Class FileContentReader

All Implemented Interfaces:
ContentAccessor, ContentReader, FileContentReader

@AlfrescoPublicApi public class FileContentReader extends AbstractContentReader implements FileContentReader
Provides direct access to a local file.

This class does not provide remote access to the file.

Author:
Derek Hulley
  • Field Details

  • Constructor Details

    • FileContentReader

      public FileContentReader(File file)
      Constructor that builds a URL based on the absolute path of the file.
      Parameters:
      file - the file for reading. This will most likely be directly related to the content URL.
    • FileContentReader

      public FileContentReader(File file, String url)
      Constructor that explicitely sets the URL that the reader represents.
      Parameters:
      file - the file for reading. This will most likely be directly related to the content URL.
      url - the relative url that the reader represents
  • Method Details

    • getSafeContentReader

      public static ContentReader getSafeContentReader(ContentReader existingReader, String msgTemplate, Object... args)
      Checks the existing reader provided and replaces it with a reader onto some fake content if required. If the existing reader is invalid, an debug message will be logged under this classname category.

      It is a convenience method that clients can use to cheaply get a reader that is valid, regardless of whether the initial reader is valid.

      Parameters:
      existingReader - a potentially invalid reader or null
      msgTemplate - the template message that will used to format the final fake content
      args - arguments to put into the fake content
      Returns:
      Returns a the existing reader or a new reader onto some generated text content
    • getFile

      public File getFile()
      Specified by:
      getFile in interface FileContentReader
      Returns:
      Returns the file that this reader accesses
    • exists

      public boolean exists()
      Specified by:
      exists in interface ContentReader
      Specified by:
      exists in interface FileContentReader
      Returns:
      Whether the file exists or not
    • getSize

      public long getSize()
      Specified by:
      getSize in interface ContentAccessor
      See Also:
    • getLastModified

      public long getLastModified()
      Specified by:
      getLastModified in interface ContentReader
      See Also:
    • createReader

      protected ContentReader createReader() throws ContentIOException
      The URL of the write is known from the start and this method contract states that no consideration needs to be taken w.r.t. the stream state.
      Specified by:
      createReader in class AbstractContentReader
      Returns:
      Returns a reader onto the location referenced by this instance. The instance must always be a new instance.
      Throws:
      ContentIOException
    • getDirectReadableChannel

      protected ReadableByteChannel getDirectReadableChannel() throws ContentIOException
      Description copied from class: AbstractContentReader
      Provides low-level access to read content from the repository.

      This is the only of the content reading methods that needs to be implemented by derived classes. All other content access methods make use of this in their underlying implementations.

      Specified by:
      getDirectReadableChannel in class AbstractContentReader
      Returns:
      Returns a channel from which content can be read
      Throws:
      ContentIOException - if the channel could not be opened or the underlying content has disappeared
    • canWrite

      @Deprecated public boolean canWrite()
      Deprecated.
      Since 5.1. This method has no value: a file reader can never write (DH: 2015/02/17)
      Returns:
      Returns false as this is a reader