Package com.maybeitssquid.safeascii

Class ASCIIFilter

java.lang.Object
com.maybeitssquid.safeascii.ASCIIFilter
All Implemented Interfaces:
IntFunction<CharSequence>
public class ASCIIFilter extends Object implements IntFunction<CharSequence>
A filter function that selectively preserves ASCII characters.

This class processes Unicode codepoints, retaining them only if they are within the ASCII range (codepoints less than 128) and do not belong to any of the blocked Unicode categories defined at construction (see Character.getType(int)). Codepoints that do not meet these criteria are transformed into an empty string.

  • Constructor Details

    • ASCIIFilter

      public ASCIIFilter(byte... block)
      Create an ASCII filter that blocks characters of the specified Unicode categories.

      To create an instance that allows all ASCII characters, use: 

        ASCIIFilter ascii = new ASCIIFilter();

      To create an instance that disallows ASCII control characters, use: 

        ASCIIFilter blockControls = new ASCIIFilter(Character.CONTROL);
      Parameters:
      block - Unicode categories to block
      See Also:

  • Method Details

    • apply

      public CharSequence apply(int value)
      Processes a Unicode codepoint.
      Specified by:
      apply in interface IntFunction<CharSequence>
      Parameters:
      value - the codepoint to process.
      Returns:
      a string containing the character if it is a permitted ASCII character; otherwise, an empty string.