org.pfsw.text

Class StringPattern

java.lang.Object

org.pfsw.text.AStringFilter

org.pfsw.text.StringPattern

All Implemented Interfaces:

java.io.Serializable, IObjectFilter<java.lang.String>, IJSONConvertible, IStringFilter, IStringRepresentation

public class StringPattern
extends AStringFilter
implements java.io.Serializable, IJSONConvertible, IStringRepresentation

This class provides services for checking strings against string-patterns. Currently it supports the wildcards
'*' for any number of any character and
'?' for any single character.

The API is very simple:

There are two class methods match() and matchIgnoreCase().
Example:
StringPattern.match( 'Hello World", "H* W*" ) ; --> evaluates to true
StringPattern.matchIgnoreCase( 'StringPattern", "str???pat*" ) ; --> evaluates to true

To be compatible with most pattern engines this class also supports that the multi-char wildcard '*' matches empty string. By default it doesn't ! To switch on this behaviour call
pattern.multiCharWildcardMatchesEmptyString(true);
If this option is set to true, the following example returns true, otherwise it would return false:

 StringPattern pattern = new StringPattern( "Fred*" ) ;
 pattern.multiCharWildcardMatchesEmptyString(true);
 return pattern.matches( "Fred" ) ; // <== returns true
 

It is also possible to instantiate new pattern object by using the static create() methods rather than the constructors. These methods will create new patterns that have the multiCharWildcardMatchesEmptyString option initialized to true.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static char	DEFAULT_MULTICHAR_WILDCARD
protected static char	DEFAULT_SINGLECHAR_WILDCARD
protected static java.lang.String	SWITCH_OFF
protected static java.lang.String	SWITCH_ON

Fields inherited from interface org.pfsw.bif.text.IJSONConvertible

JSON_ARRAY_END, JSON_ARRAY_START, JSON_ELEMENT_SEPARATOR, JSON_LITERAL_FALSE, JSON_LITERAL_NULL, JSON_LITERAL_TRUE, JSON_OBJECT_END, JSON_OBJECT_START, JSON_PAIR_SEPARATOR, JSON_STRING_DELIMITER, JSON_STRING_ESCAPE

Fields inherited from interface org.pfsw.bif.text.IStringFilter

ALL, NONE

Constructor Summary

Constructors

Constructor and Description
StringPattern(java.lang.String pattern) Initializes the new instance with the string pattern.
StringPattern(java.lang.String pattern, boolean ignoreCase) Initializes the new instance with the string pattern and the selection, if case should be ignored when comparing characters.
StringPattern(java.lang.String pattern, boolean ignoreCase, char digitWildcard) Initializes the new instance with the string pattern and the selection, if case should be ignored when comparing characters plus a wildcard character for digits.
StringPattern(java.lang.String pattern, char digitWildcard) Initializes the new instance with the string pattern and a digit wildcard character.

