org.codehaus.plexus.interpolation

Class RegexBasedInterpolator

java.lang.Object

org.codehaus.plexus.interpolation.RegexBasedInterpolator

All Implemented Interfaces:

BasicInterpolator, Interpolator

public class RegexBasedInterpolator
extends java.lang.Object
implements Interpolator

Expansion of the original RegexBasedInterpolator, found in plexus-utils, this interpolator provides options for setting custom prefix/suffix regex parts, and includes a RecursionInterceptor parameter in its interpolate(..) call, to allow the detection of cyclical expression references.

Version:

$Id$

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	cacheAnswers
private java.util.Map<java.lang.String,java.util.regex.Pattern>	compiledPatterns the key is the regex the value is the Pattern At the class construction time the Map will contains the default Pattern
static java.lang.String	DEFAULT_REGEXP
private java.lang.String	endRegex
private java.util.Map	existingAnswers
private java.util.List<InterpolationPostProcessor>	postProcessors
private boolean	reusePatterns
private java.lang.String	startRegex
private java.util.List<ValueSource>	valueSources

Constructor Summary

Constructors

Constructor and Description
RegexBasedInterpolator() Setup a basic interpolator.
RegexBasedInterpolator(boolean reusePatterns)
RegexBasedInterpolator(java.util.List valueSources) Setup a basic interpolator with the specified list of value sources.
RegexBasedInterpolator(java.lang.String startRegex, java.lang.String endRegex) Setup an interpolator with no value sources, and the specified regex pattern prefix and suffix in place of the default one.
RegexBasedInterpolator(java.lang.String startRegex, java.lang.String endRegex, java.util.List valueSources) Setup an interpolator with the specified value sources, and the specified regex pattern prefix and suffix in place of the default one.

Method Summary

Modifier and Type	Method and Description
void	addPostProcessor(InterpolationPostProcessor postProcessor) Add a new post-processor to handle final processing after recursively-interpolated value is determined.
void	addValueSource(ValueSource valueSource) Add a new ValueSource to the stack used to resolve expressions in this interpolator instance.
void	clearAnswers()
void	clearFeedback() Clear the feedback messages from previous interpolate(..) calls.
java.util.List	getFeedback() Return any feedback messages and errors that were generated - but suppressed - during the interpolation process.
private java.util.regex.Pattern	getPattern(java.lang.String regExp)
java.lang.String	interpolate(java.lang.String input) See interpolate(String, String, RecursionInterceptor).
java.lang.String	interpolate(java.lang.String input, RecursionInterceptor recursionInterceptor) See interpolate(String, String, RecursionInterceptor).
private java.lang.String	interpolate(java.lang.String input, RecursionInterceptor recursionInterceptor, java.util.regex.Pattern expressionPattern, int realExprGroup) Entry point for recursive resolution of an expression and all of its nested expressions.
java.lang.String	interpolate(java.lang.String input, java.lang.String thisPrefixPattern) See interpolate(String, String, RecursionInterceptor).
java.lang.String	interpolate(java.lang.String input, java.lang.String thisPrefixPattern, RecursionInterceptor recursionInterceptor) Attempt to resolve all expressions in the given input string, using the given pattern to first trim an optional prefix from each expression.
boolean	isCacheAnswers()
boolean	isReusePatterns()
void	removePostProcessor(InterpolationPostProcessor postProcessor) Remove the given post-processor.
void	removeValuesSource(ValueSource valueSource) Remove the specified ValueSource from the stack used to resolve expressions in this interpolator instance.
void	setCacheAnswers(boolean cacheAnswers)
void	setReusePatterns(boolean reusePatterns)

Methods inherited from class java.lang.Object

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

Field Detail

startRegex

private java.lang.String startRegex

endRegex

private java.lang.String endRegex

existingAnswers

private java.util.Map existingAnswers

valueSources

private java.util.List<ValueSource> valueSources

postProcessors

private java.util.List<InterpolationPostProcessor> postProcessors

reusePatterns

private boolean reusePatterns

cacheAnswers

private boolean cacheAnswers

DEFAULT_REGEXP

public static final java.lang.String DEFAULT_REGEXP

See Also:

Constant Field Values

compiledPatterns

private java.util.Map<java.lang.String,java.util.regex.Pattern> compiledPatterns

the key is the regex the value is the Pattern At the class construction time the Map will contains the default Pattern

Constructor Detail

RegexBasedInterpolator

public RegexBasedInterpolator()

Setup a basic interpolator.
NOTE: You will have to call addValueSource(ValueSource) at least once if you use this constructor!

RegexBasedInterpolator

public RegexBasedInterpolator(boolean reusePatterns)

Parameters:

reusePatterns - already compiled patterns will be reused

RegexBasedInterpolator

public RegexBasedInterpolator(java.lang.String startRegex,
                              java.lang.String endRegex)

Setup an interpolator with no value sources, and the specified regex pattern prefix and suffix in place of the default one.
NOTE: You will have to call addValueSource(ValueSource) at least once if you use this constructor!

