Interface Escaper
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- 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<Bar>"
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, useCharEscaperBuilder
, or extendCharEscaper
orUnicodeEscaper
.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description java.lang.Appendable
escape(java.lang.Appendable out)
Returns anAppendable
instance which automatically escapes all text appended to it before passing the resulting text to an underlyingAppendable
.java.lang.String
escape(java.lang.String string)
Returns the escaped form of a given literal string.
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Method Detail
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escape
java.lang.String escape(java.lang.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 throwIllegalArgumentException
.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:
java.lang.NullPointerException
- ifstring
is nulljava.lang.IllegalArgumentException
- ifstring
contains badly formed UTF-16 or cannot be escaped for any other reason
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escape
java.lang.Appendable escape(java.lang.Appendable out)
Returns anAppendable
instance which automatically escapes all text appended to it before passing the resulting text to an underlyingAppendable
.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 throwIllegalArgumentException
.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 underlyingAppendable
to append escaped output to- Returns:
- an
Appendable
which passes text toout
after escaping it.
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