實驗七--應用層網(wǎng)絡編程(一)

1、浙江大學城市學院實驗報告課程名稱實驗項目名稱實驗成績實驗七指導老師（簽名）計算機網(wǎng)絡應用應用層網(wǎng)絡編程（一）日期2014-06-03一 . 實驗目的和要求1.通過實現(xiàn)使用 Java 應用層客戶端和服務器來獲得關(guān)于使用 Java Socket 網(wǎng)絡編程的經(jīng)驗（ SMTP、POP3）。二 . 實驗內(nèi)容、原理及實驗結(jié)果與分析1. SMTP 編程（參考電子講義 “網(wǎng)絡編程參考資料 -應用層 .pdf ”及教材“第2 章 Socket 編程”）閱讀 “網(wǎng)絡編程參考資料 -應用層 .pdf ”中 8.3.1 部分，實現(xiàn)“ SMTP 客戶機實現(xiàn)”的源代碼（ SMTPClientDemo.java ），并在機

2、器上編譯運行通過。（注：可輸入城院 SMTP 郵件服務器 或其他郵件服務器作為 SMTP 服務器）【程序源代碼】SMTPClientDemo.javaimport java.io.*;import .*;import java.util.*;/ Chapter 8, Listing 1public class SMTPClientDemo protected int port = 25;protected String hostname = localhost;protected String from = ;protected S

3、tring to = ;protected String subject = ;protected String body = ;protected Socket socket;protected BufferedReader br;protected PrintWriter pw;/ Constructs a new instance of the SMTP Clientpublic SMTPClientDemo() throws Exception try getInput();sendEmail(); catch (Exception e) System.out.println (Err

4、or sending message - + e);public static void main(String args) throws Exception / Start the SMTP client, so it can send messages SMTPClientDemo client = new SMTPClientDemo();/ Check the SMTP response code for an error message protected int readResponseCode() throws Exception String line = br.readLin

5、e(); System.out.println( +msg);/ Close all readers, streams and socketsprotected void closeConnection() throws Exception pw.flush();pw.close();br.close();socket.close();/ Send the QUIT protocol message, and terminate connection protected void sendQuit() throws Exception System.out.println(Sending QU

6、IT);writeMsg(QUIT);readResponseCode();System.out.println(Closing Connection);closeConnection();/ Send an email message via SMTP , adhering to the protocol known as RFC 2821protected void sendEmail() throws Exception System.out.println(Sending message now: Debug below);System.out.println(- +-);System

7、.out.println(Opening Socket);socket = new Socket(this.hostname,this.port);System.out.println(Creating Reader & Writer);br = new BufferedReader(new InputStreamReader(socket.getInputStream();pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream();System.out.println(Reading first line);int

8、 code = readResponseCode();if(code != 220) socket.close();throw new Exception(Invalid SMTP Server);System.out.println(Sending helo command);writeMsg(HELO +InetAddress.getLocalHost().getHostName(); code = readResponseCode();if(code != 250) sendQuit();throw new Exception(Invalid SMTP Server);System.ou

9、t.println(Sending mail from command);writeMsg(MAIL FROM:);code = readResponseCode();if(code != 250) sendQuit();throw new Exception(Invalid from address);System.out.println(Sending rcpt to command);writeMsg(RCPT TO:);code = readResponseCode();if(code != 250) sendQuit();throw new Exception(Invalid to

10、address);System.out.println(Sending data command);writeMsg(DATA);code = readResponseCode();if(code != 354) sendQuit();throw new Exception(Data entry not accepted);System.out.println(Sending message);writeMsg(Subject: +this.subject);writeMsg(To: +this.to);writeMsg(From: +this.from);writeMsg();writeMs

11、g(body);code = readResponseCode();sendQuit();if(code != 250)throw new Exception(Message may not have been sent correctly);elseSystem.out.println(Message sent);/ Obtain input from the userprotected void getInput() throws Exception / Read input from user console String data=null;BufferedReaderbr=newBu

12、fferedReader(newInputStreamReader(System.in);/ Request hostname for SMTP server System.out.print(Please enter SMTP server hostname: ); data = br.readLine();if (data = null | data.equals() hostname=localhost;else hostname=data;/ Request the senders email address System.out.print(Please enter FROM ema

13、il address: ); data = br.readLine();from = data;/ Request the recipients email address System.out.print(Please enter TO email address :); data = br.readLine();if(!(data = null | data.equals() to=data;System.out.print(Please enter subject: );data = br.readLine();subject=data;System.out.println(Please

