com.sptci.prevayler
Class SearchSystem

java.lang.Object
  com.sptci.prevayler.StorageSystem
      com.sptci.prevayler.IndexSystem
          com.sptci.prevayler.ConstraintSystem
              com.sptci.prevayler.SearchSystem

All Implemented Interfaces:

AbstractDatabase<PrevalentObject>, DatabaseSystem, Serializable

Direct Known Subclasses:

ObjectGraphSystem

abstract class SearchSystem
extends ConstraintSystem

Abstracts all the full-text search indexing and de-indexing operations for the prevalent system. Indexing is performed using Lucene.

Note:The field values are converted to String using the Object.toString() method to retrieve the content to index. To ensure meaningful indices ensure that the fields annotated return meaningful values.

© Copyright 2008 Sans Pareil Technologies, Inc.

Since:

Release 0.3.0

Version:

$Id: SearchSystem.java 23 2008-11-24 19:49:55Z sptrakesh $

Author:

Rakesh Vidyadharan 2008-11-12

Nested Class Summary

private static class

SearchSystem.Closer A thread used as a shutdown hook to the JVM to close the writer and other lucene resources.

Nested classes/interfaces inherited from class com.sptci.prevayler.StorageSystem

StorageSystem.TaskQueue

Field Summary

static String	CLASS_FIELD The name of the field in the indexed document that stores the class name.
(package private) static String	DOCUMENT_ID_FIELD The name of the field in the indexed document that stores the unique document id.
static String	OBJECT_ID_FIELD The name of the field in the indexed document that stores the object id.
protected static org.apache.lucene.index.IndexReader	reader The index reader instance to use to read the index.
static int	SAVE_COUNT The number or index updates before a IndexWriter.commit() is invoked.
private int	saveCount A counter to ensure that the IndexWriter.commit() method is called periodically.
protected static org.apache.lucene.search.IndexSearcher	searcher The index searcher instance to use to search documents.
static char	SEPARATOR_CHAR The separator character used to delimit composite index field names.
private static long	serialVersionUID
protected static org.apache.lucene.index.IndexWriter	writer The index writer instance to use to create/delete documents.

Fields inherited from class com.sptci.prevayler.StorageSystem

logger

Constructor Summary

SearchSystem()

Method Summary

private void	commit() Commit pending writes to the index and refresh the reader.
private org.apache.lucene.document.Document	createDocument(PrevalentObject object) Create a document to store the full-text indices for the specified object.
private String	getDocumentId(PrevalentObject object) Return the unique document id for the index document representing the specified prevalent object.
private boolean	hasIndices(PrevalentObject object) Determine whether the prevalent object has any full-text search indices specified.
protected void	index(PrevalentObject object) Over-ridden to process search annotations for the object.
private void	indexClass(PrevalentObject object, org.apache.lucene.document.Document doc) Add full-text search indices for composite indices defined at the class level.
private void	indexFields(PrevalentObject object, org.apache.lucene.document.Document doc) Add full=text search indices for any fields annotated as searchable in the prevalent object.
private void	indexSearchable(PrevalentObject object, org.apache.lucene.document.Document doc, Searchable index) Process the Searchable annotation for the specified prevalent object class.
private void	indexSearchables(PrevalentObject object, org.apache.lucene.document.Document doc) Process the Searchables annotation for the specified prevalent object class.
protected void	remove(PrevalentObject object) Over-ridden to remove the search index for the specified prevalent object.
private void	save(PrevalentObject object, org.apache.lucene.document.Document document) Save the specified document to the index writer.
protected void	search(org.apache.lucene.search.Query query, org.apache.lucene.search.Filter filter, int count, org.apache.lucene.search.Sort sort, Collection<PrevalentObject> collection) Search the search indices and retrieve all the objects (regardless of type) that match the specified query and return up to the specified number of results.

Methods inherited from class com.sptci.prevayler.ConstraintSystem

checkFields, checkUnique, checkUnique, indexClass, indexFields, preAdd, preDelete, preDelete

Methods inherited from class com.sptci.prevayler.StorageSystem

generateOid, getIndexStorage, getIndexStorage, getPrimaryStorage, getPrimaryStorage, getReferenceStorage, getReferenceStorage, getRelationStorage, getRelationStorage, getTaskQueue

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.sptci.prevayler.DatabaseSystem

delete, save

Methods inherited from interface com.sptci.prevayler.AbstractDatabase

count, fetch, fetch, fetch, fetchIntersection, fetchUnion, search

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

writer

protected static final transient org.apache.lucene.index.IndexWriter writer

The index writer instance to use to create/delete documents.

reader

protected static transient org.apache.lucene.index.IndexReader reader

The index reader instance to use to read the index.

searcher

protected static transient org.apache.lucene.search.IndexSearcher searcher

The index searcher instance to use to search documents.

