Package org.codehaus.plexus.interpolation

Class RegexBasedInterpolator

java.lang.Object

org.codehaus.plexus.interpolation.RegexBasedInterpolator

All Implemented Interfaces:

BasicInterpolator, Interpolator

public class RegexBasedInterpolator
extends 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.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DEFAULT_REGEXP

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	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.
List	getFeedback()	Return any feedback messages and errors that were generated - but suppressed - during the interpolation process.
String	interpolate(String input)	See interpolate(String, String, RecursionInterceptor).
String	interpolate(String input, String thisPrefixPattern)	See interpolate(String, String, RecursionInterceptor).
String	interpolate(String input, 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.
String	interpolate(String input, RecursionInterceptor recursionInterceptor)	See interpolate(String, String, RecursionInterceptor).
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 Details

DEFAULT_REGEXP

public static final String DEFAULT_REGEXP

See Also:

• Constant Field Values

Constructor Details

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(String startRegex,
 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(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(String startRegex,
 String endRegex,
 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 Details

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

Parameters:

valueSource - ValueSource.

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

Parameters:

valueSource - ValueSource.

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

Parameters:

postProcessor - InterpolationPostProcessor.

removePostProcessor

public void removePostProcessor(InterpolationPostProcessor postProcessor)

Remove the given post-processor.

Specified by:

removePostProcessor in interface Interpolator

Parameters:

postProcessor - InterpolationPostProcessor.

interpolate

public String interpolate(String input,
 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.

Returns:

interpolated string.

Throws:

InterpolationException - in case of an error.

getFeedback

public 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 String interpolate(String input,
 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.

Returns:

interpolated string.

Throws:

InterpolationException - in case of an error.

interpolate

public String interpolate(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

Returns:

the interpolated string.

Throws:

InterpolationException - in case of an error.

interpolate

public String interpolate(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.

Returns:

the interpolated string.

Throws:

InterpolationException - in case of an error.

isReusePatterns

public boolean isReusePatterns()

setReusePatterns

public void setReusePatterns(boolean reusePatterns)

isCacheAnswers

public boolean isCacheAnswers()

Specified by:

isCacheAnswers in interface Interpolator

Returns:

state of the cacheAnswers

setCacheAnswers

public void setCacheAnswers(boolean cacheAnswers)

Specified by:

setCacheAnswers in interface Interpolator

Parameters:

cacheAnswers - true/false.

clearAnswers

public void clearAnswers()

Specified by:

clearAnswers in interface Interpolator