Package net.sf.basedb.util

Class FileUtil

java.lang.Object
net.sf.basedb.util.FileUtil
public class FileUtil
extends Object
This class collects some useful methods for file and stream handling.
Version:
2.0
Author:
Nicklas
Last modified
$Date$

  • Field Details

  • Constructor Details

    • FileUtil

      public FileUtil()

  • Method Details

    • copy

      public static long copy​(InputStream in, OutputStream out) throws IOException
      Copy from the input stream to the output stream until end of file is reached.
      Parameters:
      in - The InputStream to read from
      out - The OutputStream to write to
      Returns:
      The number of bytes copied
      Throws:
      IOException - This exception is thrown if there is an error

    • copy

      public static long copy​(InputStream in, OutputStream out, AbsoluteProgressReporter progress) throws IOException
      Copy from the input stream to the output stream until end of file is reached.
      Parameters:
      in - The InputStream to read from
      out - The OutputStream to write to
      progress - An optional progress reporter
      Returns:
      The number of bytes copied
      Throws:
      IOException - This exception is thrown if there is an error
      Since:
      2.5

    • copy

      public static long copy​(Reader in, Writer out) throws IOException
      Copy from the reader to the writer until end of file is reached.
      Parameters:
      in - The Reader to read from
      out - The Writer to write to
      Returns:
      The number of characters copied
      Throws:
      IOException - This exception is thrown if there is an error
      Since:
      2.12

    • copy

      public static long copy​(Reader in, Writer out, AbsoluteProgressReporter progress) throws IOException
      Copy from the reader to the writer until end of file is reached.
      Parameters:
      in - The Reader to read from
      out - The Writer to write to
      progress - An optional progress reporter
      Returns:
      The number of characters copied
      Throws:
      IOException - This exception is thrown if there is an error
      Since:
      2.12

    • read

      public static long read​(InputStream in) throws IOException
      Read from the input stream until the end is reached.
      Parameters:
      in - The InputStream to read from
      Returns:
      The number of bytes copied
      Throws:
      IOException - This exception is thrown if there is an error
      Since:
      2.4

    • close

      public static void close​(InputStream in)
      Close an input stream without throwing an exception.
      Parameters:
      in - The input stream to close
      Since:
      2.9

    • close

      public static void close​(OutputStream out)
      Close an output stream without throwing an exception.
      Parameters:
      out - The output stream to close
      Since:
      2.9

    • close

      public static void close​(Closeable c)
      Close a Closeable without throwing an exception.
      Parameters:
      c - The object to close
      Since:
      3.5

    • close

      public static void close​(AutoCloseable c)
      Close a AutoCloseable without throwing an exception.
      Parameters:
      c - The object to close
      Since:
      3.18

    • getInputStream

      public static InputStream getInputStream​(File file) throws IOException
      Get a buffered InputStream object reading from the specified file.
      Parameters:
      file - The path to the file to read from
      Returns:
      A buffered InputStream
      Throws:
      IOException - If the stream cannot be opened

    • getOutputStream

      public static OutputStream getOutputStream​(File file) throws IOException
      Get a buffered OutputStream object writing to the specified file.
      Parameters:
      file - The path to the file to write to
      Returns:
      A buffered OutputStream
      Throws:
      IOException - If the stream cannot be opened

    • checkMagicNumber

      public static boolean checkMagicNumber​(PushbackInputStream pin, byte[] bCheck) throws IOException
      Take a peek at an input stream and check if the first few bytes matches the bCheck parameter. After the check the bytes are pushed back to the stream again. This method is useful to check the file format of a file, which can often be done by checing the first few bytes at the start of the file. For example to check if the file is gzip file:

      bCheck = new byte[] { 0x1f, (byte)0x8b };

      Parameters:
      pin - The input stream to read from which must have large enough buffer to be able to unread the bytes
      bCheck - The byte values to use for comparison
      Returns:
      TRUE if the file matches the specified bytes, FALSE otherwise
      Throws:
      IOException - If there is an error reading or unreading the bytes
      NullPointerException - If pin or bCheck is null
      IllegalArgumentException - If bCheck is zero length
      Since:
      2.4

    • getDirectoryTree

      public static Map<Directory,​List<Directory>> getDirectoryTree​(DbControl dc, Directory directory) throws InvalidDataException, BaseException
      Get the complete tree of sub-directories from a given directory.

      NOTE!!! This method has very bad performance on large directory trees. Consider if it is not possible to use the loadMinimalDirectoryTree(DbControl, Directory...) instead together with lazy loading of subdirectories.

