uk.org.ogsadai.activity.indexedfiles
Class SearchIndexedFileActivity

java.lang.Object
  |
  +--uk.org.ogsadai.activity.Activity
        |
        +--uk.org.ogsadai.activity.files.AbstractFileActivity
              |
              +--uk.org.ogsadai.activity.indexedfiles.SearchIndexedFileActivity

public class SearchIndexedFileActivity

extends AbstractFileActivity

Searches an index that has been built by the Jakarta Lucene full-text search engine. This activity produces two outputs, one containing the search results and the other containing the locations of each matching document. See the activity user documentation for more details: OGSADAI/doc/interaction/activities/indexedfiles/searchIndexedFileActivity.html

Author:

The OGSA-DAI Project Team

COPYRIGHT_NOTICE

private static final java.lang.String COPYRIGHT_NOTICE

Copyright statement

See Also:

Constant Field Values

LOG

private static final DAILogger LOG

Logger object for logging in this class

ANALYZER_CLASS_NAME

private static final java.lang.String ANALYZER_CLASS_NAME

Jakarta Lucene analyzer class name

See Also:

Constant Field Values

mQueryExpression

private java.lang.String mQueryExpression

Query expression (Jakarta Lucene)

mQuery

private org.apache.lucene.search.Query mQuery

Parsed query object

mIndex

private java.io.File mIndex

Index directory

mIndexName

private java.lang.String mIndexName

Name of index directory

mSearcher

private org.apache.lucene.search.IndexSearcher mSearcher

Searcher

mHits

private org.apache.lucene.search.Hits mHits

Matching documents

mCursor

private int mCursor

Cursor for matching documents

mDocumentLocationsOutput

private BlockWriter mDocumentLocationsOutput

Activity output 1 - location of each matching document.

mSearchResultsOutput

private BlockWriter mSearchResultsOutput

Activity output 2 - searchResult elements describing matching fields.

SearchIndexedFileActivity

public SearchIndexedFileActivity(org.w3c.dom.Element element)
                          throws ActivityCreationException,
                                 ActivitySpecificationException

initialise

public void initialise()
                throws ActivitySpecificationException,
                       ActivityExecutionException

Description copied from class: AbstractFileActivity

Gets the data resource accessor for the files data resource according to whether the users credentials permit this access.

Overrides:

initialise in class AbstractFileActivity

Throws:

ActivitySpecificationException - If the user is not permitted to access the resource.

ActivityExecutionException - If some internal problem occurs.

See Also:

Activity.initialise()

processFirst

protected void processFirst()

Description copied from class: Activity

This method is called during the first iteration of processing an activity. It can be overridden by subclasses to define some processing that should be done only once during the first iteration of the activity processing, for example evaluating a database query.

Overrides:

processFirst in class Activity

processBlock

protected void processBlock()

Description copied from class: Activity

Performs an iteration of the processing of an activity. This may involve reading a block of input data and writing a block of output data, or may involve some other kind of processing. When an activity is processed by the OGSA-DAI engine, this method will be invoked repeatedly until the activity either completes or stops due to an error or termination call. An implementation of this method should invoke the setCompleted method to indicate that processing is complete, or the setError method if an error occurs that will prevent the processing from completing.

Specified by:

processBlock in class Activity

cleanUp

protected void cleanUp()

Description copied from class: Activity

This method can be overridden by any Activity implementations that need to free up resources in the event of an error or intermediate termination of the activity processing.

Overrides:

cleanUp in class Activity