封装良好的java mail工具，支持附件，群发，抄送，认证，无认证，ssl，html格式

import java.io.File;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Properties;
import java.util.Map.Entry;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.Authenticator;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import com.ourlinc.swift.util.Misc;

public class Mail {
private Session session = null;
private Properties properties = System.getProperties();
private Authenticator authenticator = null;
private HashMap<String, String> mailAttachment = new HashMap<String, String>();

public static void main(String[] args) {
List<String> to = new ArrayList<String>();
to.add("aa@qq.com");
new Mail().send("aa@bb.com",to , null, "测试外部邮箱", "正文");
}

/**
* No SMTP auth and no SSL，使用默认邮件发送服务器172.16.1.153
*/
public Mail(){
this("172.16.1.153", false, null, null, false, null);
}

/**
* No SMTP auth and no SSL
*/
public Mail(String smtpHost) {
this(smtpHost, false, null, null, false, null);
}

/**
* SMTP auth with SSL
*/
public Mail(String smtpHost, final String username, final String password,
String sslPort) {
this(smtpHost, true, username, password, true, sslPort);
}

/**
* SMTP auth without SSL
*/
public Mail(String smtpHost, final String username, final String password) {
this(smtpHost, true, username, password, false, null);
}

/**
* All in one setting
*/
public Mail(String smtpHost, boolean needAuth, final String username,
final String password, boolean isSSL, String sslPort) {
setSMTPHost(smtpHost);
if (isSSL) {
enableSSL(sslPort);
}
if (needAuth) {
enableAuth(username, password);
}
session = getSession(needAuth);
}

/**
* Add attachment to email.
*/
public void addAttachment(String filePath) {
if (isStringEmpty(filePath)) {
throw new RuntimeException("[Error] Attachment filepath is empty!");
}
mailAttachment.put(filePath, new File(filePath).getName());
}

/**
* Send email from specified from-address to specified to-addresses /
* cc-addresses with given subject and content.
* <p>
* If already call addAttachment, the method will try to include them into
* email body
*/
public void send(String fromAddress, List<String> toEmailAddresses,
List<String> ccEmailAddresses, String subject, String content) {
MimeMessage message = new MimeMessage(session);
MimeMultipart multipart = new MimeMultipart();
try {
message.setSubject(subject);
message.setRecipients(Message.RecipientType.TO,
emailToInternetAddressArray(toEmailAddresses));
message.setRecipients(Message.RecipientType.CC,
emailToInternetAddressArray(ccEmailAddresses));
message.addFrom(InternetAddress.parse(fromAddress));
message.setSentDate(new Date());
BodyPart mainBody = new MimeBodyPart();
mainBody.setContent(content, "text/plain;charset=UTF-8");
multipart.addBodyPart(mainBody);
for (Entry<String, String> e : mailAttachment.entrySet()) {
BodyPart bodyPart = new MimeBodyPart();
bodyPart.setDataHandler(new DataHandler(new FileDataSource(e
.getKey())));
bodyPart.setFileName(e.getValue());
bodyPart.setHeader("Content-ID", e.getValue());
multipart.addBodyPart(bodyPart);
}
message.setContent(multipart);
message.saveChanges();
Transport.send(message, message.getAllRecipients());
Misc.getLogger().info("Send Mail success!");

} catch (MessagingException e) {
e.printStackTrace();
}
}

private void setSMTPHost(String smtpHost) {
if (smtpHost == null) {
throw new RuntimeException("[Error] SMTP Host is empty!");
}
properties.setProperty("mail.smtp.host", smtpHost);
}

private Session getSession(boolean needAuth) {
mailAttachment.clear();
return needAuth ? session = Session.getInstance(properties,
authenticator) : Session.getInstance(properties);
}

private void enableAuth(final String username, final String password) {
if (username == null || password == null) {
throw new RuntimeException("[Error] Username or password is empty!");
}
properties.put("mail.smtp.auth", "true");
authenticator = new Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(username, password);
}
};
}

private void enableSSL(String sslPort) {
if (isStringEmpty(sslPort)) {
throw new RuntimeException("[Error] SSL port is empty!");
}
properties.setProperty("mail.smtp.socketFactory.class",
"javax.net.ssl.SSLSocketFactory");
properties.setProperty("mail.smtp.socketFactory.fallback", "false");
properties.setProperty("mail.smtp.port", sslPort);
properties.setProperty("mail.smtp.socketFactory.port", sslPort);
}

private boolean isStringEmpty(String s) {
return s == null || s.length() == 0;
}

private InternetAddress[] emailToInternetAddressArray(List<String> email)
throws AddressException {
if (email == null || 0 == email.size()) {
return new InternetAddress[0];
}
InternetAddress[] addresses = new InternetAddress[email.size()];
for (int i = 0; i < email.size(); i++) {
addresses[i] = new InternetAddress(email.get(i));
}
return addresses;
}