Class SFTPv3Client

java.lang.Object
com.trilead.ssh2.SFTPv3Client

public class SFTPv3Client extends Object
A SFTPv3Client represents a SFTP (protocol version 3) client connection tunnelled over a SSH-2 connection. This is a very simple (synchronous) implementation.

Basically, most methods in this class map directly to one of the packet types described in draft-ietf-secsh-filexfer-02.txt.

Note: this is experimental code.

Error handling: the methods of this class throw IOExceptions. However, unless there is catastrophic failure, exceptions of the type SFTPv3Client will be thrown (a subclass of IOException). Therefore, you can implement more verbose behavior by checking if a thrown exception if of this type. If yes, then you can cast the exception and access detailed information about the failure.

Notes about file names, directory names and paths, copy-pasted from the specs:

  • SFTP v3 represents file names as strings. File names are assumed to use the slash ('/') character as a directory separator.
  • File names starting with a slash are "absolute", and are relative to the root of the file system. Names starting with any other character are relative to the user's default directory (home directory).
  • Servers SHOULD interpret a path name component ".." as referring to the parent directory, and "." as referring to the current directory. If the server implementation limits access to certain parts of the file system, it must be extra careful in parsing file names when enforcing such restrictions. There have been numerous reported security bugs where a ".." in a path name has allowed access outside the intended area.
  • An empty path name is valid, and it refers to the user's default directory (usually the user's home directory).

If you are still not tired then please go on and read the comment for setCharset(String).

  • Constructor Details

    • SFTPv3Client

      public SFTPv3Client(Connection conn, PrintStream debug) throws IOException
      Deprecated.
      this constructor (debug version) will disappear in the future, use SFTPv3Client(Connection) instead.
      Create a SFTP v3 client.
      Parameters:
      conn - The underlying SSH-2 connection to be used.
      debug -
      Throws:
      IOException
    • SFTPv3Client

      public SFTPv3Client(Connection conn) throws IOException
      Create a SFTP v3 client.
      Parameters:
      conn - The underlying SSH-2 connection to be used.
      Throws:
      IOException
  • Method Details

    • setCharset

      public void setCharset(String charset) throws IOException
      Set the charset used to convert between Java Unicode Strings and byte encodings used by the server for paths and file names. Unfortunately, the SFTP v3 draft says NOTHING about such conversions (well, with the exception of error messages which have to be in UTF-8). Newer drafts specify to use UTF-8 for file names (if I remember correctly). However, a quick test using OpenSSH serving a EXT-3 filesystem has shown that UTF-8 seems to be a bad choice for SFTP v3 (tested with filenames containing german umlauts). "windows-1252" seems to work better for Europe. Luckily, "windows-1252" is the platform default in my case =).

      If you don't set anything, then the platform default will be used (this is the default behavior).

      Parameters:
      charset - the name of the charset to be used or null to use the platform's default encoding.
      Throws:
      IOException
      See Also:
    • getCharset

      public String getCharset()
      The currently used charset for filename encoding/decoding.
      Returns:
      The name of the charset (null if the platform's default charset is being used)
      See Also:
    • fstat

      public SFTPv3FileAttributes fstat(SFTPv3FileHandle handle) throws IOException
      Retrieve the file attributes of an open file.
      Parameters:
      handle - a SFTPv3FileHandle handle.
      Returns:
      a SFTPv3FileAttributes object.
      Throws:
      IOException
    • stat

      public SFTPv3FileAttributes stat(String path) throws IOException
      Retrieve the file attributes of a file. This method follows symbolic links on the server.
      Parameters:
      path - See the comment for the class for more details.
      Returns:
      a SFTPv3FileAttributes object.
      Throws:
      IOException
      See Also:
    • lstat

      public SFTPv3FileAttributes lstat(String path) throws IOException
      Retrieve the file attributes of a file. This method does NOT follow symbolic links on the server.
      Parameters:
      path - See the comment for the class for more details.
      Returns:
      a SFTPv3FileAttributes object.
      Throws:
      IOException
      See Also:
    • readLink

      public String readLink(String path) throws IOException
      Read the target of a symbolic link.
      Parameters:
      path - See the comment for the class for more details.
      Returns:
      The target of the link.
      Throws:
      IOException
    • setstat

      public void setstat(String path, SFTPv3FileAttributes attr) throws IOException
      Modify the attributes of a file. Used for operations such as changing the ownership, permissions or access times, as well as for truncating a file.
      Parameters:
      path - See the comment for the class for more details.
      attr - A SFTPv3FileAttributes object. Specifies the modifications to be made to the attributes of the file. Empty fields will be ignored.
      Throws:
      IOException
    • fsetstat

      public void fsetstat(SFTPv3FileHandle handle, SFTPv3FileAttributes attr) throws IOException
      Modify the attributes of a file. Used for operations such as changing the ownership, permissions or access times, as well as for truncating a file.
      Parameters:
      handle - a SFTPv3FileHandle handle
      attr - A SFTPv3FileAttributes object. Specifies the modifications to be made to the attributes of the file. Empty fields will be ignored.
      Throws:
      IOException
    • createSymlink

      public void createSymlink(String src, String target) throws IOException
      Create a symbolic link on the server. Creates a link "src" that points to "target".
      Parameters:
      src - See the comment for the class for more details.
      target - See the comment for the class for more details.
      Throws:
      IOException
    • canonicalPath

