实验七 应用层网络编程一

..大学城市学院实验报告课程名称计算机网络应用实验工程名称实验七应用层网络编程〔一〕实验成绩指导教师〔签名〕日期2014-06-03一.实验目的和要求通过实现使用Java应用层客户端和效劳器来获得关于使用JavaSocket网络编程的经历〔SMTP、POP3〕。二.实验容、原理及实验结果与分析SMTP编程〔参考电子讲义"网络编程参考资料-应用层.pdf〞及教材"第2章Socket编程〞〕阅读"网络编程参考资料-应用层.pdf〞中8.3.1局部，实现"SMTP客户机实现〞的源代码〔SMTPClientDemo.java〕，并在机器上编译运行通过。〔注：可输入城院SMTP效劳器.或其他效劳器作为SMTP效劳器〕【程序源代码】SMTPClientDemo.javaimportjava.io.*;import.*;importjava.util.*;//Chapter8,Listing1publicclassSMTPClientDemo{protectedintport=25;protectedStringhostname="localhost";protectedStringfrom="";protectedStringto="";protectedStringsubject="";protectedStringbody="";protectedSocketsocket;protectedBufferedReaderbr;protectedPrintWriterpw;//ConstructsanewinstanceoftheSMTPClientpublicSMTPClientDemo()throwsException{try{getInput();sendEmail();}catch(Exceptione){System.out.println("Errorsendingmessage-"+e);}}publicstaticvoidmain(String[]args)throwsException{ //StarttheSMTPclient,soitcansendmessages SMTPClientDemoclient=newSMTPClientDemo();}//ChecktheSMTPresponsecodeforanerrormessageprotectedintreadResponseCode()throwsException{Stringline=br.readLine();System.out.println("<"+line);line=line.substring(0,line.indexOf(""));returnInteger.parseInt(line);}//WriteaprotocolmessagebothtothenetworksocketandtothescreenprotectedvoidwriteMsg(Stringmsg)throwsException{pw.println(msg);pw.flush();System.out.println(">"+msg);}//Closeallreaders,streamsandsocketsprotectedvoidcloseConnection()throwsException{pw.flush();pw.close();br.close();socket.close();}//SendtheQUITprotocolmessage,andterminateconnectionprotectedvoidsendQuit()throwsException{System.out.println("SendingQUIT");writeMsg("QUIT");readResponseCode();System.out.println("ClosingConnection");closeConnection();}//SendanemailmessageviaSMTP,adheringtotheprotocolknownasRFC2821protectedvoidsendEmail()throwsException{System.out.println("Sendingmessagenow:Debugbelow");System.out.println("---------------------------------"+"-----------------------------");System.out.println("OpeningSocket");socket=newSocket(this.hostname,this.port);System.out.println("CreatingReader&Writer");br=newBufferedReader(newInputStreamReader(socket.getInputStream()));pw=newPrintWriter(newOutputStreamWriter(socket.getOutputStream()));System.out.println("Readingfirstline");intcode=readResponseCode();if(code!=220){socket.close();thrownewException("InvalidSMTPServer");}System.out.println("Sendinghelomand");writeMsg("HELO"+InetAddress.getLocalHost().getHostName());code=readResponseCode();if(code!=250){sendQuit();thrownewException("InvalidSMTPServer");}System.out.println("Sendingmailfrommand");writeMsg("MAILFROM:<"+this.from+">");code=readResponseCode();if(code!=250){sendQuit();thrownewException("Invalidfromaddress");}System.out.println("Sendingrcpttomand");writeMsg("RCPTTO:<"+this.to+">");code=readResponseCode();if(code!=250){sendQuit();thrownewException("Invalidtoaddress");}System.out.println("Sendingdatamand");writeMsg("DATA");code=readResponseCode();if(code!=354){sendQuit();thrownewException("Dataentrynotaccepted");}System.out.println("Sendingmessage");writeMsg("Subject:"+this.subject);writeMsg("To:"+this.to);writeMsg("From:"+this.from);writeMsg("");writeMsg(body);code=readResponseCode();sendQuit();if(code!=250)thrownewException("Messagemaynothavebeensentcorrectly");elseSystem.out.println("Messagesent");}//ObtaininputfromtheuserprotectedvoidgetInput()throwsException{//ReadinputfromuserconsoleStringdata=null;BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));//RequesthostnameforSMTPserverSystem.out.print("PleaseenterSMTPserverhostname:");data=br.readLine();if(data==null||data.equals(""))hostname="localhost";elsehostname=data;//Requestthesender'semailaddressSystem.out.print("PleaseenterFROMemailaddress:");data=br.readLine();from=data;//Requesttherecipient'semailaddressSystem.out.print("PleaseenterTOemailaddress:");data=br.readLine();if(!(data==null||data.equals("")))to=data;System.out.print("Pleaseentersubject:");data=br.readLine();subject=data;System.out.println("Pleaseenterplain-textmessage('.'character"+"onablanklinesignalsendofmessage):");StringBufferbuffer=newStringBuffer();//Readuntiluserentersa.onablanklineStringline=br.readLine();while(line!