org.apache.uima.examples.cas

Class RegExAnnotator

java.lang.Object

org.apache.uima.analysis_component.AnalysisComponent_ImplBase

org.apache.uima.analysis_component.Annotator_ImplBase

org.apache.uima.analysis_component.CasAnnotator_ImplBase

org.apache.uima.examples.cas.RegExAnnotator

All Implemented Interfaces:

org.apache.uima.analysis_component.AnalysisComponent

public class RegExAnnotator
extends org.apache.uima.analysis_component.CasAnnotator_ImplBase

Annotator that find substrings of the input document that match regular expressions.

There are two ways to specify the regular expressions - via configuration parameters or via an external resource file.

This annotator takes the following optional configuration parameters:

• Patterns - array of Strings indicating regular expressions to match. The pattern language is described at http://java.sun.com/j2se/1.4.2/docs/api/java/util/regex/Pattern.html)
• TypeNames - array of Strings indicating names of Types to be created from the patterns.
• ContainingAnnotationTypes - an array of input annotation types. This annotator will only produce new annotations that are contained within existing annotaions of these types. (This is optional.)
• AnnotateEntireContainedAnnotation - When the ContainingAnnoationTypes parameter is specified, a value of true for this parameter will cause the entire containing annotation to be used as the span of the new annotation, rather than just the span of the regular expression match. This can be used to "classify" previously created annotations according to whether or not they contain text matching a regular expression.

The indices of the Patterns and TypeNames arrays correspond, so that a substring that matches Patterns[i] will result in an annotation of type TypeNames[i].

It is also possible to provide an external resource file that declares the annotation type names and the regular expressions to match. The annotator will look for this file under the resource key "PatternFile". The file format is as follows:

• Lines starting with # or whitepsace are ignored
• Lines starting with % indicate an annotation type
• All other lines are regular expressions, using the same syntax described for the Patterns configuration parameter.

If a regular expression is matched, it will be annotated with the last annotation type declared (the nearest preceding line starting with %).

Field Summary

Fields

Modifier and Type	Field and Description
static String	MESSAGE_DIGEST

Constructor Summary

Constructors

Constructor and Description
RegExAnnotator()

Method Summary

Modifier and Type	Method and Description
protected int[]	getRangesToAnnotate(org.apache.uima.cas.CAS aCAS) Utility method that determines which subranges of the document text should be annotated by this annotator.
void	initialize(org.apache.uima.UimaContext aContext) Performs any startup tasks required by this annotator.
void	process(org.apache.uima.cas.CAS aCAS) Invokes this annotator's analysis logic.
void	typeSystemInit(org.apache.uima.cas.TypeSystem aTypeSystem) Acquires references to CAS Type and Feature objects that are later used during the process(CAS) method.

Methods inherited from class org.apache.uima.analysis_component.CasAnnotator_ImplBase

getRequiredCasInterface, process

Methods inherited from class org.apache.uima.analysis_component.Annotator_ImplBase

getCasInstancesRequired, hasNext, next

Methods inherited from class org.apache.uima.analysis_component.AnalysisComponent_ImplBase

batchProcessComplete, collectionProcessComplete, destroy, getContext, getLogger, getResultSpecification, reconfigure, setResultSpecification

Methods inherited from class java.lang.Object

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

Field Detail

MESSAGE_DIGEST

public static final String MESSAGE_DIGEST

See Also:

Constant Field Values

Constructor Detail

RegExAnnotator

public RegExAnnotator()

Method Detail

initialize

public void initialize(org.apache.uima.UimaContext aContext)
                throws org.apache.uima.resource.ResourceInitializationException

Performs any startup tasks required by this annotator. This implementation reads the configuration parmaeters and compiles the regular expressions.

Specified by:

initialize in interface org.apache.uima.analysis_component.AnalysisComponent

Overrides:

initialize in class org.apache.uima.analysis_component.AnalysisComponent_ImplBase

Throws:

org.apache.uima.resource.ResourceInitializationException

See Also:

AnalysisComponent_ImplBase.initialize(UimaContext)

typeSystemInit

public void typeSystemInit(org.apache.uima.cas.TypeSystem aTypeSystem)
                    throws org.apache.uima.analysis_engine.AnalysisEngineProcessException

Acquires references to CAS Type and Feature objects that are later used during the process(CAS) method.

Overrides:

typeSystemInit in class org.apache.uima.analysis_component.CasAnnotator_ImplBase

Throws:

org.apache.uima.analysis_engine.AnalysisEngineProcessException

See Also:

CasAnnotator_ImplBase.typeSystemInit(TypeSystem)

process

public void process(org.apache.uima.cas.CAS aCAS)
             throws org.apache.uima.analysis_engine.AnalysisEngineProcessException

Invokes this annotator's analysis logic. This annotator uses the java regular expression package to find annotations using the regular expressions defined by its configuration parameters.

Specified by:

process in class org.apache.uima.analysis_component.CasAnnotator_ImplBase

Parameters:

aCAS - the CAS to process

Throws:

org.apache.uima.analysis_engine.AnalysisEngineProcessException - if a failure occurs during processing.

See Also:

CasAnnotator_ImplBase.process(CAS)

getRangesToAnnotate

protected int[] getRangesToAnnotate(org.apache.uima.cas.CAS aCAS)

Utility method that determines which subranges of the document text should be annotated by this annotator. This is done as follows:

• If mContainingAnnotationTypes is null, the entire document is eligible for annotation.
• If mContainingAnnotationTypes is not null, then each of its elements is expected to be an Annotation Type name. The CAS is queried for existing annotations of any of these Types, and the only subranges of the document eligible for annotation are those subranges contained within such annotations.

Parameters:

aCAS - CAS currently being processed

Returns:

an array of integers indicating the document subranges eligible for annotation. Begin and end positions of the subranges are stored in successive elements of the array. For example, elements 0 and 1 are the start and end of the first subrange; elements 2 and 3 are the start and end of the second subrange, and so on.