【Java】實作透過Gmail SMTP Server 發送信件 版本三

改寫版本二的內容(尚未測試，ps筆者跑太多次，gmail被暫停使用)：

1. 參考至這篇TLS加密並不是明文傳送。若要用密文傳送需要用SSL，且設定需要用SMTPS。
   (若需測試使用，下面兩行註解拿掉)
   // if (this.secureType == secureType.SSL)
// protocol = SMTPS;
2. 更貼近E-mail功能，使寄件者以及收信者均包含名字以及email地址，也可以設定同時多個收信者。所以增加：EmailSender和EmailReceiver。
3. Properties 參數可以參考：Package com.sun.mail.smtp

EmailSender.java

class EmailSender{
	String name;
	String address;
	
	EmailSender(){
		name = "";
		address = "";
	}	
}

EmailReceiver.java

public interface EmailReceiver {
	String name();
	String address();
}


Email.java 
package option;

import java.text.DateFormat;
import java.util.Date;
import java.util.Properties;
import java.util.Vector;

import javax.mail.Address;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import option.GmailSetting.SecureType;

public class Email {

	String subject;
	String content;
	SecureType secureType;
	boolean valid;
	String account;
	String passowrd;
	EmailSender emailSender;
	Vector<EmailReceiver> emailReceivers;

	static final String SMTP = "smtp";
	static final String SMTPS = "smtps";

	Email(SecureType secureType, boolean valid, String account, String password) {
		subject = "";
		content = "";
		this.secureType = secureType;
		this.valid = valid;
		this.account = account;
		this.passowrd = password;
		emailSender = new EmailSender();
		emailReceivers = new Vector<EmailReceiver>();
	}

	public void setSubject(String subject) {
		this.subject = subject;
	}

	public void setContents(String content) {
		this.content = content;
	}

	public void setSender(String name, String address) {
		emailSender.name = name;
		emailSender.address = address;
	}

	public void addReceiver(final String name, final String address) {
		emailReceivers.add(new EmailReceiver() {
			public String address() {
				return address;
			}

			public String name() {
				return name;
			}
		});
	}

	Properties generateRequireProp() {

		String protocol = SMTP;
		final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
		String portNumber = GmailSetting.PORT_NUMBER.get(secureType.value()).toString();

		//
		// if (this.secureType == secureType.SSL)
		// protocol = SMTPS;

		// set up gmail information
		Properties props = new Properties();
		props.setProperty("mail." + protocol + ".host", "smtp.gmail.com");
		props.setProperty("mail." + protocol + ".port", portNumber);
		props.setProperty("mail.transport.protocol", protocol);

		if (valid)
			props.setProperty("mail" + protocol + ".smtp.auth", "true");

		if (this.secureType != SecureType.None) {
			if (this.secureType == secureType.TLS)
				props.setProperty("mail." + protocol + ".smtp.starttls.enable", "true");
			else {
				props.setProperty("mail." + protocol + ".socketFactory.class", SSL_FACTORY);
				props.setProperty("mail." + protocol + ".socketFactory.fallback", "false");
				props.setProperty("mail." + protocol + ".socketFactory.port", portNumber);
				props.setProperty("mail." + protocol + ".smtps.ssl.enable", "true");

			}
		}
		return props;
	}

	boolean sendMail() {
		try {
			if (emailReceivers.isEmpty()) {
				System.out.println("Email Receiver is empty.");
				return false;
			}

			System.out.println("Start to send email");

			int receiverAddressCount = emailReceivers.size();
			Address[] mailAddress = new Address[receiverAddressCount];
			for (int i = 0; i < receiverAddressCount; i++) {
				mailAddress[i] = new InternetAddress(emailReceivers.get(i).address(), emailReceivers.get(i).name());
			}

			Address senderAddress = new InternetAddress(emailSender.address, emailSender.name);

			Properties props = generateRequireProp();

			// build the new session service
			Session session = Session.getInstance(props, null);

			Message message = new MimeMessage(session);

			// build the mail of sender , receiver and subject info
			message.setHeader("Content-Transfer-Encoding", "utf-8");
			message.setFrom(senderAddress);
			message.setRecipients(Message.RecipientType.TO, mailAddress);
			message.setSubject(subject);