14、 enter plain-text message (. character + on a blank line signals end of message):);StringBuffer buffer = new StringBuffer();/ Read until user enters a . on a blank line String line = br.readLine();while(line != null) / Check for a ., and only a ., on a line if(line.equalsIgnoreCase(.) break;buffer.a

15、ppend(line);buffer.append(n); line = br.readLine();buffer.append(.n);body = buffer.toString();【實驗結(jié)果與分析】2. POP3 編程（參考電子講義 “網(wǎng)絡編程參考資料 -應用層 .pdf ”及教材“第2 章 Socket編程”）閱讀 “網(wǎng)絡編程參考資料 -應用層 .pdf ”中 8.3.2 部分，實現(xiàn)“ POP3 客戶實現(xiàn)”的源代碼（ Pop3ClientDemo.java ），并在機器上編譯運行通過。（注：可輸入城院 POP3 郵件服務器 或其他郵件服務

16、器作為 POP3 服務器）【程序源代碼】Pop3ClientDemo.javaimport java.io.*;import .*;import java.util.*;public class Pop3ClientDemo protected int port = 110;protected String hostname = localhost;protected String username = ;protected String password = ;protected Socket socket;protected BufferedReader br;protec

17、ted PrintWriter pw;/ Constructs a new instance of the POP3 clientpublic Pop3ClientDemo() throws Exception try / Get user input getInput();/ Get mail messages displayEmails(); catch(Exception e) System.err.println (Error occured - details follow);e.printStackTrace();System.out.println(e.getMessage();

18、/ Returns TRUE if POP response indicates success, FALSE if failure protected boolean responseIsOk() throws Exception String line = br.readLine(); System.out.println( +line);/ 和 SMTP 不同的地方， POP3的回覆不再是一個number而是/ +OK 來代表要求成功。失敗則以 -ERR 來代表。 return line.toUpperCase().startsWith(+OK);/ Reads a line from

19、the POP server, and displays it to screen protected String readLine(boolean debug) throws Exception String line = br.readLine();/ Append a character to indicate this is a server protocol responseif (debug)System.out.println( +msg);/ Close all writers, streams and socketsprotected void closeConnectio

20、n() throws Exception pw.flush();pw.close();br.close();socket.close();/ Send the QUIT command, and close connection protected void sendQuit() throws Exception System.out.println(Sending QUIT);writeMsg(QUIT);readLine(true);System.out.println(Closing Connection);closeConnection();/ Display emails in a

21、messageprotected void displayEmails() throws Exception BufferedReader userinput = new BufferedReader( newInputStreamReader(System.in) );System.out.println(Displaying mailbox with protocol commands +and responses below);System.out.println(- +-);/ Open a connection to POP3 server System.out.println(Op

22、ening Socket); socket = new Socket(this.hostname, this.port);br = new BufferedReader(new InputStreamReader(socket.getInputStream();pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream();/ If response from server is not okayif(! responseIsOk() socket.close();throw new Exception(Invalid

23、POP3 Server);/ Login by sending USER and PASS commandsSystem.out.println(Sending username);writeMsg(USER +this.username);if(!responseIsOk() sendQuit();throw new Exception(Invalid username);System.out.println(Sending password);writeMsg(PASS +this.password);if(!responseIsOk() sendQuit();throw new Exce

24、ption(Invalid password);/ Get mail count from server .System.out.println(Checking mail); writeMsg(STAT);/ . and parse for number of messages String line = readLine(true);StringTokenizer tokens = new StringTokenizer(line, );/ +OKtokens.nextToken();/ number of messagesint messages = Integer.parseInt(t

25、okens.nextToken();/ size of all messagesint maxsize = Integer.parseInt(tokens.nextToken();if (messages = 0) System.out.println (There are no messages.);sendQuit();return;System.out.println (There are + messages + messages.); System.out.println(Press enter to continue.); userinput.readLine();for(int

26、i = 1; i = messages ; i+) System.out.println(Retrieving message number +i);writeMsg(RETR +i);System.out.println(-);line = readLine(false);while(line != null & !line.equals(.) line = readLine(false);System.out.println(-);System.out.println(Press enter to continue. To stop, + type Q then enter);String

27、 response = userinput.readLine();if (response.toUpperCase().startsWith(Q)break;sendQuit();public static void main(String args) throws Exception Pop3ClientDemo client = new Pop3ClientDemo();/ Read user inputprotected void getInput() throws Exception String data=null;BufferedReader br = new BufferedReader(new InputStreamReader(System.in);System.out.print(Please enter POP3 server hostname:); data = br.readLine();if(data = null | data.equals() hostname=localhost; else hostname=data;System.out.print(Please enter mailbox username:); data = br.readLine();if(!(dat