Method Summary

Modifier and Type	Method and Description
void	appendAsJSONString(java.lang.Appendable output) The receiver of this method must append its internal state as JSON string representation to the given buffer.
java.lang.String	asString() Returns the string representation of the implementing object.
protected boolean	charsAreEqual(char probeChar, char patternChar)
static boolean	containsWildcard(java.lang.String aString) Returns true if the given string contains a single or multi character wildcard.
StringPattern	copy() Returns a copy of this pattern.
static StringPattern	create(java.lang.String pattern) Returns a new instance with the string pattern.
static StringPattern	create(java.lang.String pattern, boolean ignoreCase) Returns a new instance with the string pattern and the selection, if case should be ignored when comparing characters.
static StringPattern	create(java.lang.String pattern, boolean ignoreCase, char digitWildcard) Returns a new instance with the string pattern and the selection, if case should be ignored when comparing characters plus a wildcard character for digits.
static StringPattern	create(java.lang.String pattern, char digitWildcard) Returns anew instance with the string pattern and a digit wildcard character.
protected java.lang.Character	digitWildcard()
protected void	digitWildcard(java.lang.Character newValue)
protected char	digitWildcardChar()
protected boolean	endNotReached(char character)
protected boolean	endReached(char character)
boolean	equals(java.lang.Object obj) Returns true if the given object is equal to the receiver.
protected boolean	eventuallyMatched(char probeCh, char patternCh, StringExaminer patternIterator)
static char	getDefaultMultiCharWildcard() Returns the character that is used to specify any number of any character.
static char	getDefaultSingleCharWildcard() Returns the character that is used to specify any single character.
boolean	getIgnoreCase() Returns whether or not the pattern matching ignores upper and lower case
char	getMultiCharWildcard() Returns the wildcard character that is used as placeholder for zero to many occurances of any character(s).
java.lang.String	getPattern() Returns the pattern as string.
protected char	getPatternChar(StringExaminer patternIterator, char probeCh)
char	getSingleCharWildcard() Returns the wildcard character that is used as placeholder for a single occurance of any character.
protected boolean	hasDigitWildcard()
int	hashCode() Returns a hash code value for the object.
boolean	hasWildcard() Returns true if the pattern contains any '*' or '?' or digit wildcard wildcard character.
protected java.lang.String	ignoreCaseAsString()
protected java.lang.String	inspectString()
static boolean	match(java.lang.String probe, java.lang.String pattern) Returns true, if the given probe string matches the given pattern.
boolean	matches(java.lang.String probe) Tests if a specified string matches the pattern.
static boolean	matchIgnoreCase(java.lang.String probe, java.lang.String pattern) Returns true, if the given probe string matches the given pattern.
protected boolean	matchReverse(java.lang.String patternStr, StringExaminer probeIterator)
boolean	multiCharWildcardMatchesEmptyString() Returns true, if this StringPattern allows empty strings at the position of the multi character wildcard ('*').
void	multiCharWildcardMatchesEmptyString(boolean newValue) sets whether or not this StringPattern allows empty strings at the position of the multi character wildcard ('*').
protected StringExaminer	newExaminer(java.lang.String str)
java.lang.String[]	reject(java.lang.String[] strings) Returns an array containing all of the given strings that do NOT match this pattern.
java.lang.String[]	select(java.lang.String[] strings) Returns an array containing all of the given strings that match this pattern.
protected java.lang.String[]	selectOrReject(java.lang.String[] strings, boolean select)
void	setDigitWildcardChar(char digitWildcard) Sets the given character as a wildcard character in this pattern to match only digits ('0'-'9').
void	setIgnoreCase(boolean newValue) Sets whether the pattern matching should ignore case or not
void	setMultiCharWildcard(char newValue) Sets the wildcard character that is used as placeholder for zero to many occurances of any character(s).
void	setPattern(java.lang.String newValue) Sets the pattern to a new value
void	setSingleCharWildcard(char newValue) Sets the wildcard character that is used as placeholder for a single occurance of any character.
protected boolean	skipAfter(StringExaminer examiner, java.lang.String matchString) Increments the given iterator up to the last character that matched the character sequence in the given matchString.
protected char	skipWildcards(StringExaminer iterator) Moves the iterator position to the next character that is no wildcard.
protected StringUtil	strUtil()
java.lang.String	toJSON() Returns a JSON string representation of this object.
java.lang.String	toString() Returns the pattern string.
protected java.lang.String	upToEnd(StringExaminer iterator)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_MULTICHAR_WILDCARD

protected static final char DEFAULT_MULTICHAR_WILDCARD

See Also:

Constant Field Values

DEFAULT_SINGLECHAR_WILDCARD

protected static final char DEFAULT_SINGLECHAR_WILDCARD

See Also:

Constant Field Values

SWITCH_ON

protected static final java.lang.String SWITCH_ON

See Also:

Constant Field Values

SWITCH_OFF

protected static final java.lang.String SWITCH_OFF

See Also:

Constant Field Values

Constructor Detail

StringPattern

public StringPattern(java.lang.String pattern,
                     boolean ignoreCase)

Initializes the new instance with the string pattern and the selection, if case should be ignored when comparing characters.

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

ignoreCase - Definition, if case sensitive character comparison or not.

See Also:

create(String, boolean)

StringPattern

public StringPattern(java.lang.String pattern)

Initializes the new instance with the string pattern. The default is case sensitive checking.

As an alternative see also StringPattern.create() method.

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

See Also:

create(String)

StringPattern

public StringPattern(java.lang.String pattern,
                     char digitWildcard)

Initializes the new instance with the string pattern and a digit wildcard character. The default is case sensitive checking.

