Package org.springframework.integration.file

Interface DirectoryScanner

All Known Implementing Classes:
DefaultDirectoryScanner, HeadDirectoryScanner, RecursiveDirectoryScanner
public interface DirectoryScanner
Strategy for scanning directories. Implementations may select all children and grandchildren of the scanned directory in any order. This interface is intended to enable the customization of selection, locking and ordering of files in a directory like RecursiveDirectoryScanner. If the only requirement is to ignore certain files a EntryListFilter implementation should suffice.
Author:
Iwein Fuld

  • Method Summary

    Modifier and Type Method Description
    List<File> listFiles​(File directory)
    Scans the directory according to the strategy particular to this implementation and returns the selected files as a File array.
    void setFilter​(FileListFilter<File> filter)
    Sets a custom filter to be used by this scanner.
    void setLocker​(FileLocker locker)
    Sets a custom locker to be used by this scanner.
    boolean tryClaim​(File file)
    Claim the file to process.

  • Method Details

    • listFiles

      List<File> listFiles​(File directory) throws IllegalArgumentException
      Scans the directory according to the strategy particular to this implementation and returns the selected files as a File array. This method may never return files that are rejected by the filter.
      Parameters:
      directory - the directory to scan for files
      Returns:
      a list of files representing the content of the directory
      Throws:
      IllegalArgumentException - if the input is incorrect

    • setFilter

      void setFilter​(FileListFilter<File> filter)
      Sets a custom filter to be used by this scanner. The filter will get a chance to reject files before the scanner presents them through its listFiles method. A scanner may use additional filtering that is out of the control of the provided filter.
      Parameters:
      filter - the custom filter to be used

    • setLocker

      void setLocker​(FileLocker locker)
      Sets a custom locker to be used by this scanner. The locker will get a chance to lock files and reject claims on files that are already locked.
      Parameters:
      locker - the custom locker to be used

    • tryClaim

      boolean tryClaim​(File file)
      Claim the file to process. It is up to the implementation to decide what additional safe guards are required to attain a claim to the file. But if a locker is set implementations MUST invoke its lock method and MUST return false if the locker did not grant the lock.
      Parameters:
      file - file to be claimed
      Returns:
      true if the claim was granted false otherwise