如何用Java处理Apache Mina SSHD SFTP服务器中的传入文件

Question

我想知道，如果有任何已经实现的侦听器处理传入文件在Apache Mina Sshd服务器，或者如果没有，我如何实现我自己的侦听器传入文件。

SFTP服务器代码

public class SftpServerStarter {

    private SshServer sshd;
    private final static Logger logger = LoggerFactory.getLogger(SftpServerStarter.class);

    public void start(){


        sshd = SshServer.setUpDefaultServer();
        sshd.setPort(22);
        sshd.setHost("localhost");

        sshd.setPasswordAuthenticator(new MyPasswordAuthenticator());
        sshd.setPublickeyAuthenticator(new MyPublickeyAuthenticator());
        sshd.setKeyPairProvider(new SimpleGeneratorHostKeyProvider());
        sshd.setSubsystemFactories(Arrays.<NamedFactory<Command>>asList(new SftpSubsystem.Factory()));
        sshd.setCommandFactory(new ScpCommandFactory());
        sshd.setFileSystemFactory(new VirtualFileSystemFactory("C:/root"));


        try {
            logger.info("Starting ...");
            sshd.start();
            logger.info("Started");
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            logger.info("Can not Start Server");
        }
    }

}

Answer 1

我开始使用@Gihan的建议，但在用户完成在某些客户端上传文件之前，文件监视器处理文件时遇到了一些问题。

以下是我从Mina的源代码中找到的解决方案。尽管Apache Mina的站点上的文档很稀疏，无用，但我认为这正是开发人员使用库的方式。

注意：由于您的需求可能与我的不同，请记住，这可能不是一个复制粘贴解决方案。您可能需要修改此代码以满足您的需求，但我相当相信，此代码确实提供了您所寻找的解决方案的关键。

创建实现org.apache.sshd.server.subsystem.sftp.sftpEventListener的自己的类。下面是我的一个例子。我的实现设置为在新上载或覆盖文件时运行一系列注册的FileUploadCompleteListener方法，并阻止用户导航或创建目录的尝试。

public class SFTPServiceSFTPEventListener implements SftpEventListener {

    Logger logger = Logger.getLogger(SFTPServiceSFTPEventListener.class);

    SFTPService service;

    public SFTPServiceSFTPEventListener(SFTPService service) {
        this.service = service;
    }

    public interface FileUploadCompleteListener {
        void onFileReady(File file);
    }

    private List<FileUploadCompleteListener> fileReadyListeners = new ArrayList<FileUploadCompleteListener>();

    public void addFileUploadCompleteListener(FileUploadCompleteListener listener) {
        fileReadyListeners.add(listener);
    }

    public void removeFileUploadCompleteListener(FileUploadCompleteListener listener) {
        fileReadyListeners.remove(listener);
    }

    @Override
    public void initialized(ServerSession serverSession, int version) {

    }

    @Override
    public void destroying(ServerSession serverSession) {

    }

    @Override
    public void open(ServerSession serverSession, String remoteHandle, Handle localHandle) {
        File openedFile = localHandle.getFile().toFile();
        if (openedFile.exists() && openedFile.isFile()) {
        }
    }

    @Override
    public void read(ServerSession serverSession, String remoteHandle, DirectoryHandle localHandle, Map<String,Path> entries) {

    }

    @Override
    public void read(ServerSession serverSession, String remoteHandle, FileHandle localHandle, long offset, byte[] data, int dataOffset, int dataLen, int readLen) {

    }

    @Override
    public void write(ServerSession serverSession, String remoteHandle, FileHandle localHandle, long offset, byte[] data, int dataOffset, int dataLen) {
    }

    @Override
    public void blocking(ServerSession serverSession,  String remoteHandle, FileHandle localHandle, long offset, long length, int mask) {
    }

    @Override
    public void blocked(ServerSession serverSession, String remoteHandle, FileHandle localHandle, long offset, long length, int mask, Throwable thrown) {
    }

    @Override
    public void unblocking(ServerSession serverSession, String remoteHandle, FileHandle localHandle, long offset, long length) {
    }

