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Class com.oroinc.text.GenericPatternCache

java.lang.Object
   |
   +----com.oroinc.text.GenericPatternCache

public abstract class GenericPatternCache
extends Object
implements PatternCache

This is the base class for all cache implementations provided in the com.oroinc.text package. Although 4 subclasses of GenericPatternCache are provided with this package, users may not derive subclasses from this class. Rather, users should create their own implmentations of the PatternCache interface.

See Also:: PatternCache, PatternCacheLRU, PatternCacheFIFO, PatternCacheFIFO2, PatternCacheRandom

DEFAULT_CAPACITY: The default capacity to be used by the GenericPatternCache subclasses provided with this package.

addPattern(String)

Same as calling

 addPattern(expression, 0);

addPattern(String, int)

Adds a pattern to the cache and returns the compiled pattern.

capacity()

Returns the maximum number of patterns that can be cached at one time.

getPattern(String)

Same as calling

 getPattern(expression, 0)

getPattern(String, int)

This method fetches a pattern from the cache.

size()

Returns the number of elements in the cache, not to be confused with the capacity() which returns the number of elements that can be held in the cache at one time.

DEFAULT_CAPACITY

 public static final int DEFAULT_CAPACITY

The default capacity to be used by the GenericPatternCache subclasses provided with this package. Its value is 20.

addPattern

 public final synchronized Pattern addPattern(String expression,
                                              int options) throws MalformedPatternException

Adds a pattern to the cache and returns the compiled pattern. This method is in principle almost identical to getPattern() except for the fact that it throws a MalformedPatternException if an expression cannot be compiled.

addPattern() is meant to be used when you expressly intend to add an expression to the cache and is useful for front-loading a cache with expressions before use. If the expression added does not already exist in the cache, it is compiled, added to the cache, and returned. If the compiled expression is already in the cache, it is simply returned.

The expected behavior of this method should be to start replacing patterns in the cache only after the cache has been filled to capacity.

Parameters:: expression - The regular expression to add to the cache.; options - The compilation options to use when compiling the expression.
Returns:: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedPatternException: If there is an error in compiling the regular expression.

addPattern

 public final synchronized Pattern addPattern(String expression) throws MalformedPatternException

Same as calling

 addPattern(expression, 0);

Throws: MalformedPatternException: If there is an error in compiling the regular expression.

getPattern

 public final synchronized Pattern getPattern(String expression,
                                              int options) throws MalformedCachePatternException

This method fetches a pattern from the cache. It is nearly identical to addPattern() except that it doesn't throw a MalformedPatternException. If the pattern is not in the cache, it is compiled, placed in the cache, and returned. If the pattern cannot be compiled successfully, it throws a MalformedCachePatternException. Note that this exception is derived from RuntimeException, which means you are NOT forced to catch it by the compiler. Please refer to MalformedCachePatternException for a discussion of when you should and shouldn't catch this exception.

Parameters:: expression - The regular expression to fetch from the cache in compiled form.; options - The compilation options to use when compiling the expression.
Returns:: The Pattern corresponding to the String representation of the regular expression.
Throws: MalformedCachePatternException: If there is an error in compiling the regular expression.

getPattern

 public final synchronized Pattern getPattern(String expression) throws MalformedCachePatternException

Same as calling

 getPattern(expression, 0)

size

 public final int size()

Returns the number of elements in the cache, not to be confused with the capacity() which returns the number of elements that can be held in the cache at one time.

Returns:: The current size of the cache (i.e., the number of elements currently cached).

capacity

 public final int capacity()

Returns the maximum number of patterns that can be cached at one time.

Returns:: The maximum number of patterns that can be cached at one time.

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