@Beta @GwtCompatible public final class PercentEscaper extends UnicodeEscaper
UnicodeEscaperthat escapes some set of Java characters using a UTF-8 based percent encoding scheme. The set of safe characters (those which remain unescaped) can be specified on construction.
This class is primarily used for creating URI escapers in
UrlEscapers but can be used directly if required. While URI escapers impose
specific semantics on which characters are considered 'safe', this class has
a minimal set of restrictions.
When escaping a String, the following rules apply:
plusForSpacewas specified, the space character " " is converted into a plus sign
For performance reasons the only currently supported character encoding of this class is UTF-8.
Note: This escaper produces uppercase hexadecimal sequences. From
"URI producers and normalizers should use uppercase hexadecimal digits for all percent-encodings."
|Constructor and Description|
Constructs a percent escaper with the specified safe characters and optional handling of the space character.
|Modifier and Type||Method and Description|
Escapes the given Unicode code point in UTF-8.
Returns the escaped form of a given literal string.
Scans a sub-sequence of characters from a given
public PercentEscaper(String safeChars, boolean plusForSpace)
Not that it is allowed, but not necessarily desirable to specify
as a safe character. This has the effect of creating an escaper which has no
well defined inverse but it can be useful when escaping additional characters.
safeChars- a non null string specifying additional safe characters for this escaper (the ranges 0..9, a..z and A..Z are always safe and should not be specified here)
plusForSpace- true if ASCII space should be escaped to
IllegalArgumentException- if any of the parameters were invalid
protected int nextEscapeIndex(CharSequence csq, int index, int end)
CharSequence, returning the index of the next character that requires escaping.
Note: When implementing an escaper, it is a good idea to override
this method for efficiency. The base class implementation determines
successive Unicode code points and invokes
UnicodeEscaper.escape(int) for each of
them. If the semantics of your escaper are such that code points in the
supplementary range are either all escaped or all unescaped, this method
can be implemented more efficiently using
Note however that if your escaper does not escape characters in the supplementary range, you should either continue to validate the correctness of any surrogate characters encountered or provide a clear warning to users that your escaper does not validate its input.
PercentEscaper for an example.
If you are escaping input in arbitrary successive chunks, then it is not
generally safe to use this method. If an input string ends with an
unmatched high surrogate character, then this method will throw
IllegalArgumentException. You should ensure your input is valid UTF-16 before calling this
Note: When implementing an escaper it is a good idea to override
this method for efficiency by inlining the implementation of
UnicodeEscaper.nextEscapeIndex(CharSequence, int, int) directly. Doing this for
PercentEscaper more than doubled the
performance for unescaped strings (as measured by
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