			// set mime content
			MimeMultipart multipart = new MimeMultipart();
			MimeBodyPart messageBodyPart = new MimeBodyPart();
			messageBodyPart.setContent(content + "by " + secureType.value() + " connection.", "text/html;charset=utf-8");
			multipart.addBodyPart(messageBodyPart);
			message.setContent(multipart);

			message.saveChanges();
			String protocol = SMTP;

			if (valid) {
				Transport transport = session.getTransport();
				if (this.secureType == secureType.SSL)
					protocol = SMTPS;
				transport = session.getTransport(protocol);
				transport.connect("smtp.gmail.com", this.account, this.passowrd);
				Transport.send(message, message.getAllRecipients());
				transport.close();
			} else {
				Transport.send(message);

			}
			System.out.println("Done");

		} catch (Exception e) {
			// throw new RuntimeException(e);
			e.printStackTrace();
		}
		return true;

	}

	public static void main(String args[]) {

		final String senderAddr = "sender@gmail.com";
		final String password = "sender password";

		Email testEmail = new Email(SecureType.SSL, true, senderAddr, password);
		testEmail.setSubject("Test mail " + DateFormat.getDateTimeInstance().format(new Date(System.currentTimeMillis())));
		testEmail.setContents("This is a test e-mail by javamail library");
		testEmail.addReceiver("Test123", "receiver@mail");
		testEmail.setSender("SenderTest by Jorden", senderAddr);

		if (testEmail.sendMail())
			System.out.println("Success to send email!");

		else
			System.out.println("Error");
	}
}

【Java】實作透過Gmail SMTP Server 發送信件 版本二

本實作是改寫上篇透過SSL加密寄信；新增TLS以及None的方法。
因為Gmail已經不提供None(不加密)的寄信，所以在執行None方法時，會出現問題。

這部分除了改寫原本code以外，新增一個class放置gmail secure設定以及對應的port number。

Email.java

package option;

import java.text.DateFormat;
import java.util.Date;
import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import option.GmailSetting.*;

public class Email {

	String subject;
	String content;
	String receiver;
	SecureType secureType;

	Email(SecureType secureType) {
		subject = "";
		content = "";
		receiver = "";
		this.secureType = secureType;
	}

	public void setSubject(String subject) {
		this.subject = subject;
	}

	public void setContents(String content) {
		this.content = content;
	}

	public void setReceiverAddress(String address) {
		this.receiver = address;
	}

	Properties generateRequireProp() {

		final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
		String portNumber = GmailSetting.PORT_NUMBER.get(secureType.value()).toString();

		// set up gmail smtp information
		Properties props = new Properties();
		props.setProperty("mail.smtp.host", "smtp.gmail.com");
		props.setProperty("mail.transport.protocol", "smtp");
		props.setProperty("mail.smtp.auth", "true");
		props.setProperty("mail.smtp.port", portNumber);

		if (this.secureType != SecureType.None) {
			if (this.secureType == secureType.TLS)
				props.setProperty("mail.smtp.starttls.enable", "true");
			else {
				props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
				props.setProperty("mail.smtp.socketFactory.fallback", "false");
				props.setProperty("mail.smtp.socketFactory.port", portNumber);
				props.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
			}
		}
		return props;
	}

	boolean sendMail() {
		if (this.receiver.equals("")) {
			System.out.println("Email Receiver is empty.");
			return false;
		}

		System.out.println("Start to send email");
		Properties props = generateRequireProp();
		final String username = "sender@gmail.com";
		final String password = "sender password";

		// build the new session service
		Session session = Session.getInstance(props, new Authenticator() {
			protected PasswordAuthentication getPasswordAuthentication() {
				return new PasswordAuthentication(username, password);
			}
		});

		try {
			Message message = new MimeMessage(session);

			// build the mail of sender , receiver and subject info
			message.setFrom(new InternetAddress(username));
			message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(receiver, false));
			message.setSubject(subject);

			// set mime content
			MimeMultipart multipart = new MimeMultipart();
			MimeBodyPart messageBodyPart = new MimeBodyPart();
			messageBodyPart.setContent(content + "by " + secureType.value() + " connection.", "text/html;charset=utf-8");
			multipart.addBodyPart(messageBodyPart);
			message.setContent(multipart);

			Transport.send(message);
			System.out.println("Done");

