The java mail api provided by sun company can solve this problem very well. The following are the specific ideas and codes.
1. Sending emails:
It is mainly divided into the following four steps:
a. Create a session for sending and receiving emails (you can use the java.util.properties class to write various parameters, and use the Authencator class to verify the mailbox);
b. Create mimeMessage mail from session object;
c. Create mail sending object Transport from session object;
d. There is sending object to send mail and close transport; the
code is as follows:
public class MailInit {
/**
* Initialize the email sending and receiving Session
* @author zhanghao
* 20150327
* */
public static Session init(String host,final String username,final String password){
//Initialize email related configuration information
Properties properties = new Properties();
properties.setProperty("mail.smtp.auth", "true");
properties.setProperty("mail.smtp.host", host);
properties.setProperty("mail.transport.protocol", "smtp"); //Check related?
properties.setProperty("mail.store.protocol", "pop3"); //Receive mail
//Complete email username and password verification
Authenticator authenticator = new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication(){
return new PasswordAuthentication(username, password);
}
};
//Create a Session for sending and receiving emails
Session session = Session.getInstance(properties, authenticator);
return session;
}
/**
* Mail sending (single person)
* */
public void sendSingle(String subject,String contect,String username,String password,InternetAddress address){
String host = MailInit.getHostByUserName(username);
Session session =MailInit.init(host, username, password);
//create mime mail
MimeMessage message = new MimeMessage(session);
try {
//set sender
message.setFrom(new InternetAddress(username));
// set recipient
message.addRecipient(Message.RecipientType.TO, address);
//set theme
message.setSubject("mail subject");
//set content
message.setContent(contect,"text/html;charset=utf-8");
//send email
Transport.send(message);
logger.info("Mail sent successfully!!");
} catch (MessagingException e) {
String msg = "Failed to send email!!";
logger.error(msg);
throw new RuntimeException(msg);
}
}
/**
* mass mailing
* */
public void sendGroup(String subject,String contect,String username,String password,InternetAddress[] addressGroup){
String host = MailInit.getHostByUserName(username);
Session session =MailInit.init(host, username, password);
//create mime mail
MimeMessage message = new MimeMessage(session);
try {
//set sender
message.setFrom(new InternetAddress(username));
// set recipient
message.addRecipients(RecipientType.TO, addressGroup);
//set theme
message.setSubject("mail subject");
//set content
message.setContent(contect,"text/html;charset=utf-8");
//send email
Transport.send(message);
} catch (MessagingException e) {
String msg = "Failed to send email!!";
logger.error(msg);
throw new RuntimeException(msg);
}
}
2. Mail receiving is mainly divided into the following steps:
a. Create a session for sending and receiving mail (you can use the java.util.properties class to write various parameters, and use the Authencator class to verify the mailbox);
b. The session object creates the store object to connect to the mailbox;
c. The Folder folder is created by the store object (note: the open method needs to be used to open the folder after the creation is completed);
d. The instance of the Folder calls the getMessage method to return the Message array to get the mail content.
code show as below:
public void receiveMail(String username,String password){
String host = MailInit.getPop3ByUserName(username);
Session session =MailInit.init(host, username, password);
//create store
Store store;
try {
store = session.getStore();
store.connect(host,110,username,password);
//Open the Folder after the connection is complete
Folder folder = store.getFolder("INBOX"); //INBOX is the only folder that POP3 can use. If using IMAP, other folders are also available.
folder.open(Folder.READ_ONLY);
Message[] messages = folder.getMessages();
for (Message message : messages) {
System.out.println(message.getSubject());
}
logger.info("Receive email successfully!!");
} catch (MessagingException e) {
String msg = "Failed to receive mail!!";
logger.error(msg);
throw new RuntimeException(msg);
}
}
Complete code download address: https://github.com/wasapii/JavaMailDemo/