@Beta @GwtCompatible public abstract class ArrayBasedCharEscaper extends CharEscaper
CharEscaper that uses an array to quickly look up replacement
characters for a given char value. An additional safe range is
provided that determines whether char values without specific
replacements are to be considered safe and left unescaped or should be
escaped in a general way.
A good example of usage of this class is for Java source code escaping
where the replacement array contains information about special ASCII
characters such as \\t and \\n while escapeUnsafe(char)
is overridden to handle general escaping of the form \\uxxxx.
The size of the data structure used by ArrayBasedCharEscaper is
proportional to the highest valued character that requires escaping.
For example a replacement map containing the single character
'\u1000' will require approximately 16K of memory. If you
need to create multiple escaper instances that have the same character
replacement mapping consider using ArrayBasedEscaperMap.
| Modifier | Constructor and Description |
|---|---|
protected |
ArrayBasedCharEscaper(ArrayBasedEscaperMap escaperMap,
char safeMin,
char safeMax)
Creates a new ArrayBasedCharEscaper instance with the given replacement map
and specified safe range.
|
protected |
ArrayBasedCharEscaper(Map<Character,String> replacementMap,
char safeMin,
char safeMax)
Creates a new ArrayBasedCharEscaper instance with the given replacement map
and specified safe range.
|
| Modifier and Type | Method and Description |
|---|---|
protected char[] |
escape(char c)
Escapes a single character using the replacement array and safe range
values.
|
String |
escape(String s)
Returns the escaped form of a given literal string.
|
protected abstract char[] |
escapeUnsafe(char c)
Escapes a
char value that has no direct explicit value in the
replacement array and lies outside the stated safe range. |
escapeSlowasFunctionprotected ArrayBasedCharEscaper(Map<Character,String> replacementMap, char safeMin, char safeMax)
safeMax < safeMin then no characters
are considered safe.
If a character has no mapped replacement then it is checked against the
safe range. If it lies outside that, then escapeUnsafe(char) is
called, otherwise no escaping is performed.
replacementMap - a map of characters to their escaped representationssafeMin - the lowest character value in the safe rangesafeMax - the highest character value in the safe rangeprotected ArrayBasedCharEscaper(ArrayBasedEscaperMap escaperMap, char safeMin, char safeMax)
safeMax < safeMin then no characters
are considered safe. This initializer is useful when explicit instances of
ArrayBasedEscaperMap are used to allow the sharing of large replacement
mappings.
If a character has no mapped replacement then it is checked against the
safe range. If it lies outside that, then escapeUnsafe(char) is
called, otherwise no escaping is performed.
escaperMap - the mapping of characters to be escapedsafeMin - the lowest character value in the safe rangesafeMax - the highest character value in the safe rangepublic final String escape(String s)
CharEscaperescape in class CharEscapers - the literal string to be escapedstringprotected final char[] escape(char c)
escapeUnsafe(char) is called.escape in class CharEscaperc - the character to escape if necessarynull if no escaping was neededprotected abstract char[] escapeUnsafe(char c)
char value that has no direct explicit value in the
replacement array and lies outside the stated safe range. Subclasses should
override this method to provide generalized escaping for characters.
Note that arrays returned by this method must not be modified once they have been returned. However it is acceptable to return the same array multiple times (even for different input characters).
c - the character to escapenull if no escaping was
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