		} catch (Exception e) {
			throw new RuntimeException(e);
		}
		return true;

	}

	public static void main(String args[]) {

		Email email = new Email(SecureType.SSL);
		email.setSubject("Test mail " + DateFormat.getDateTimeInstance().format(new Date(System.currentTimeMillis())));
		email.setContents("This is a test e-mail by javamail library");
		email.setReceiverAddress("receiver@mail");

		if (email.sendMail())
			System.out.println("Success to send email!");

		else
			System.out.println("Error");

	}
}



GmailSetting.java
package option;

import java.util.HashMap;
import java.util.Map;

public class GmailSetting {
	SecureType secureType;

	public GmailSetting() {
		// TODO Auto-generated constructor stub
	}

	public enum SecureType {
		None, SSL, TLS;

		public String value() {
			return name();
		}

		public static SecureType fromValue(String v) {
			return valueOf(v);
		}
	}

	static final Map<String, Integer> PORT_NUMBER = new HashMap<String, Integer>() {
		private static final long serialVersionUID = -5199045595923410899L;
		{
			put("None", 25);
			put("SSL", 465);
			put("TLS", 587);
		}
	};

}

【Java】實作透過Gmail SMTP Server 發送信件(利用javamail API)

連線加密方式有三種：

1. None(不加密)
2. TLS , port number:587
3. SSL , port number:465 (參考網址)

這裡實作以SSL加密寄送信件。
需要包裝javamail API到lib，下例用JavaMail 1.4.2進行包裝。

注意： 若發送信件內容，不只是純文字，而有用到html、CSS。
經過測試後，確定gmail 不支援部分block css內容，若可行，請寫inline css。
其他html email設計的要素，參考：

1. Guide to CSS support in email 
2. How HTML email works, basic concepts, best practices, tips and tricks

package option;

import java.text.DateFormat;
import java.util.Date;
import java.util.Properties;

import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

public class Email {

 String subject;
 String content;
 String receiver;

 Email() {
  subject = "";
  content = "";
  receiver = "";
 }

 public void setSubject(String subject) {
  this.subject = subject;
 }

 public void setContents(String content) {
  this.content = content;
 }

 public void setReceiverAddress(String address) {
  this.receiver = address;
 }

 static Properties generateRequireProp() {

  final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
  
  // set up gmail information
  Properties props = new Properties();
  props.setProperty("mail.smtp.host", "smtp.gmail.com");
  props.setProperty("mail.smtp.socketFactory.class", SSL_FACTORY);
  props.setProperty("mail.smtp.socketFactory.fallback", "false");
  props.setProperty("mail.smtp.socketFactory.port", "465");
  props.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
  props.setProperty("mail.smtp.auth", "true");
  props.setProperty("mail.smtp.port", "465");

  return props;
 }

 boolean send() {
  if (receiver.equals("")) {
   System.out.println("Email Receiver is empty.");
   return false;
  }

  Properties props = generateRequireProp();
  final String username = "sender@gmail.com";
  final String password = "sender password";

  // build the new session service
  Session session = Session.getInstance(props, new Authenticator() {
   protected PasswordAuthentication getPasswordAuthentication() {
    return new PasswordAuthentication(username, password);
   }
  });

  try {   
   Message message = new MimeMessage(session);
   
   //build the mail of sender , receiver and subject info 
   message.setFrom(new InternetAddress(username));
   message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(receiver, false));
   message.setSubject(subject);
   
   // set mime content
   MimeMultipart multipart = new MimeMultipart();
   MimeBodyPart messageBodyPart = new MimeBodyPart();
   messageBodyPart.setContent(content, "text/html;charset=utf-8");
   multipart.addBodyPart(messageBodyPart);
   message.setContent(multipart);

   Transport.send(message);
   System.out.println("Done");

  } catch (Exception e) {
   throw new RuntimeException(e);
  }
  return true;

 }

 public static void main(String args[]) {

  Email email = new Email();
  email.setSubject("Test mail "+DateFormat.getDateTimeInstance().format(new Date(System.currentTimeMillis())));
  email.setContents("This is a test e-mail by javamail library");
  email.setReceiverAddress("receiver@mail");

  if (email.send())
   System.out.println("Sending is successing");

  else
   System.out.println("Error");

 }
}