Delve into the use of the JavaMail API

In my previous article "Use JavaMail and JSP combined to write a simple e-mail delivery system," introduced the JavaMail and JSP in combination with the method. In fact, the JavaMail API is a fairly large system, only then a small text is not able to introduce the end of JavaMail, so I would like to take this article with you in-depth discussion about the use of JavaMail.

Question one, how can I send a simple letter?

Answer: I will explain in detail how to send a simple letter in the following example

import java.util.*;
import java.io.*;
import javax.mail.*;
Import javax.mail.internet.*;
Import javax.activation.*;
public class Sendsimplemail {
File://msgText is the body of the letter, there are two lines
static String Msgtext = "Dear mr.fangzhou\ni ' m a read Er of your net! "
file://reads three arguments from the command line, smtphost,from,to
public static void Main (String args[])
throws exception{
if ( Args.length!= 3) {
System.out.println ("Usage:java sendsimplemail");
Return
}
String SMTPHOST=ARGS[0];//SMTP server name
String from=args[1];//Sender address
String to =args[2];//delivery address
// Create Properties Object
Properties props = new properties ();
file://Create mail server
Props.put ("Mail.smtp.host", smtphost);
FILE://gets the default session
Session session = Session.getdefaultinstance (props, null);
//Create a message and define the sender's address and delivery address
MimeMessage message = new MimeMessage (session);
Message.setfrom (A new internetaddress (from));
Internetaddress[] address = {new internetaddress (to)};
MessagE.setrecipients (Message.RecipientType.TO, address);
Message.setsubject ("Hello,fangzhou");/Set Theme
Message.setsentdate (new Date ());/Set Send time
Message.settext ( Msgtext)//Set the text in the previously defined msgtext to the content of the message body
file://send mail
transport.send (message);
}
}

Question two, what if I want to add an attachment to the email?

This is also a pretty good question, to add an attachment is to use MimeBodyPart to create the message, just the above procedures can be slightly modified, for the sake of simplicity, I just use a string as an attachment content to explain how to add an attachment.

File://msgText is the body of the letter, there are two lines

static String msgText = "Dear Mr.FangZhou\nI’m a reader of your net!"
file://msgAttachment是一段字符串作为附件
static String msgAttachment = "This is an attachment string!"
. . . . . . . . .
MimeBodyPart mbp1 = new MimeBodyPart();
mbp1.setText(msgText); file://把前面定义的msgText中的文字设定为邮件正 文的内容
file://创建附件部分
MimeBodyPart mbp2 = new MimeBodyPart();
file://使用setText(text, charset)来加入附件
mbp2.setText(msgAttachment, "gb2312");
file://创建Multipart
Multipart mp = new MimeMultipart();
mp.addBodyPart(mbp1);
mp.addBodyPart(mbp2);
// 添加 Multipart到Message中
message.setContent(mp);
file://发送邮件
Transport.send(message);
}