sshd - modric2jeff/archive GitHub Wiki

`import org.apache.sshd.client.SshClient; import org.apache.sshd.client.subsystem.sftp.SftpClient; import org.apache.sshd.client.subsystem.sftp.VirtualFileSystemFactory; import org.apache.sshd.common.file.virtualfs.VirtualFileSystemFactory;

import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.file.Paths;

public class SFTPFileDownloader {

public static void main(String[] args) {
    String host = "remote-server-ip";  // 远程服务器 IP 地址
    String user = "username";          // SSH 用户名
    String password = "password";      // SSH 密码
    String remoteFilePath = "/path/to/remote/logfile.log"; // 远程日志文件路径

    // 使用 Apache SSHd 连接到远程服务器并通过 SFTP 获取文件内容
    byte[] fileBytes = downloadFileAsBytes(host, user, password, remoteFilePath);

    // 输出文件的前 100 个字节（仅作为演示，实际应用中根据需要处理文件）
    if (fileBytes != null) {
        System.out.println("File downloaded, first 100 bytes: ");
        for (int i = 0; i < Math.min(100, fileBytes.length); i++) {
            System.out.print(fileBytes[i] + " ");
        }
    }
}

public static byte[] downloadFileAsBytes(String host, String user, String password, String remoteFilePath) {
    SshClient sshClient = SshClient.setUpDefaultClient();
    sshClient.start();

    try {
        // 通过 SSH 客户端进行认证
        sshClient.connect(user, host, 22)
                .verify()
                .getSession()
                .addPasswordIdentity(password)
                .auth();

        // 获取 SFTP 客户端
        try (SftpClient sftpClient = sshClient.createSftpClient()) {

            // 获取文件的输入流
            InputStream inputStream = sftpClient.open(remoteFilePath);

            // 将输入流转换为 byte 数组
            return convertInputStreamToByteArray(inputStream);

        } catch (IOException e) {
            System.err.println("Failed to download file via SFTP: " + e.getMessage());
        }
    } catch (IOException e) {
        System.err.println("SSH connection failed: " + e.getMessage());
    } finally {
        sshClient.stop();
    }
    return null;
}

public static byte[] convertInputStreamToByteArray(InputStream inputStream) {
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    byte[] buffer = new byte[4096]; // 4KB 缓冲区
    int bytesRead;

    try {
        while ((bytesRead = inputStream.read(buffer)) != -1) {
            byteArrayOutputStream.write(buffer, 0, bytesRead);
        }
        byteArrayOutputStream.flush();
    } catch (IOException e) {
        System.err.println("Failed to read from input stream: " + e.getMessage());
    }

    return byteArrayOutputStream.toByteArray();
}

} `

import com.jcraft.jsch.*;

import java.io.BufferedReader; import java.io.InputStreamReader;

public class SSHLogFetcherWithOffsetLimit {

public static void main(String[] args) {
    String host = "remote-server-ip";  // 远程服务器 IP 地址
    String user = "username";          // SSH 用户名
    String password = "password";      // SSH 密码
    String logFilePath = "/path/to/logfile.log"; // 日志文件路径
    int offset = 1000;  // 偏移量（跳过的行数）
    int limit = 200;    // 最大返回行数（最多返回多少行日志）

    Session session = null;
    ChannelExec channel = null;

    try {
        // 创建 JSch 对象
        JSch jsch = new JSch();

        // 创建 session
        session = jsch.getSession(user, host, 22);
        session.setPassword(password);

        // 禁用主机密钥检查
        session.setConfig("StrictHostKeyChecking", "no");

        // 连接到远程主机
        session.connect();

        // 创建执行命令的通道
        channel = (ChannelExec) session.openChannel("exec");

        // 构建命令：跳过前 offset 行，并获取后 limit 行
        String command = "sed -n '" + (offset + 1) + "," + (offset + limit) + "p' " + logFilePath;
        channel.setCommand(command);

        // 获取命令的输出
        BufferedReader reader = new BufferedReader(new InputStreamReader(channel.getInputStream()));

        // 连接通道
        channel.connect();

        // 输出日志内容
        String line;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        // 关闭通道和会话
        if (channel != null) {
            channel.disconnect();
        }
        if (session != null) {
            session.disconnect();
        }
    }
}

}

==session pool https://github.com/dstreev/hadoop-cli/commit/f418a41ea0520b37b7a2ad3cf85a763285730dcb#diff-9c5fb3d1b7e3b0f54bc5c4182965c4fe1f9023d449017cece3005d3f90e8e4d8