java SendFileEmail Sent message successfully....
用户身份验证部分
如果需要向电子邮件服务器提供用户ID和密码进行身份验证,则可以按如下方式设置这些属性:
props.setProperty("mail.user", "myuser"); props.setProperty("mail.password", "mypwd");
其余的电子邮件发送机制将与上面解释的相同。