=null){//Checkfora'.',andonlya'.',onalineif(line.equalsIgnoreCase(".")){break;}buffer.append(line);buffer.append("\n");line=br.readLine();}buffer.append(".\n");body=buffer.toString();}}【实验结果与分析】POP3编程〔参考电子讲义"网络编程参考资料-应用层.pdf〞及教材"第2章Socket编程〞〕阅读"网络编程参考资料-应用层.pdf〞中8.3.2局部，实现"POP3客户实现〞的源代码〔Pop3ClientDemo.java〕，并在机器上编译运行通过。〔注：可输入城院POP3效劳器.或其他效劳器作为POP3效劳器〕【程序源代码】Pop3ClientDemo.javaimportjava.io.*;import.*;importjava.util.*;publicclassPop3ClientDemo{protectedintport=110;protectedStringhostname="localhost";protectedStringusername="";protectedStringpassword="";protectedSocketsocket;protectedBufferedReaderbr;protectedPrintWriterpw;//ConstructsanewinstanceofthePOP3clientpublicPop3ClientDemo()throwsException{try{//GetuserinputgetInput();//GetmailmessagesdisplayEmails();}catch(Exceptione){System.err.println("Erroroccured-detailsfollow");e.printStackTrace();System.out.println(e.getMessage());}}//ReturnsTRUEifPOPresponseindicatessuccess,FALSEiffailureprotectedbooleanresponseIsOk()throwsException{Stringline=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。returnline.toUpperCase().startsWith("+OK");}//ReadsalinefromthePOPserver,anddisplaysittoscreenprotectedStringreadLine(booleandebug)throwsException{Stringline=br.readLine();//Appenda<charactertoindicatethisisaserverprotocolresponseif(debug)System.out.println("<"+line);elseSystem.out.println(line);returnline;}//WritesalinetothePOPserver,anddisplaysittothescreenprotectedvoidwriteMsg(Stringmsg)throwsException{pw.println(msg);pw.flush();System.out.println(">"+msg);}//Closeallwriters,streamsandsocketsprotectedvoidcloseConnection()throwsException{pw.flush();pw.close();br.close();socket.close();}//SendtheQUITmand,andcloseconnectionprotectedvoidsendQuit()throwsException{System.out.println("SendingQUIT");writeMsg("QUIT");readLine(true);System.out.println("ClosingConnection");closeConnection();}//DisplayemailsinamessageprotectedvoiddisplayEmails()throwsException{BufferedReaderuserinput=newBufferedReader(newInputStreamReader(System.in));System.out.println("Displayingmailboxwithprotocolmands"+"andresponsesbelow");System.out.println("-----------------------------------------"+"---------------------");//OpenaconnectiontoPOP3serverSystem.out.println("OpeningSocket");socket=newSocket(this.hostname,this.port);br=newBufferedReader(newInputStreamReader(socket.getInputStream()));pw=newPrintWriter(newOutputStreamWriter(socket.getOutputStream()));//Ifresponsefromserverisnotokayif(!responseIsOk()){socket.close();thrownewException("InvalidPOP3Server");}//LoginbysendingUSERandPASSmandsSystem.out.println("Sendingusername");writeMsg("USER"+this.username);if(!responseIsOk()){sendQuit();thrownewException("Invalidusername");}System.out.println("Sendingpassword");writeMsg("PASS"+this.password);if(!responseIsOk()){sendQuit();thrownewException("Invalidpassword");}//Getmailcountfromserver....System.out.println("Checkingmail");writeMsg("STAT");//...andparsefornumberofmessagesStringline=readLine(true);StringTokenizertokens=newStringTokenizer(line,"");//+OKtokens.nextToken();//numberofmessagesintmessages=Integer.parseInt(tokens.nextToken());//sizeofallmessagesintmaxsize=Integer.parseInt(tokens.nextToken());if(messages==0){System.out.println("Therearenomessages.");sendQuit();return;}System.out.println("Thereare"+messages+"messages.");System.out.println("Pressentertocontinue.");userinput.readLine();for(inti=1;i<=messages;i++){System.out.println("Retrievingmessagenumber"+i);writeMsg("RETR"+i);System.out.println("--------------------");line=readLine(false);while(line!=null&&!line.equals(".")){line=readLine(false);}System.out.println("--------------------");System.out.println("Pressentertocontinue.Tostop,"+"typeQthenenter");Stringresponse=userinput.readLine();if(response.toUpperCase().startsWith("Q"))break;}sendQuit();}publicstaticvoidmain(String[]args)throwsException{Pop3ClientDemoclient=newPop3ClientDemo();}//ReaduserinputprotectedvoidgetInput()throwsException{Stringdata=null;BufferedReaderbr=newBufferedReader(newInputStreamReader(System.in));System.out.p