Parameters:

startRegex - start of the regular expression to use

endRegex - end of the regular expression to use

RegexBasedInterpolator

public RegexBasedInterpolator(java.util.List valueSources)

Setup a basic interpolator with the specified list of value sources.

Parameters:

valueSources - The list of value sources to use

RegexBasedInterpolator

public RegexBasedInterpolator(java.lang.String startRegex,
                              java.lang.String endRegex,
                              java.util.List valueSources)

Setup an interpolator with the specified value sources, and the specified regex pattern prefix and suffix in place of the default one.

Parameters:

startRegex - start of the regular expression to use

endRegex - end of the regular expression to use

valueSources - The list of value sources to use

Method Detail

addValueSource

public void addValueSource(ValueSource valueSource)

Add a new ValueSource to the stack used to resolve expressions in this interpolator instance.

Specified by:

addValueSource in interface Interpolator

removeValuesSource

public void removeValuesSource(ValueSource valueSource)

Remove the specified ValueSource from the stack used to resolve expressions in this interpolator instance.

Specified by:

removeValuesSource in interface Interpolator

addPostProcessor

public void addPostProcessor(InterpolationPostProcessor postProcessor)

Add a new post-processor to handle final processing after recursively-interpolated value is determined.

Specified by:

addPostProcessor in interface Interpolator

removePostProcessor

public void removePostProcessor(InterpolationPostProcessor postProcessor)

Remove the given post-processor.

Specified by:

removePostProcessor in interface Interpolator

interpolate

public java.lang.String interpolate(java.lang.String input,
                                    java.lang.String thisPrefixPattern,
                                    RecursionInterceptor recursionInterceptor)
                             throws InterpolationException

Attempt to resolve all expressions in the given input string, using the given pattern to first trim an optional prefix from each expression. The supplied recursion interceptor will provide protection from expression cycles, ensuring that the input can be resolved or an exception is thrown.

Specified by:

interpolate in interface Interpolator

Parameters:

input - The input string to interpolate

thisPrefixPattern - An optional pattern that should be trimmed from the start of any expressions found in the input.

recursionInterceptor - Used to protect the interpolation process from expression cycles, and throw an exception if one is detected.

Throws:

InterpolationException

getPattern

private java.util.regex.Pattern getPattern(java.lang.String regExp)

interpolate

private java.lang.String interpolate(java.lang.String input,
                                     RecursionInterceptor recursionInterceptor,
                                     java.util.regex.Pattern expressionPattern,
                                     int realExprGroup)
                              throws InterpolationException

Entry point for recursive resolution of an expression and all of its nested expressions.

Throws:

InterpolationException

getFeedback

public java.util.List getFeedback()

Return any feedback messages and errors that were generated - but suppressed - during the interpolation process. Since unresolvable expressions will be left in the source string as-is, this feedback is optional, and will only be useful for debugging interpolation problems.

Specified by:

getFeedback in interface Interpolator

Returns:

a List that may be interspersed with String and Throwable instances.

clearFeedback

public void clearFeedback()

Clear the feedback messages from previous interpolate(..) calls.

Specified by:

clearFeedback in interface Interpolator

interpolate

public java.lang.String interpolate(java.lang.String input,
                                    java.lang.String thisPrefixPattern)
                             throws InterpolationException

See interpolate(String, String, RecursionInterceptor).
This method triggers the use of a SimpleRecursionInterceptor instance for protection against expression cycles.

Specified by:

interpolate in interface Interpolator

Parameters:

input - The input string to interpolate

thisPrefixPattern - An optional pattern that should be trimmed from the start of any expressions found in the input.

Throws:

InterpolationException

interpolate

public java.lang.String interpolate(java.lang.String input)
                             throws InterpolationException

See interpolate(String, String, RecursionInterceptor).
This method triggers the use of a SimpleRecursionInterceptor instance for protection against expression cycles. It also leaves empty the expression prefix which would otherwise be trimmed from expressions. The result is that any detected expression will be resolved as-is.

Specified by:

interpolate in interface BasicInterpolator

Parameters:

input - The input string to interpolate

Throws:

InterpolationException

interpolate

public java.lang.String interpolate(java.lang.String input,
                                    RecursionInterceptor recursionInterceptor)
                             throws InterpolationException

See interpolate(String, String, RecursionInterceptor).
This method leaves empty the expression prefix which would otherwise be trimmed from expressions. The result is that any detected expression will be resolved as-is.

Specified by:

interpolate in interface BasicInterpolator

Parameters:

input - The input string to interpolate

recursionInterceptor - Used to protect the interpolation process from expression cycles, and throw an exception if one is detected.

Throws:

InterpolationException

isReusePatterns

public boolean isReusePatterns()

setReusePatterns

public void setReusePatterns(boolean reusePatterns)

isCacheAnswers

public boolean isCacheAnswers()

Specified by:

isCacheAnswers in interface Interpolator

setCacheAnswers

public void setCacheAnswers(boolean cacheAnswers)

Specified by:

setCacheAnswers in interface Interpolator

clearAnswers

public void clearAnswers()

Specified by:

clearAnswers in interface Interpolator