Interface Escaper

All Known Implementing Classes:
PercentEscaper, UnicodeEscaper

public interface Escaper
An object that converts literal text into a format safe for inclusion in a particular context (such as an XML document). Typically (but not always), the inverse process of "unescaping" the text is performed automatically by the relevant parser.

For example, an XML escaper would convert the literal string "Foo<Bar>" into "Foo&lt;Bar&gt;" to prevent "<Bar>" from being confused with an XML tag. When the resulting XML document is parsed, the parser API will return this text as the original literal string "Foo<Bar>".

An Escaper instance is required to be stateless, and safe when used concurrently by multiple threads.

Several popular escapers are defined as constants in the class

invalid reference
CharEscapers
. To create your own escapers, use
invalid reference
CharEscaperBuilder
, or extend
invalid reference
CharEscaper
or UnicodeEscaper.
  • Method Summary

    Modifier and Type
    Method
    Description
    Returns an Appendable instance which automatically escapes all text appended to it before passing the resulting text to an underlying Appendable.
    escape(String string)
    Returns the escaped form of a given literal string.
  • Method Details

    • escape

      String escape(String string)
      Returns the escaped form of a given literal string.

      Note that this method may treat input characters differently depending on the specific escaper implementation.

      • UnicodeEscaper handles UTF-16 correctly, including surrogate character pairs. If the input is badly formed the escaper should throw IllegalArgumentException.
      • invalid reference
        CharEscaper
        handles Java characters independently and does not verify the input for well formed characters. A CharEscaper should not be used in situations where input is not guaranteed to be restricted to the Basic Multilingual Plane (BMP).
      Parameters:
      string - the literal string to be escaped
      Returns:
      the escaped form of string
      Throws:
      NullPointerException - if string is null
      IllegalArgumentException - if string contains badly formed UTF-16 or cannot be escaped for any other reason
    • escape

      Appendable escape(Appendable out)
      Returns an Appendable instance which automatically escapes all text appended to it before passing the resulting text to an underlying Appendable.

      Note that this method may treat input characters differently depending on the specific escaper implementation.

      • UnicodeEscaper handles UTF-16 correctly, including surrogate character pairs. If the input is badly formed the escaper should throw IllegalArgumentException.
      • invalid reference
        CharEscaper
        handles Java characters independently and does not verify the input for well formed characters. A CharEscaper should not be used in situations where input is not guaranteed to be restricted to the Basic Multilingual Plane (BMP).
      Parameters:
      out - the underlying Appendable to append escaped output to
      Returns:
      an Appendable which passes text to out after escaping it.