      Parameters:
      dc - DbControl used to access the database.
      directory - The directory to start with
      Returns:
      A Map which maps a directory to a list of it's sub-directories. Directories without sub-directories are not included in the map.
      Throws:
      InvalidDataException - If the directory is null
      BaseException - If there is another error

    • loadMinimalDirectoryTree

      public static Map<Directory,​List<Directory>> loadMinimalDirectoryTree​(DbControl dc, Directory... directories) throws InvalidDataException, BaseException
      Load a minimal directory tree that includes at least all the specified directories and their parent directories all the way up to the root or as far as the logged in user has read permission.
      Parameters:
      dc - A DbControl for accessing the database
      directories - An array of directories
      Returns:
      A Map which maps a directory to a list of it's sub-directories. The map is guaranteed to contain an entry for each of the given directories, but the list may be empty if there are no subdirectories
      Throws:
      BaseException - If there is an error
      InvalidDataException
      Since:
      2.11

    • loadMinimalDirectoryTree

      public static Map<Directory,​List<Directory>> loadMinimalDirectoryTree​(DbControl dc, Collection<Include> include, Directory... directories) throws InvalidDataException, BaseException
      Load a minimal directory tree that includes at least all the specified directories and their parent directories all the way up to the root or as far as the logged in user has read permission.
      Parameters:
      dc - A DbControl for accessing the database
      include - Include settings for loading sub directories
      directories - An array of directories
      Returns:
      A Map which maps a directory to a list of it's sub-directories. The map is guaranteed to contain an entry for each of the given directories, but the list may be empty if there are no subdirectories
      Throws:
      BaseException - If there is an error
      InvalidDataException
      Since:
      3.11

    • findFiles

      public static List<File> findFiles​(File directory, FileFilter filter)
      Find files matching a given filter in a directory. If the filter returns sub-directories, this method will check those directories too. Use, for example, the RegexpFileFilter to look for files matching a regular expression.
      Parameters:
      directory - The parent directory to search in
      filter - A filter which specifies which files to find, or null to find all files
      Returns:
      A List with the files in directory that matches the filter, or null if the specified directory doesn't exists or isn't a directory
      Since:
      2.5
      See Also:
      RegexpFileFilter

    • deleteEmptyDirectories

      public static int deleteEmptyDirectories​(File root, boolean deleteRoot)
      Deletes all empty subdirectories and, optionally, also the root directory.
      Parameters:
      root - The root directory to start looking in
      deleteRoot - TRUE to also delete the root directory if it is empty, FALSE to leave it
      Returns:
      The number of deleted directories
      Since:
      2.13

    • doRecursively

      public static void doRecursively​(DbControl dc, Directory root, Filter<? super Directory> dirFilter, Filter<? super File> fileFilter)
      Do something recursively to all files and sub-directories in specified root directory. If no directory filter is specified, all subdirectories are processed, otherwise only those directories were the Filter.evaluate(Object) method returns TRUE.

      Files are only loaded if a file filter is specified. The return value of the evaluate method is ignored.

      The files and directories may be processed in any order.

      NOTE! The intention of this method is that the filter should have have a "side-effect" that does some work on the files/ sub-directories.

      Parameters:
      dc - A DbControl to use for database access
      root - The root directory
      dirFilter - A filter that selects/rejects sub-directories
      fileFilter - A filter that does something with the file
      Since:
      2.13

    • createTempDirectory

      public static File createTempDirectory​(String prefix, String suffix, File directory) throws IOException
      Creates a temporary directory. This method uses the built-in File.createTempFile(String, String, File) method to first crete a temporary file, that is then deleted and made into a directory instead. This should ensure that a new empty directory is created each time this method is called. The "temporary" nature of this method doesn't involve cleaning up or removing the created directory. It is the responsibility of the calling code to remove every file and subdirectory as well as the returned directory. This can for example be done with the deleteTempDirectory(File) method.
      Parameters:
      prefix - A prefix that is used in the directory name it must be at least 3 characters long.
      suffix - An optional suffix for the directory name
      directory - An optional parent directory in which the temporary directory should be created, or null to use the system temporary directory
      Returns:
      A reference to the created directory
      Throws:
      IOException - If there is a problem with the directory creation
      Since:
      2.15
      See Also:
      File.createTempFile(String, String, File)

    • deleteTempDirectory

      public static int deleteTempDirectory​(File root)
      Recursively delete all files and subdirectories within a given directory and the also the given directory itself.
      Parameters:
      root - The root directory to start looking in
      Returns:
      The number of deleted files and directories
      Since:
      2.15

    • uploadFiles

      public static List<File> uploadFiles​(DbControl dc, Directory toDir, File fromDir, FileFilter filter, boolean overwrite, ProgressReporter progress) throws IOException
      Upload multiple files to BASE.
      Parameters:
      toDir - The directory in the BASE file system that the files should be uploaded to
      fromDir - The directory in the local file system to scan for files to upload if the directory doesn't exists or is empty an empty list is returned
      filter - An optional filter that decides which files that should be uploaded or not, if null all files, including subdirectories, are uploaded
      overwrite - TRUE if existing files should be overwritten, FALSE to only overwrite files that have been marked for removal
      progress - An optional progress reporter
      Returns:
      A list with the new file items that were created
      Throws:
      IOException
      Since:
      2.16