ftp服務檢測

 1.直接的socket連接,改自openNMS,參考ftp://ftp.rfc-editor.org/in-notes/std/std9.txt

        int retry = 2;
        int port = 21;
        int timeout = 3000;
        String userid = "test";
        String password = "test";
        InetAddress ipv4Addr = null;
        try ...{
            ipv4Addr = InetAddress.getByName("192.168.7.61");
        } catch (UnknownHostException e1) ...{
            e1.printStackTrace();
        }

        int serviceStatus = 1;
        long responseTime = -1;
        for (int attempts = 0; attempts <= retry && serviceStatus == 1; attempts++) ...{
            Socket socket = null;
            try ...{
                // create a connected socket
                long sentTime = System.currentTimeMillis();

                socket = new Socket();
                socket.connect(new InetSocketAddress(ipv4Addr, port), timeout);
                socket.setSoTimeout(timeout);

                // We're connected, so upgrade status to unresponsive
                serviceStatus = -1;

                BufferedReader lineRdr = new BufferedReader(
                        new InputStreamReader(socket.getInputStream()));

                // Tokenize the Banner Line, and check the first
                // line for a valid return.
                responseTime = System.currentTimeMillis() - sentTime;
                String banner = lineRdr.readLine();
                System.out.println("banner=" + banner);
                StringTokenizer t = new StringTokenizer(banner);

                int rc = -1;
                try ...{
                    rc = Integer.parseInt(t.nextToken());
                } catch (NumberFormatException nfE) ...{
                    nfE.fillInStackTrace();
                }

                // Verify that return code is in proper range.
                if (rc >= 200 && rc <= 299) ...{
                    // Attempt to login if userid and password available
                    boolean bLoginOk = false;
                    if (userid == null || userid.length() == 0
                            || password == null || password.length() == 0) ...{
                        bLoginOk = true;
                    } else ...{
                        // send the use string
                        String cmd = "user " + userid + " ";
                        socket.getOutputStream().write(cmd.getBytes());
                        // get the response code.
                        String response = null;
                        response = lineRdr.readLine();
                        System.out.println("response=" + response);
                        t = new StringTokenizer(response);
                        rc = Integer.parseInt(t.nextToken());

                        // Verify that return code is in proper range.
                        if (rc >= 200 && rc <= 399) ...{
                            // send the password
                            cmd = "pass " + password + " ";
                            socket.getOutputStream().write(cmd.getBytes());

                            // get the response...check for multi-line response
                            response = lineRdr.readLine();
                            if (response == null)
                                continue;

                            // Verify that return code is in proper range.
                            System.out.println("FtpMonitor.poll: tokenizing respone to check for return code: "+ response);
                            t = new StringTokenizer(response);
                            rc = Integer.parseInt(t.nextToken());
                            if (rc >= 200 && rc <= 299) ...{
                                System.out.println("FtpMonitor.poll: Login successful, parsed return code: "+ rc);
                                bLoginOk = true;
                            } else ...{
                                System.out.println("FtpMonitor.poll: Login failed, parsed return code: "+ rc);
                                bLoginOk = false;
                            }
                        }
                    }

                    if (bLoginOk) ...{
                        // FTP should recognize the QUIT command
                        String cmd = "QUIT ";
                        socket.getOutputStream().write(cmd.getBytes());

                        // get the returned string, tokenize, and
                        // verify the correct output.
                        String response = lineRdr.readLine();

                        t = new StringTokenizer(response);
                        rc = Integer.parseInt(t.nextToken());

                        // Verify that return code is in proper range.
                        System.out.println("rc==" + rc);
                        serviceStatus = 1;
                    }
                }

                // If we get this far and the status has not been set
                // to available, then something didn't verify during
                // the banner checking or login/QUIT command process.
                if (serviceStatus == 1) ...{
                    serviceStatus = -1;
                }

            } catch (Exception e) ...{
                e.printStackTrace();
            }
        }

2.運用開發包API,edtftpj-1.5.3, http://www.enterprisedt.com

        FTPClient ftp = new FTPClient();
        try ...{
            ftp.setRemoteHost("192.168.7.61");
            ftp.setRemotePort(21);
            ftp.setConnectMode(FTPConnectMode.ACTIVE);
            ftp.connect();
            ftp.login("test", "test");
        } catch (Exception e) ...{
            System.out.println("connect error");
            e.printStackTrace();
        } finally ...{
            if (ftp != null)
                try ...{
                    ftp.quit();
                } catch (Exception e) ...{
                    System.out.println("quit error");
                    e.printStackTrace();
                }
        }