      public String canonicalPath(String path) throws IOException
      Have the server canonicalize any given path name to an absolute path. This is useful for converting path names containing ".." components or relative pathnames without a leading slash into absolute paths.
      Parameters:
      path - See the comment for the class for more details.
      Returns:
      An absolute path.
      Throws:
      IOException
    • getProtocolVersion

      public int getProtocolVersion()
      Returns the negotiated SFTP protocol version between the client and the server.
      Returns:
      SFTP protocol version, i.e., "3".
    • close

      public void close()
      Close this SFTP session. NEVER forget to call this method to free up resources - even if you got an exception from one of the other methods. Sometimes these other methods may throw an exception, saying that the underlying channel is closed (this can happen, e.g., if the other server sent a close message.) However, as long as you have not called the close() method, you are likely wasting resources.
    • ls

      public Vector ls(String dirName) throws IOException
      List the contents of a directory.
      Parameters:
      dirName - See the comment for the class for more details.
      Returns:
      A Vector containing SFTPv3DirectoryEntry objects.
      Throws:
      IOException
    • mkdir

      public void mkdir(String dirName, int posixPermissions) throws IOException
      Create a new directory.
      Parameters:
      dirName - See the comment for the class for more details.
      posixPermissions - the permissions for this directory, e.g., "0700" (remember that this is octal noation). The server will likely apply a umask.
      Throws:
      IOException
    • rm

      public void rm(String fileName) throws IOException
      Remove a file.
      Parameters:
      fileName - See the comment for the class for more details.
      Throws:
      IOException
    • rmdir

      public void rmdir(String dirName) throws IOException
      Remove an empty directory.
      Parameters:
      dirName - See the comment for the class for more details.
      Throws:
      IOException
    • mv

      public void mv(String oldPath, String newPath) throws IOException
      Move a file or directory.
      Parameters:
      oldPath - See the comment for the class for more details.
      newPath - See the comment for the class for more details.
      Throws:
      IOException
    • openFileRO

      public SFTPv3FileHandle openFileRO(String fileName) throws IOException
      Open a file for reading.
      Parameters:
      fileName - See the comment for the class for more details.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • openFileRW

      public SFTPv3FileHandle openFileRW(String fileName) throws IOException
      Open a file for reading and writing.
      Parameters:
      fileName - See the comment for the class for more details.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • createFile

      public SFTPv3FileHandle createFile(String fileName) throws IOException
      Create a file and open it for reading and writing. Same as createFile(fileName, null).
      Parameters:
      fileName - See the comment for the class for more details.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • createFile

      public SFTPv3FileHandle createFile(String fileName, SFTPv3FileAttributes attr) throws IOException
      Create a file and open it for reading and writing. You can specify the default attributes of the file (the server may or may not respect your wishes).
      Parameters:
      fileName - See the comment for the class for more details.
      attr - may be null to use server defaults. Probably only the uid, gid and permissions (remember the server may apply a umask) entries of the SFTPv3FileHandle structure make sense. You need only to set those fields where you want to override the server's defaults.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • createFileTruncate

      public SFTPv3FileHandle createFileTruncate(String fileName) throws IOException
      Create a file (truncate it if it already exists) and open it for reading and writing. Same as createFileTruncate(fileName, null).
      Parameters:
      fileName - See the comment for the class for more details.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • createFileTruncate

      public SFTPv3FileHandle createFileTruncate(String fileName, SFTPv3FileAttributes attr) throws IOException
      reate a file (truncate it if it already exists) and open it for reading and writing. You can specify the default attributes of the file (the server may or may not respect your wishes).
      Parameters:
      fileName - See the comment for the class for more details.
      attr - may be null to use server defaults. Probably only the uid, gid and permissions (remember the server may apply a umask) entries of the SFTPv3FileHandle structure make sense. You need only to set those fields where you want to override the server's defaults.
      Returns:
      a SFTPv3FileHandle handle
      Throws:
      IOException
    • read

      public int read(SFTPv3FileHandle handle, long fileOffset, byte[] dst, int dstoff, int len) throws IOException
      Read bytes from a file. No more than 32768 bytes may be read at once. Be aware that the semantics of read() are different than for Java streams.

      • The server will read as many bytes as it can from the file (up to len), and return them.
      • If EOF is encountered before reading any data, -1 is returned.
      • If an error occurs, an exception is thrown
      • .
      • For normal disk files, it is guaranteed that the server will return the specified number of bytes, or up to end of file. For, e.g., device files this may return fewer bytes than requested.
      Parameters:
      handle - a SFTPv3FileHandle handle
      fileOffset - offset (in bytes) in the file
      dst - the destination byte array
      dstoff - offset in the destination byte array
      len - how many bytes to read, 0 < len <= 32768 bytes
      Returns:
      the number of bytes that could be read, may be less than requested if the end of the file is reached, -1 is returned in case of EOF
      Throws:
      IOException
    • write

      public void write(SFTPv3FileHandle handle, long fileOffset, byte[] src, int srcoff, int len) throws IOException
      Write bytes to a file. If len > 32768, then the write operation will be split into multiple writes.
      Parameters:
      handle - a SFTPv3FileHandle handle.
      fileOffset - offset (in bytes) in the file.
      src - the source byte array.
      srcoff - offset in the source byte array.
      len - how many bytes to write.
      Throws:
      IOException
    • closeFile

      public void closeFile(SFTPv3FileHandle handle) throws IOException
      Close a file.
      Parameters:
      handle - a SFTPv3FileHandle handle
      Throws:
      IOException