org.apache.oro.text

类 GenericPatternCache

java.lang.Object

org.apache.oro.text.GenericPatternCache

所有已实现的接口:

PatternCache

直接已知子类:

PatternCacheFIFO, PatternCacheFIFO2, PatternCacheLRU, PatternCacheRandom

public abstract class GenericPatternCache
extends Object
implements PatternCache

This is the base class for all cache implementations provided in the org.apache.oro.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.

从以下版本开始:

1.0

版本:

@version@

另请参阅:

PatternCache, PatternCacheLRU, PatternCacheFIFO, PatternCacheFIFO2, PatternCacheRandom

字段概要

字段

限定符和类型	字段和说明
static int	DEFAULT_CAPACITY The default capacity to be used by the GenericPatternCache subclasses provided with this package.

方法概要

限定符和类型	方法和说明
Pattern	addPattern(String expression) Same as calling addPattern(expression, 0);
Pattern	addPattern(String expression, int options) Adds a pattern to the cache and returns the compiled pattern.
int	capacity() Returns the maximum number of patterns that can be cached at one time.
Pattern	getPattern(String expression) Same as calling getPattern(expression, 0)
Pattern	getPattern(String expression, int options) This method fetches a pattern from the cache.
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.

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

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.

另请参阅:

常量字段值

方法详细资料

addPattern

public final 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.

指定者:

addPattern 在接口中 PatternCache

参数:

expression - The regular expression to add to the cache.

options - The compilation options to use when compiling the expression.

返回:

The Pattern corresponding to the String representation of the regular expression.

抛出:

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

addPattern

public final Pattern addPattern(String expression)
                         throws MalformedPatternException

Same as calling

 addPattern(expression, 0);
 

指定者:

addPattern 在接口中 PatternCache

参数:

expression - The regular expression to add to the cache.

返回:

The Pattern corresponding to the String representation of the regular expression.

抛出:

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

getPattern

public final 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.

指定者:

getPattern 在接口中 PatternCache

参数:

expression - The regular expression to fetch from the cache in compiled form.

options - The compilation options to use when compiling the expression.

返回:

The Pattern corresponding to the String representation of the regular expression.

抛出:

MalformedCachePatternException - If there is an error in compiling the regular expression.

getPattern

public final Pattern getPattern(String expression)
                         throws MalformedCachePatternException

Same as calling

 getPattern(expression, 0)
 

指定者:

getPattern 在接口中 PatternCache

参数:

expression - The regular expression to fetch from the cache in compiled form.

返回:

The Pattern corresponding to the String representation of the regular expression.

抛出:

MalformedCachePatternException - If there is an error in compiling the regular expression.

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.

指定者:

size 在接口中 PatternCache

返回:

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.

指定者:

capacity 在接口中 PatternCache

返回:

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