    @Override
    public void unblocked(ServerSession serverSession, String remoteHandle, FileHandle localHandle, long offset, long length, Boolean result, Throwable thrown) {
    }

    @Override
    public void close(ServerSession serverSession, String remoteHandle, Handle localHandle) {
        File closedFile = localHandle.getFile().toFile();
        if (closedFile.exists() && closedFile.isFile()) {
            logger.info(String.format("User %s closed file: \"%s\"", serverSession.getUsername(), localHandle.getFile().toAbsolutePath()));
            this.service.UserWroteFile(serverSession.getUsername(), localHandle.getFile());

            for (FileUploadCompleteListener fileReadyListener : fileReadyListeners) {
                fileReadyListener.onFileReady(closedFile);
            }
        }
    }

    @Override
    public void creating(ServerSession serverSession, Path path, Map<String,?> attrs) throws UnsupportedOperationException {
        logger.warn(String.format("Blocked user %s attempt to create a directory \"%s\"", serverSession.getUsername(), path.toString()));
        throw new UnsupportedOperationException("Creating sub-directories is not permitted.");
    }

    @Override
    public void created(ServerSession serverSession, Path path, Map<String,?> attrs, Throwable thrown) {
        String username = serverSession.getUsername();
        logger.info(String.format("User %s created: \"%s\"", username, path.toString()));
        service.UserWroteFile(username, path);
    }

    @Override
    public void moving(ServerSession serverSession, Path path, Path path1, Collection<CopyOption> collection) {

    }

    @Override
    public void moved(ServerSession serverSession, Path source, Path destination, Collection<CopyOption> collection, Throwable throwable) {
        String username = serverSession.getUsername();
        logger.info(String.format("User %s moved: \"%s\" to \"%s\"", username, source.toString(), destination.toString()));
        service.UserWroteFile(username, destination);
    }

    @Override
    public void removing(ServerSession serverSession, Path path) {

    }

    @Override
    public void removed(ServerSession serverSession, Path path, Throwable thrown) {

    }

    @Override
    public void linking(ServerSession serverSession, Path source, Path target, boolean symLink) throws UnsupportedOperationException {
        logger.warn(String.format("Blocked user %s attempt to create a link to \"%s\" at \"%s\"", serverSession.getUsername(), target.toString(), source.toString()));
        throw new UnsupportedOperationException("Creating links is not permitted");
    }

    @Override
    public void linked(ServerSession serverSession, Path source, Path target, boolean symLink, Throwable thrown) {

    }

    @Override
    public void modifyingAttributes(ServerSession serverSession, Path path, Map<String,?> attrs) {

    }

    @Override
    public void modifiedAttributes(ServerSession serverSession, Path path, Map<String,?> attrs, Throwable thrown) {
        String username = serverSession.getUsername();
        service.UserWroteFile(username, path);
    }
}

步骤2：将侦听器的实例添加到服务器

实现了类之后，只需在服务器上调用start()之前，实例化它并使用sftpsubsystemFactory将其添加到服务器：

// Your SSHD Server
SshServer sshd = SshServer.setUpDefaultServer();

SftpSubsystemFactory sftpSubsystemFactory= new SftpSubsystemFactory();

// This is where to put your implementation of SftpEventListener
SFTPServiceSFTPEventListener sftpEventListener = new SFTPServiceSFTPEventListener(this);
sftpEventListener.addFileUploadCompleteListener(new SFTPServiceSFTPEventListener.FileUploadCompleteListener() {
    @Override
    public void onFileReady(File file) {
        try {
            doThingsWithFile(file);
        } catch (Exception e) {
            logger.warn(String.format("An error occurred while attempting to do things with the file: \"%s\"", file.getName()), e);
        }
    }
});
sftpSubsystemFactory.addSftpEventListener(sftpEventListener);

List<NamedFactory<Command>> namedFactoryList = new ArrayList<NamedFactory<Command>>();
namedFactoryList.add(sftpSubsystemFactory);
sshd.setSubsystemFactories(namedFactoryList);

// Do your other init stuff...

sshd.start();