@Beta @GwtCompatible public final class PercentEscaper extends UnicodeEscaper
UnicodeEscaper that 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:
plusForSpace was 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.
| Constructor and Description |
|---|
PercentEscaper(String safeChars,
boolean plusForSpace)
Constructs a percent escaper with the specified safe characters and optional handling of the
space character.
|
| Modifier and Type | Method and Description |
|---|---|
protected char[] |
escape(int cp)
Escapes the given Unicode code point in UTF-8.
|
String |
escape(String s)
Returns the escaped form of a given literal string.
|
protected int |
nextEscapeIndex(CharSequence csq,
int index,
int end)
Scans a sub-sequence of characters from a given
CharSequence, returning the index of
the next character that requires escaping. |
codePointAt, escapeSlowasFunctionpublic 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 + rather than %20IllegalArgumentException - if any of the parameters were invalidprotected int nextEscapeIndex(CharSequence csq, int index, int end)
UnicodeEscaperCharSequence, 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 CharSequence.charAt(int).
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.
See PercentEscaper for an example.
nextEscapeIndex in class UnicodeEscapercsq - a sequence of charactersindex - the index of the first character to be scannedend - the index immediately after the last character to be scannedpublic String escape(String s)
UnicodeEscaperIf 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 method.
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 CharEscapersBenchmark).
escape in class UnicodeEscapers - the literal string to be escapedstringprotected char[] escape(int cp)
escape in class UnicodeEscapercp - the Unicode code point to escape if necessarynull if no escaping was neededCopyright © 2010–2017. All rights reserved.