Package com.google.gdata.util.common.base

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 CharEscapers. To create your own escapers, use CharEscaperBuilder, or extend CharEscaper or UnicodeEscaper.

    • Method Detail

      • 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.
        • 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.
        • 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.