實(shí)驗(yàn)七--應(yīng)用層網(wǎng)絡(luò)編程(一)

1、浙江大學(xué)城市學(xué)院實(shí)驗(yàn)報(bào)告課程名稱實(shí)驗(yàn)項(xiàng)目名稱實(shí)驗(yàn)成績實(shí)驗(yàn)七指導(dǎo)老師（簽名）計(jì)算機(jī)網(wǎng)絡(luò)應(yīng)用應(yīng)用層網(wǎng)絡(luò)編程（一）日期2014-06-03一 . 實(shí)驗(yàn)?zāi)康暮鸵?.通過實(shí)現(xiàn)使用 Java 應(yīng)用層客戶端和服務(wù)器來獲得關(guān)于使用 Java Socket 網(wǎng)絡(luò)編程的經(jīng)驗(yàn)（ SMTP、POP3）。二 . 實(shí)驗(yàn)內(nèi)容、原理及實(shí)驗(yàn)結(jié)果與分析1. SMTP 編程（參考電子講義 “網(wǎng)絡(luò)編程參考資料 -應(yīng)用層 .pdf ”及教材“第2 章 Socket 編程”）閱讀 “網(wǎng)絡(luò)編程參考資料 -應(yīng)用層 .pdf ”中 8.3.1 部分，實(shí)現(xiàn)“ SMTP 客戶機(jī)實(shí)現(xiàn)”的源代碼（ SMTPClientDemo.java ），并在機(jī)

2、器上編譯運(yùn)行通過。（注：可輸入城院 SMTP 郵件服務(wù)器 或其他郵件服務(wù)器作為 SMTP 服務(wù)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(shí)驗(yàn)結(jié)果與分析】2. POP3 編程（參考電子講義 “網(wǎng)絡(luò)編程參考資料 -應(yīng)用層 .pdf ”及教材“第2 章 Socket編程”）閱讀 “網(wǎng)絡(luò)編程參考資料 -應(yīng)用層 .pdf ”中 8.3.2 部分，實(shí)現(xiàn)“ POP3 客戶實(shí)現(xiàn)”的源代碼（ Pop3ClientDemo.java ），并在機(jī)器上編譯運(yùn)行通過。（注：可輸入城院 POP3 郵件服務(wù)器 或其他郵件服務(wù)

16、器作為 POP3 服務(wù)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(gè)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