Java发送Email/邮件

使用Java应用程序发送邮件是很简单的，需要安装JavaMail API 和Java Activation Framework (JAF) 在机器上。

• 可以从Java的标准网站上下载JavaMail（版本1.2）的最新版本。

• 可以从Java的标准网站下载最新版本的JAF（版本1.1.1）。

下载并解压缩这些文件，在新创建的顶层目录，会发现一些jar文件应用。需要添加了mail.jar和activation.jar文件在CLASSPATH中。

发送一个简单的E-mail：

下面是一个例子，从机器发送一个简单的电子邮件。这里假设你的电脑已经可以连接到互联网，并有足够的能力来发送电子邮件。

 // 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 = "abcd@gmail.com";        // Sender's email ID needs to be mentioned       String from = "web@gmail.com";        // 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();       }    } }

编译并运行这个程序发送一个简单的电子邮件：

 $ java SendEmail Sent message successfully....

如果想发送电子邮件给多个收件人，然后下面的方法将被用来指定多个电子邮件标识：

 void addRecipients(Message.RecipientType type,                     Address[] addresses) throws MessagingException

这里的参数的说明：

• type: 这将被设定为TO，CC或BCC。在这里，CC代表抄送和BCC代表黑抄送。例子Message.RecipientType.TO

• addresses: 这是电子邮件的ID的数组。需要使用InternetAddress() 方法，同时指定电子邮件ID

Send an HTML E-mail:

下面是一个例子，从机器发送的HTML电子邮件。这里假设你的本地主机连接到互联网，并有足够的能力来发送电子邮件。

这个例子非常相似，前一个，除了在这里我们使用的是使用setContent()方法来设置内容的第二个参数是"text/html"类型指定的HTML内容被包含在消息中。

通过这个例子，可以发送大如喜欢HTML内容。

 // 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 = "abcd@gmail.com";        // Sender's email ID needs to be mentioned       String from = "web@gmail.com";        // 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();       }    } }

编译并运行这个程序来发送HTML电子邮件：

 $ java SendHTMLEmail Sent message successfully....

发送附件的电子邮件：

下面是一个例子与附件从机器发送电子邮件。这里假设你的本地主机连接到互联网，并有足够的能力来发送电子邮件。

 // 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 = "abcd@gmail.com";        // Sender's email ID needs to be mentioned       String from = "web@gmail.com";        // 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();       }    } }

编译并运行这个程序来发送HTML电子邮件：

 $ java SendFileEmail Sent message successfully....

用户认证部分：

如果需要提供用户ID和密码的电子邮件服务器进行身份验证的目的，那么可以按如下方法设置这些属性：

  props.setProperty("mail.user", "myuser");  props.setProperty("mail.password", "mypwd");

邮件发送机制的其余部分将继续如上面所述。