Package dev.frostlake.functions.scalar.file

Class FlGetFileType

java.lang.Object
dev.frostlake.functions.BuiltInFunction
dev.frostlake.functions.scalar.file.FlGetFileType
public class FlGetFileType extends BuiltInFunction
FL_GET_FILE_TYPE(file) — the file's single category name: image, video, audio, document, compressed or unknown.

Live-verified: the category is decided by the descriptor's CONTENT_TYPE ALONE, by exact case-sensitive match against a closed set (see FileContentTypes) — not the path, not the bytes. The sets overlap, so a predicate is not the same question: video/x-msvideo (an .avi) makes FL_IS_AUDIO TRUE while this function answers video.

This function does NOT propagate NULL: live, FL_GET_FILE_TYPE(NULL) is the string 'unknown', never NULL. The one-liner below is already exactly that — FileFunctionHelper.contentTypeOf(java.lang.Object) answers null for a NULL argument and FileContentTypes.fileType(java.lang.String) maps a null content type to unknown.

  • Constructor Details

    • FlGetFileType

      public FlGetFileType()

  • Method Details

    • evaluate

      public Object evaluate(List<Object> args)
      Description copied from class: BuiltInFunction
      Computes the function's result over its already-evaluated argument values. A SQL NULL argument arrives as Java null, and returning null makes the SQL result NULL.
      Specified by:
      evaluate in class BuiltInFunction
      Parameters:
      args - the argument values, in call order
      Returns:
      the function's value for these arguments, or null for SQL NULL

    • getMinArgCount

      public int getMinArgCount()
      Description copied from class: BuiltInFunction
      The fewest arguments a call to this function may pass; fewer is an argument-count error.
      Specified by:
      getMinArgCount in class BuiltInFunction
      Returns:
      the minimum accepted argument count

    • getMaxArgCount

      public int getMaxArgCount()
      Description copied from class: BuiltInFunction
      The most arguments a call to this function may pass; Integer.MAX_VALUE marks a variadic function (see BuiltInFunction.isVariadic()).
      Specified by:
      getMaxArgCount in class BuiltInFunction
      Returns:
      the maximum accepted argument count