Parameters:

pattern - The pattern to check against ( May contain '*', '?' wildcards and the digit wildcard )

digitWildcard - A wildcard character that stands as placeholder for digits

See Also:

create(String, char)

StringPattern

public StringPattern(java.lang.String pattern,
                     boolean ignoreCase,
                     char digitWildcard)

Initializes the new instance with the string pattern and the selection, if case should be ignored when comparing characters plus a wildcard character for digits.

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

ignoreCase - Definition, if case sensitive character comparison or not.

digitWildcard - A wildcard character that stands as placeholder for digits

See Also:

create(String, boolean, char)

Method Detail

create

public static StringPattern create(java.lang.String pattern,
                                   boolean ignoreCase)

Returns a new instance with the string pattern and the selection, if case should be ignored when comparing characters.
The option multiCharWildcardMatchesEmptyString will be initialized to true.

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

ignoreCase - Definition, if case sensitive character comparison or not.

create

public static StringPattern create(java.lang.String pattern,
                                   char digitWildcard)

Returns anew instance with the string pattern and a digit wildcard character. The default is case sensitive checking.
The option multiCharWildcardMatchesEmptyString will be initialized to true.

Parameters:

pattern - The pattern to check against ( May contain '*', '?' wildcards and the digit wildcard )

digitWildcard - A wildcard character that stands as placeholder for digits

create

public static StringPattern create(java.lang.String pattern,
                                   boolean ignoreCase,
                                   char digitWildcard)

Returns a new instance with the string pattern and the selection, if case should be ignored when comparing characters plus a wildcard character for digits.
It is also configured to match the wildcard '*' to empty strings.

Example:
StringPattern.create( "*London*Eye#", true, '#' ).matches( "londonEYE8" ) ==> true

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

ignoreCase - Definition, if case sensitive character comparison or not.

digitWildcard - A wildcard character that stands as placeholder for digits

match

public static boolean match(java.lang.String probe,
                            java.lang.String pattern)

Returns true, if the given probe string matches the given pattern.
The character comparison is done case sensitive.

Parameters:

probe - The string to check against the pattern.

pattern - The patter, that probably contains wildcards ( '*' or '?' )

matchIgnoreCase

public static boolean matchIgnoreCase(java.lang.String probe,
                                      java.lang.String pattern)

Returns true, if the given probe string matches the given pattern.
The character comparison is done ignoring upper/lower-case.

Parameters:

probe - The string to check against the pattern.

pattern - The patter, that probably contains wildcards ( '*' or '?' )

getDefaultMultiCharWildcard

public static char getDefaultMultiCharWildcard()

Returns the character that is used to specify any number of any character. The default is '*'.

getDefaultSingleCharWildcard

public static char getDefaultSingleCharWildcard()

Returns the character that is used to specify any single character. The default is '?'.

containsWildcard

public static boolean containsWildcard(java.lang.String aString)

Returns true if the given string contains a single or multi character wildcard. Of course this checks only the default wildcard characters.

Parameters:

aString - The string to check for wildcard characters

getIgnoreCase

public boolean getIgnoreCase()

Returns whether or not the pattern matching ignores upper and lower case

setIgnoreCase

public void setIgnoreCase(boolean newValue)

Sets whether the pattern matching should ignore case or not

getPattern

public java.lang.String getPattern()

Returns the pattern as string.

setPattern

public void setPattern(java.lang.String newValue)

Sets the pattern to a new value

create

public static StringPattern create(java.lang.String pattern)

Returns a new instance with the string pattern. The default is case sensitive checking.
The option multiCharWildcardMatchesEmptyString will be initialized to true.

Parameters:

pattern - The pattern to check against ( May contain '*' and '?' wildcards )

getSingleCharWildcard

public char getSingleCharWildcard()

Returns the wildcard character that is used as placeholder for a single occurance of any character.

setSingleCharWildcard

public void setSingleCharWildcard(char newValue)

Sets the wildcard character that is used as placeholder for a single occurance of any character.

getMultiCharWildcard

public char getMultiCharWildcard()

Returns the wildcard character that is used as placeholder for zero to many occurances of any character(s).

setMultiCharWildcard

public void setMultiCharWildcard(char newValue)

Sets the wildcard character that is used as placeholder for zero to many occurances of any character(s).

multiCharWildcardMatchesEmptyString

public boolean multiCharWildcardMatchesEmptyString()

Returns true, if this StringPattern allows empty strings at the position of the multi character wildcard ('*').

