Java——简单邮件发送客户端实现

这个程序主要就是实现一个简单的邮件客户端，在知道邮箱服务器pop3地址的情况下可以实现随意填写发信人地址给指定用户发邮件。

代码如下：importjava.awt.*;importjava.awt.event.*;import java.io.*;import .*;importjavax.swing.*;importjavax.swing.border.BevelBorder;public class Mailclient extends JFrame {publicMailclient() {JPanel p = new JPanel();//create the GUIJPanel p1 = new JPanel();JPanel p2 = new JPanel();JPanel p3 = new JPanel();JPanel p4 = new JPanel();JPanel p5 = new JPanel();JButton Send = new JButton("Send");//three buttonJButton Clear = new JButton("Clear");JButton Quit = new JButton("Quit");String defult = "You can change the information or use the defult, and you can get the run information from Java Console.";//create the default mail textfinalJTextArea messages = new JTextArea(defult, 22, 40);messages.setLineWrap(true);//auto line feedmessages.setBorder(new BevelBorder(BevelBorder.LOWERED, Color.gray, Color.gray));p1.add(new JLabel("From: "));finalJTextField jtf1 = new JTextField("android_757@", 38);p1.add(jtf1);p2.add(new JLabel("To: "));finalJTextField jtf2 = new JTextField("android_757@", 40);p2.add(jtf2);p3.add(new JLabel("Subject: "));finalJTextField jtf3 = new JTextField("Test Mailclient", 37);p3.add(jtf3);p5.add(new JLabel("Mail Server Name: "));finalJTextField jtf4 = new JTextField("", 32);p5.add(jtf4);p4.add(Send);Send.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e){Socket clientSocket;OutputStreamoutToServer;//send messengers to mail serverBufferedReaderinFromServer;//receive messengers from mail serverString mailFrom = jtf1.getText();//get the information that user inputString mailTo = jtf2.getText();String mailSubject = jtf3.getText();String mailSeverName = jtf4.getText();String getFromServer = null;try {clientSocket = new Socket(mailSeverName, 25);//create connect with mailServer on port 25inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));outToServer = clientSocket.getOutputStream();PrintWritersockout = new PrintWriter (outToServer, true);getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("220")){//send messengers as STMP rules(book page 78)sockout.println ("HELO Sariel"); //and output all information on consoleSystem.out.println("HELO Sariel");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("250")){sockout.println ("MAIL FROM: " +"<" + mailFrom + ">");System.out.println("MAIL FROM: " +"<" + mailFrom + ">");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("250")){sockout.println ("RCPT TO: " +"<" + mailTo + ">");System.out.println("RCPT TO: " +"<" + mailTo + ">");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("250")){sockout.println ("DATA");System.out.println("DATA");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("354")){sockout.println ("From: " + mailFrom);sockout.println ("To: " + mailTo);sockout.println ("Subject: " + mailSubject);sockout.println ();System.out.println("From: " + mailFrom);System.out.println("To: " + mailTo);System.out.println("Subject: " + mailSubject);System.out.println();String str=messages.getText();StringReadersr=new StringReader(str);BufferedReaderbr=new BufferedReader(sr);String line = "";while(true){try {//write the main text to serverline=br.readLine();if(line == null)break;sockout.println (line);System.out.println(line);} catch (IOException e1) {e1.printStackTrace();}}sockout.println (".");//end main text with "."System.out.println(".");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("250")){sockout.println ("QUIT");System.out.println("QUIT");getFromServer = inFromServer.readLine();System.out.println(getFromServer);if(getFromServer.startsWith("221")){System.out.println('\n' + "Successfully send!!!");}}}}}}}} catch (UnknownHostException e2) {e2.printStackTrace();} catch (IOException e2) {e2.printStackTrace();}}});p4.add(Clear);//the button "Clear" delete all information in JTextAreaClear.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e){messages.setText("");}});p4.add(Quit);Quit.addActionListener(new ActionListener() {public void actionPerformed(ActionEvent e){System.exit(0);}});p.add(p1);p.add(p2);p.add(p3);p.add(p5);p.add(messages);p.add(p4);p.setBorder(new BevelBorder(BevelBorder.RAISED));add(p);}public static void main(String[] args){JFramemailclient = new Mailclient();mailclient.setTitle("Java Mailclient");mailclient.setLocationRelativeTo(null);mailclient.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);mailclient.setSize(500, 640);mailclient.setVisible(true);}};。