java编写简单的E-mail发送端程序

// 邮件
class E_Mail {
 String from;
 String to;
 String subject;
 String content;
 String userName;
 String pwd;

 public E_Mail(String from, String to, String subject, 
 String content, String userName, String pwd) {
 this.from = from;
 this.to = to;
 this.subject = subject;
 this.content = content;
 this.userName = this.toBASE64(userName);
 this.pwd = this.toBASE64(pwd);
 }
 
 /**
 * 在 E_Mail 类中进行用户名、密码的转码工作
 */
 private String toBASE64(String str) {
 return (new sun.misc.BASE64Encoder().encode(str.getBytes())); 
 }
}
// 简单的邮件发送端类，实现发送功能
public class SimpleMailSender {
 private String smtpServer;
 private int port = 25;

 private Socket socket;
 BufferedReader br;
 PrintWriter pw;
 
 /**
 * 根据发件人的邮箱地址确定SMTP邮件服务器 
 */
 private void initServer(String from) {
 if(from.contains("@163")) {
 this.smtpServer = "smtp.163.com";
 }else if(from.contains("@126")) {
 this.smtpServer = "smtp.126.com";
 }else if(from.contains("@sina")) {
 this.smtpServer = "smtp.sina.com";
 }else if(from.contains("@qq")) {
 this.smtpServer = "smtp.qq.com";
 }
 }

 public void sendEmail(E_Mail email) {
 try {
 this.initServer(email.from);
 
 this.socket = new Socket(smtpServer, port);
 this.br = this.getReader(socket);
 this.pw = this.getWriter(socket);
 
 // 开始组装发送邮件的命令序列
 send_Receive(null); // 接收连接SMTP服务器成功的信息
 send_Receive("ehlo hao");
 send_Receive("auth login");
 send_Receive(email.userName);
 send_Receive(email.pwd);
 send_Receive("mail from:<" + email.from + ">");
 send_Receive("rcpt to:<" + email.to + ">");
 send_Receive("data");
 
 // 邮件内容
 pw.println("from:" + email.from);
 pw.println("to:" + email.to);
 // 主题与正文之间一定要空一行，即加上"\r\n"
 pw.println("subject:" + email.subject + "\r\n");
 
 // 在控制台打印邮件内容
 System.out.println("from:" + email.from);
 System.out.println("to:" + email.to); 
 System.out.println("subject:" + email.subject + "\r\n");
 System.out.println(email.content);
 
 // 邮件正文
 pw.println(email.content);
 
 // 一定记得正文以"."结束
 send_Receive(".");
 send_Receive("quit");
 } catch (IOException e) {
 e.printStackTrace();
 } finally {
 try {
 if (socket != null)
  socket.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 }
 
 /**
 * 每发送一条命令，必须在命令后面加上"\r\n",
 * 则同时打印出smtp邮件服务器的相应状态码
 * @param command
 */
 private void send_Receive(String command) throws IOException{
 if(command != null) {
 // 向SMTP邮件服务器发送命令，一定要记得加上"\r\n"
 pw.print(command + "\r\n");
 pw.flush();
 System.out.println("用户 >> " + command);
 }
 
 char [] response = new char[1024];
 br.read(response);
 System.out.println(response);
 }

 /**
 * 获取 Socket 的输出流
 */
 private PrintWriter getWriter(Socket socket) throws IOException {
 OutputStream socketOut = socket.getOutputStream();
 return new PrintWriter(socketOut, true);
 }

 /**
 * 获取 Socket 的输入流
 */
 private BufferedReader getReader(Socket socket) throws IOException {
 InputStream socketIn = socket.getInputStream();
 return new BufferedReader(new InputStreamReader(socketIn));
 }

 // 测试
 public static void main(String[] args) {
 new MailSenderGUI();
 }
}
// 邮件发送程序界面
class MailSenderGUI extends JFrame implements ActionListener {
 private JLabel userNameLabel;
 private JTextField userNameField;
 private JLabel pwdLabel;
 private JPasswordField pwdField;
 private JLabel fromLabel;
 private JTextField fromField;
 private JLabel toLabel;
 private JTextField toField;
 private JLabel subjectLabel;
 private JTextField subjectField;
 private JLabel contentLabel;
 private JTextArea contentArea;

 private JButton sendBtn;
 private JButton cancelBtn;

 private E_Mail email;

 private SimpleMailSender mailSender;

 public MailSenderGUI() {
 this.init();
 this.mailSender = new SimpleMailSender();
 }

 private void init() {
 this.fromLabel = new JLabel("发件人邮箱地址：");
 this.fromField = new JTextField(25);
 this.userNameLabel = new JLabel("用户名：");
 this.userNameField = new JTextField(25);
 this.pwdLabel = new JLabel("密码：");
 this.pwdField = new JPasswordField(25);
 this.toLabel = new JLabel("收件人邮箱地址：");
 this.toField = new JTextField(25);
 this.subjectLabel = new JLabel("邮件主题：");
 this.subjectField = new JTextField(20);
 this.contentLabel = new JLabel("邮件正文：");
 this.contentArea = new JTextArea(15, 20);

 this.setTitle("蚂蚁-->简单邮件发送器");
 this.setBounds(200, 30, 500, 500);
 this.setLayout(new BorderLayout());
 this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 this.setVisible(true);

 this.sendBtn = new JButton("发送");
 this.cancelBtn = new JButton("重置");

 this.sendBtn.addActionListener(this);
 this.cancelBtn.addActionListener(this);
 
 JPanel upPanel = new JPanel(new GridLayout(6, 2, 5, 5));
 upPanel.add(fromLabel);
 upPanel.add(fromField);
 upPanel.add(userNameLabel);
 upPanel.add(userNameField);
 upPanel.add(pwdLabel);
 upPanel.add(pwdField);
 upPanel.add(toLabel);
 upPanel.add(toField);
 upPanel.add(subjectLabel);
 upPanel.add(subjectField);
 upPanel.add(contentLabel);
 
 this.add(upPanel, BorderLayout.NORTH); 
 this.add(contentArea, BorderLayout.CENTER);
 
 JPanel downPanel = new JPanel(new FlowLayout(FlowLayout.CENTER));
 downPanel.add(sendBtn, BorderLayout.SOUTH);
 downPanel.add(cancelBtn, BorderLayout.SOUTH);
 
 this.add(downPanel, BorderLayout.SOUTH);
 }

 @Override
 public void actionPerformed(ActionEvent e) {
 if (e.getSource() == this.sendBtn) {
 this.email = new E_Mail(
  this.fromField.getText(),
  this.toField.getText(), 
  this.subjectField.getText(),
  this.contentArea.getText(),
  this.userNameField.getText(),
  new String(this.pwdField.getPassword())
  );

 this.mailSender.sendEmail(this.email);

 } else if (e.getSource() == this.cancelBtn) {
 this.fromField.setText(null);
 this.toField.setText(null);
 this.subjectField.setText(null);
 this.contentArea.setText(null);
 }

 }
}