Java采用SMTP协议发送邮件

示例中需要用到两个包：mail.jar和activation.jar，其下载地址为：

http://java.sun.com/products/javamail/downloads/index.html

http://java.sun.com/javase/technologies/desktop/javabeans/jaf/downloads/index.html

下载后解压，将mail.jar和activation.jar放到project里的lib文件夹中，为其配置环境变量，或在myEclipse里的"Java Build Path"中将其添加到"Libraries"。

project里有三个类：入口类（TestJavaMail）、邮件信息类（MailBean）和发送邮件类（SendMail）

MailBean.java


package test3;




import java.util.Vector;




public class MailBean {




private String to; // 收件人


private String from; // 发件人


private String host; // SMTP主机


private String username; // 发件人的用户名


private String password; // 发件人的密码


private String subject; // 邮件主题


private String content; // 邮件正文


Vector<String> file; // 多个附件


private String filename; // 附件的文件名




public String getTo() {


return to;


}




public void setTo(String to) {


this.to = to;


}




public String getFrom() {


return from;


}




public void setFrom(String from) {


this.from = from;


}




public String getHost() {


return host;


}




public void setHost(String host) {


this.host = host;


}




public String getUsername() {


return username;


}




public void setUsername(String username) {


this.username = username;


}




public String getPassword() {


return password;


}




public void setPassword(String password) {


this.password = password;


}




public String getSubject() {


return subject;


}




public void setSubject(String subject) {


this.subject = subject;


}




public String getContent() {


return content;


}




public void setContent(String content) {


this.content = content;


}




public String getFilename() {


return filename;


}




public void setFilename(String filename) {


this.filename = filename;


}




public Vector<String> getFile(){


return file;


}




public void attachFile(String fileName) {


if(file == null)


file = new Vector<String>();


file.addElement(fileName);


}


}



SendMail.java


package test3;




import java.util.Date;


import java.util.Enumeration;


import java.util.Properties;


import java.util.Vector;




import javax.activation.DataHandler;


import javax.activation.FileDataSource;


import javax.mail.Authenticator;


import javax.mail.Message;


import javax.mail.MessagingException;


import javax.mail.Multipart;


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 javax.mail.internet.MimeUtility;




public class SendMail {




public String toChinese(String text) {


try {


text = MimeUtility.encodeText(new String(text.getBytes(), "GB2312"), "GB2312", "B");


} catch (Exception e) {


e.printStackTrace();


}


return text;


}






public boolean sendMail(MailBean mb) {


String host = mb.getHost();


final String username = mb.getUsername();


final String password = mb.getPassword();


String from = mb.getFrom();


String to = mb.getTo();


String subject = mb.getSubject();


String content = mb.getContent();


String fileName = mb.getFilename();


Vector<String> file = mb.getFile();






Properties props = System.getProperties();


props.put("mail.smtp.host", host); // 设置SMTP的主机


props.put("mail.smtp.auth", "true"); // 需要经过验证




Session session = Session.getInstance(props, new Authenticator() {


public PasswordAuthentication getPasswordAuthentication() {


return new PasswordAuthentication(username, password);


}


});




try {


MimeMessage msg = new MimeMessage(session);


msg.setFrom(new InternetAddress(from));


InternetAddress[] address = {new InternetAddress(to)};


msg.setRecipients(Message.RecipientType.TO, address);


msg.setSubject(toChinese(subject));




Multipart mp = new MimeMultipart();


MimeBodyPart mbpContent = new MimeBodyPart();


mbpContent.setText(content);


mp.addBodyPart(mbpContent);




/* 往邮件中添加附件 */


Enumeration<String> efile = file.elements();


while (efile.hasMoreElements()) {


MimeBodyPart mbpFile = new MimeBodyPart();


fileName = efile.nextElement().toString();


FileDataSource fds = new FileDataSource(fileName);


mbpFile.setDataHandler(new DataHandler(fds));


mbpFile.setFileName(toChinese(fds.getName()));


mp.addBodyPart(mbpFile);


}




msg.setContent(mp);


msg.setSentDate(new Date());


Transport.send(msg);




} catch (MessagingException me) {


me.printStackTrace();


return false;


}


return true;


}




}





TestJavaMail.java


package test3;




public class TestJavaMail {




public static void main(String[] args) {




MailBean mb = new MailBean();


mb.setHost("smtp.163.com"); // 设置SMTP主机(163)，若用126，则设为：smtp.126.com


mb.setUsername("linyiteng1220"); // 设置发件人邮箱的用户名


mb.setPassword("******"); // 设置发件人邮箱的密码，需将*号改成正确的密码


mb.setFrom("linyiteng1220@163.com"); // 设置发件人的邮箱


mb.setTo("linyiteng1220@126.com"); // 设置收件人的邮箱


mb.setSubject("测试_JavaMail"); // 设置邮件的主题


mb.setContent("本邮件中包含三个附件，请检查！"); // 设置邮件的正文




mb.attachFile("E:/工作报告(林乙腾).doc"); // 往邮件中添加附件


mb.attachFile("E:/test.txt");


mb.attachFile("E:/test.xls");




SendMail sm = new SendMail();


System.out.println("正在发送邮件...");




if(sm.sendMail(mb)) // 发送邮件


System.out.println("发送成功!");


else


System.out.println("发送失败!");


}




}



如果你用myEclipse进行开发的话，运行时可能会出现以下的错误：

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/mail/util/LineInputStream

解决方法：移除myEclipse自带的EE包

。

但你可能还需要用到EE包里的servlet相关类，那可以从Tomcat的lib文件夹中复制servlet-api.jar到project中，用它来代替EE包，一切OK！

另外，个人测试时发现无法通过新注册的网易邮箱来发邮件，以前旧的就没有问题，不知道是什么原因。

如果要通过gmail发邮件的话，请在代码Properties props = System.getProperties();后再添加以下两行代码：

props.put("mail.transport.protocol", "smtp");

props.put("mail.smtp.starttls.enable","true");

搞定！

如果存在缺漏和问题，请大家指正！