The default value is false.

multiCharWildcardMatchesEmptyString

public void multiCharWildcardMatchesEmptyString(boolean newValue)

sets whether or not this StringPattern allows empty strings at the position of the multi character wildcard ('*').

The default value is false.

matches

public boolean matches(java.lang.String probe)

Tests if a specified string matches the pattern.

Specified by:

matches in interface IObjectFilter<java.lang.String>

Specified by:

matches in interface IStringFilter

Parameters:

probe - The string to compare to the pattern

Returns:

true if and only if the probe matches the pattern, false otherwise.

select

public java.lang.String[] select(java.lang.String[] strings)

Returns an array containing all of the given strings that match this pattern.

Parameters:

strings - The strings to be matched against this pattern

reject

public java.lang.String[] reject(java.lang.String[] strings)

Returns an array containing all of the given strings that do NOT match this pattern.

Parameters:

strings - The strings to be matched against this pattern

asString

public java.lang.String asString()

Description copied from interface: IStringRepresentation

Returns the string representation of the implementing object.

Specified by:

asString in interface IStringRepresentation

toString

public java.lang.String toString()

Returns the pattern string.

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()

hasWildcard

public boolean hasWildcard()

Returns true if the pattern contains any '*' or '?' or digit wildcard wildcard character.

setDigitWildcardChar

public void setDigitWildcardChar(char digitWildcard)

Sets the given character as a wildcard character in this pattern to match only digits ('0'-'9').

Parameters:

digitWildcard - The placeholder character for digits

copy

public StringPattern copy()

Returns a copy of this pattern. The values of the copy are independent of the origin. That means, changes to the copy will have no impact on this string pattern.

equals

public boolean equals(java.lang.Object obj)

Returns true if the given object is equal to the receiver.

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(java.lang.Object)

hashCode

public int hashCode()

Returns a hash code value for the object.

Overrides:

hashCode in class java.lang.Object

See Also:

Object.hashCode()

appendAsJSONString

public void appendAsJSONString(java.lang.Appendable output)

Description copied from interface: IJSONConvertible

The receiver of this method must append its internal state as JSON string representation to the given buffer.

Specified by:

appendAsJSONString in interface IJSONConvertible

Parameters:

output - The output target to which to append the JSON string (must not be null).

toJSON

public java.lang.String toJSON()

Returns a JSON string representation of this object.

Specified by:

toJSON in interface IJSONConvertible

Returns:

JSON object: {"string1":"string2"}

eventuallyMatched

protected boolean eventuallyMatched(char probeCh,
                                    char patternCh,
                                    StringExaminer patternIterator)

hasDigitWildcard

protected boolean hasDigitWildcard()

digitWildcardChar

protected char digitWildcardChar()

skipWildcards

protected char skipWildcards(StringExaminer iterator)

Moves the iterator position to the next character that is no wildcard. Doesn't skip digit wildcards and single-char wildcards !

skipAfter

protected boolean skipAfter(StringExaminer examiner,
                            java.lang.String matchString)

Increments the given iterator up to the last character that matched the character sequence in the given matchString. Returns true, if the matchString was found, otherwise false.

Parameters:

matchString - The string to be found (must not contain *)

upToEnd

protected java.lang.String upToEnd(StringExaminer iterator)

matchReverse

protected boolean matchReverse(java.lang.String patternStr,
                               StringExaminer probeIterator)

charsAreEqual

protected boolean charsAreEqual(char probeChar,
                                char patternChar)

endReached

protected boolean endReached(char character)

endNotReached

protected boolean endNotReached(char character)

getPatternChar

protected char getPatternChar(StringExaminer patternIterator,
                              char probeCh)

newExaminer

protected StringExaminer newExaminer(java.lang.String str)

ignoreCaseAsString

protected java.lang.String ignoreCaseAsString()

selectOrReject

protected java.lang.String[] selectOrReject(java.lang.String[] strings,
                                            boolean select)

inspectString

protected java.lang.String inspectString()

strUtil

protected StringUtil strUtil()

digitWildcard

protected java.lang.Character digitWildcard()

digitWildcard

protected void digitWildcard(java.lang.Character newValue)