Java2网络协议内幕　一书源码

// FTP LS import java.net.*; import java.io.*; public class FtpLS { final public static boolean debug=true; // true for debug trace protected Socket ctlskt; // control socket protected Socket datskt; // data socket protected Reader datReader; // IO Stream for data socket protected Writer datWriter; protected BufferedReader ctlin; // Control port reader protected OutputStream ctlout; // Control port writer public String lastResponse; // Last response from host public boolean passive = false; // passive mode // Connect to host -- we don't do ACCT public boolean connect(String host,String user, String pw) throws UnknownHostException, IOException { int status; ctlskt=new Socket(host,21); ctlin=new BufferedReader( new InputStreamReader(ctlskt.getInputStream())); ctlout=ctlskt.getOutputStream(); do { status=getResponse(); } while (status!=220 && status!=-1); if (status==-1) { return false; } status=sendCmd("USER " + user); if (status==331) status=sendCmd("PASS " + pw); if (status==332) return false; // no ACCT if (status!=230) return false; return true; } // This creates a data socket, issues a port command // and then pipes everything from the // data port to the specified writer (which could // be the console, or a string, or a file) protected int dataSocket(String datCmd) throws IOException { int port; int status; ServerSocket datsktsvr; if (passive) { java.util.StringTokenizer token; StringBuffer IP=new StringBuffer(); int i; status=sendCmd("PASV"); if (status<200||status>299) return -1; // find IP/port for (i=4;i<lastResponse.length();i++) if (Character.isDigit(lastResponse.charAt(i))) break; if (i==lastResponse.length()) return -1; // not found token=new java.util.StringTokenizer(lastResponse.substring(i),",) "); if (token.countTokens()!=6) return -1; // unknown IP/port for (i=0;i<4;i++) { IP.append(token.nextToken()); if (i!=3) IP.append("."); } port=Integer.parseInt(token.nextToken())*256; port+=Integer.parseInt(token.nextToken()); datskt=new Socket(IP.toString(),port); status=sendCmd(datCmd); } else { datsktsvr=new ServerSocket(0); port=datsktsvr.getLocalPort(); //set host/port StringBuffer cmd = new StringBuffer("PORT "); cmd.append(ctlskt.getLocalAddress().getHostAddress()); for (int i = 0; i < cmd.length(); i++) { if ('.' == cmd.charAt(i)) cmd.setCharAt(i, ','); } cmd.append(","); cmd.append(Integer.toString(port/256)); cmd.append(","); cmd.append(Integer.toString(port&0xFF)); status=sendCmd(cmd.toString()); if (status!=200) return -1; status=sendCmd(datCmd); // wait for remote connection (could time out) datskt=datsktsvr.accept(); } return 0; } public int dataSocketIn(String datCmd,Writer w) throws IOException { int status; status=dataSocket(datCmd); if (status!=0) return status; datReader=new InputStreamReader(datskt.getInputStream()); // transfer data until socket closes int ch; do { ch=datReader.read(); if (ch!=-1) w.write((char)ch); } while (ch!=-1); w.flush(); datskt.close(); return getResponse(); } public int dataSocketOut(String datCmd,Reader r) throws IOException { int status; status=dataSocket(datCmd); if (status!=0) return status; datWriter=new OutputStreamWriter(datskt.getOutputStream()); int ch; do { ch=r.read(); if (ch!=-1) datWriter.write((char)ch); } while (ch!=-1); datWriter.flush(); datskt.close(); return getResponse(); } // Get a response accounting for possible mutliline responses protected int getResponse() throws IOException { int n; String tmp; do { lastResponse=ctlin.readLine(); if (debug) System.out.println("DEBUG Received: " + lastResponse); } while (lastResponse.charAt(3)=='-'); tmp=lastResponse.substring(0,3); try { n=Integer.parseInt(tmp); } catch (NumberFormatException e) { n=-1; } return n; } // Send a command and return status code public int sendCmd(String cmd) throws IOException { if (debug) System.out.println("DEBUG Sent: " + cmd); String tmp=cmd+"\r\n"; int n; ctlout.write(tmp.getBytes()); ctlout.flush(); return getResponse(); } // Main driver public static void main(String [] args) throws Exception { if (args.length<3||args.length>4) { System.out.println("usage: EZftp host user password [directory]"); System.exit(1); } FtpLS obj= new FtpLS(); obj.passive=true; if (!obj.connect(args[0],args[1],args[2])) { System.out.println("Can't connect"); System.exit(1); } // Last argument is directory if present if (args.length==4) obj.sendCmd("CWD " + args[3]); // print directory (chop off response code) obj.sendCmd("PWD"); System.out.println(obj.lastResponse.substring(4)); // Do a directory obj.dataSocketIn("LIST",new OutputStreamWriter(System.out)); // Additional code FileWriter f = new FileWriter("ftp.test"); obj.dataSocketIn("RETR readme",f); System.out.println(obj.lastResponse); // Write test FileReader fw = new FileReader("ftp.test"); obj.dataSocketOut("STOR ftp.test",fw); System.out.println(obj.lastResponse); System.exit(0); } }