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 scanner.

For example, an XML escaper would convert the literal string "Foo<Bar>" into "Foo<Bar>" to prevent "<Bar>" from being confused with an XML tag. When the resulting XML document is parsed, the scanner 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

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CharEscapers

. To create your own escapers, use

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CharEscaperBuilder

, or extend

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CharEscaper

or UnicodeEscaper.

Method Summary

Modifier and Type	Method	Description
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.
String	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.