FTP协议Java实现

我不是女神ヾ 2022-12-01 12:23 172阅读 0赞

FTP协议Java实现

参照文章 [https://blog.csdn.net/qq\_16038125/article/details/72851142][https_blog.csdn.net_qq_16038125_article_details_72851142] 讲的原理

具体实现参考

<dependency>
        <groupId>commons-net</groupId>
        <artifactId>commons-net</artifactId>
        <version>3.6</version>
    </dependency>

搭建ftp命令

# 安装vsftpd
    sudo apt-get install vsftpd
    vsftpd -version
    # 新建ftp目录
    mkdir /home/ftp
    # 新增用户
    sudo useradd -d /home/ftp -s /bin/bash ftpname
    passwd ftpname
    # 修改配置
    vi /etc/vsftpd.conf
    # 修改配置-找到这个配置，去掉注释修改成YES
    userlist_enable=YES
    # 启动服务
    service vsftpd start

被动模式实现

import javax.net.SocketFactory;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.InetSocketAddress;
    import java.net.Socket;
    import java.util.Arrays;
    import java.util.regex.Matcher;
    import java.util.regex.Pattern;
    
    /**
     * 被动模式的FTP
     */
    public class FtpPassiveTest {
    
        public static void main(String[] args) throws IOException {
            SocketFactory socketFactory = SocketFactory.getDefault();
            Socket socket = socketFactory.createSocket();
            socket.connect(new InetSocketAddress("192.168.72.132", 21), 10000);
            socket.setSoTimeout(10000);
            InputStream inputStream = socket.getInputStream();
            OutputStream outputStream = socket.getOutputStream();
    
            // 预读取
            read(inputStream);
    
            // 发送命令
            outputStream.write("USER ftpname\r\n".getBytes());outputStream.flush();
            read(inputStream);
            outputStream.write("PASS 123456\r\n".getBytes());outputStream.flush();
            read(inputStream);
    
            outputStream.write("PASV\r\n".getBytes());outputStream.flush();
            String passiveMode = read(inputStream);
            Pattern parmsPat = Pattern.compile("(\\d{1,3},\\d{1,3},\\d{1,3},\\d{1,3}),(\\d{1,3}),(\\d{1,3})");
            Matcher matcher = parmsPat.matcher(passiveMode);
            matcher.find();
            String replace = matcher.group(1).replace(',', '.');
    
            int oct1 = Integer.parseInt(matcher.group(2));
            int oct2 = Integer.parseInt(matcher.group(3));
            int passivePort = (oct1 << 8) | oct2;
    
            System.out.println(replace + "  " + passivePort);
            Socket lsSocket = socketFactory.createSocket();
            lsSocket.connect(new InetSocketAddress(replace, passivePort));
    
            outputStream.write("LIST\r\n".getBytes());
            outputStream.flush();
            read(inputStream);
    
            read2(lsSocket.getInputStream());
        }
    
        public static String read(InputStream inputStream) throws IOException {
            byte[] buffer = new byte[10240];
            int read = inputStream.read(buffer);
            String result = new String(Arrays.copyOfRange(buffer, 0, read));
            System.out.println(result);
            return result;
        }
    
        public static String read2(InputStream inputStream) throws IOException {
            byte[] buffer = new byte[200];
            int read = inputStream.read(buffer);
            String result = new String(Arrays.copyOfRange(buffer, 100, read));
            System.out.println(result);
            return result;
        }
    
    }

主动模式实现

import javax.net.ServerSocketFactory;
    import javax.net.SocketFactory;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.net.InetSocketAddress;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.util.Arrays;
    
    /**
     * 主动模式的FTP
     */
    public class FtpActiveTest {
    
        public static void main(String[] args) throws IOException {
            SocketFactory socketFactory = SocketFactory.getDefault();
            Socket socket = socketFactory.createSocket();
            socket.connect(new InetSocketAddress("192.168.72.132", 21), 10000);
            socket.setSoTimeout(10000);
            InputStream inputStream = socket.getInputStream();
            OutputStream outputStream = socket.getOutputStream();
    
            // 预读取
            read(inputStream);
    
            // 发送命令
            outputStream.write("USER ftpname\r\n".getBytes());outputStream.flush();
            read(inputStream);
            outputStream.write("PASS 123456\r\n".getBytes());outputStream.flush();
            read(inputStream);
    
            ServerSocketFactory serverSocketFactory = ServerSocketFactory.getDefault();
            ServerSocket serverSocket = serverSocketFactory.createServerSocket(0, 1, socket.getLocalAddress());
    
            // 告诉ftp服务器，我本地socket套接字是个啥
            String hostAddress = socket.getLocalAddress().getHostAddress();
            String port = port(hostAddress, serverSocket.getLocalPort());
            String cmd = "PORT " + port + "\r\n";
            outputStream.write(cmd.getBytes());outputStream.flush();
            read(inputStream);
            // 向ftp服务器发送列出列表指令
            outputStream.write("LIST /home/ftp\r\n".getBytes());outputStream.flush();
            read(inputStream);
    
            // 获取ftp服务器的套接字 并接受ftp服务器套接字的返回
            Socket accept = serverSocket.accept();
            read(accept.getInputStream());
            serverSocket.close();
        }
    
        public static String port(String hostAddress, int port) throws IOException
        {
            int num;
            StringBuilder info = new StringBuilder(24);
    
            info.append(hostAddress.replace('.', ','));
            num = port >>> 8;
            info.append(',');
            info.append(num);
            info.append(',');
            num = port & 0xff;
            info.append(num);
    
            return info.toString();
        }
    
        public static void read(InputStream inputStream) throws IOException {
            byte[] buffer = new byte[10240];
            int read = inputStream.read(buffer);
            String result = new String(Arrays.copyOfRange(buffer, 0, read));
            System.out.println(result);
        }
    
    }

[https_blog.csdn.net_qq_16038125_article_details_72851142]: https://blog.csdn.net/qq_16038125/article/details/72851142