DOCUMENT_ID_FIELD

static final String DOCUMENT_ID_FIELD

The name of the field in the indexed document that stores the unique document id.

See Also:

Constant Field Values

CLASS_FIELD

public static final String CLASS_FIELD

The name of the field in the indexed document that stores the class name. "class"

See Also:

Constant Field Values

OBJECT_ID_FIELD

public static final String OBJECT_ID_FIELD

The name of the field in the indexed document that stores the object id. "objectId"

See Also:

Constant Field Values

SEPARATOR_CHAR

public static final char SEPARATOR_CHAR

The separator character used to delimit composite index field names. 35

See Also:

Constant Field Values

SAVE_COUNT

public static final int SAVE_COUNT

The number or index updates before a IndexWriter.commit() is invoked. Invoked only in batches to avoid expensive operation on each transaction.

saveCount

private int saveCount

A counter to ensure that the IndexWriter.commit() method is called periodically.

Constructor Detail

SearchSystem

SearchSystem()

Method Detail

index

protected void index(PrevalentObject object)
              throws PrevalentException

Over-ridden to process search annotations for the object. If full=text search has been specified, create a Document that holds all the indexed fields in the prevalent object.

Overrides:

index in class IndexSystem

Parameters:

object - The prevalent object to add query support for.

Throws:

PrevalentException - If errors are encountered while fetching the values of the fields in prevalent object.

See Also:

IndexSystem.indexFields(com.sptci.prevayler.PrevalentObject), IndexSystem.indexClass(com.sptci.prevayler.PrevalentObject)

remove

protected void remove(PrevalentObject object)
               throws PrevalentException

Over-ridden to remove the search index for the specified prevalent object. Over-ridden to remove the references to the prevalent object being removed from the system from the reference storage container. Remove the index for the specified prevalent object. This is typically called prior to deleting a prevalent object.

Overrides:

remove in class ConstraintSystem

Parameters:

object - The prevalent object to de-index.

Throws:

PrevalentException - If errors are encountered while removing the index for the prevalent object.

hasIndices

private boolean hasIndices(PrevalentObject object)
                    throws PrevalentException

Determine whether the prevalent object has any full-text search indices specified.

Parameters:

object - The prevalent object to check.

Returns:

Return true if any search indices have been specified.

Throws:

PrevalentException - If errors are encountered while reflecting upon the annotations in the prevalent object.

createDocument

private org.apache.lucene.document.Document createDocument(PrevalentObject object)

Create a document to store the full-text indices for the specified object.

Parameters:

object - The prevalent object to index.

Returns:

The new document instance.

See Also:

getDocumentId(PrevalentObject)

getDocumentId

private String getDocumentId(PrevalentObject object)

Return the unique document id for the index document representing the specified prevalent object.

Parameters:

object - The prevalent object for which the document id is to be retrieved.

Returns:

The unique document identifier.

indexFields

private void indexFields(PrevalentObject object,
                         org.apache.lucene.document.Document doc)
                  throws IllegalAccessException

Add full=text search indices for any fields annotated as searchable in the prevalent object.

Parameters:

object - The prevalent object whose fields are to be indexed.

doc - The document to which indices are to be added.

Throws:

IllegalAccessException - If errors are encountered while reflecting upon the fields in the prevalent object.

indexClass

private void indexClass(PrevalentObject object,
                        org.apache.lucene.document.Document doc)
                 throws IllegalAccessException

Add full-text search indices for composite indices defined at the class level. Composite index field names are assigned as a concatenation of the names of the fields that comprise the index if no value is specified for Searchable.name(). The concatenated names are delimited by the SEPARATOR_CHAR.

Parameters:

object - The prevalent object whose composite fields are to be indexed.

doc - The document to which indices are to be added.

Throws:

IllegalAccessException - If errors are encountered while reflecting upon the fields in the prevalent object.

See Also:

indexSearchables(PrevalentObject, org.apache.lucene.document.Document), indexSearchable(PrevalentObject, org.apache.lucene.document.Document, com.sptci.prevayler.annotations.Searchable)

indexSearchables

private void indexSearchables(PrevalentObject object,
                              org.apache.lucene.document.Document doc)
                       throws IllegalAccessException

Process the Searchables annotation for the specified prevalent object class. Create the composite indices for the specified array of composite indices.

Parameters:

object - The prevalent object whose composite fields are to be indexed.

doc - The document to which indices are to be added.

Throws:

IllegalAccessException - If errors are encountered while fetching the field values of the prevalent object.

indexSearchable

private void indexSearchable(PrevalentObject object,
                             org.apache.lucene.document.Document doc,
                             Searchable index)
                      throws IllegalAccessException

Process the Searchable annotation for the specified prevalent object class. Create the composite index for the array of fields.

Parameters:

object - The prevalent object whose composite fields are to be indexed.

doc - The document to which indices are to be added.

index - The searchable index annotation to process.

Throws:

IllegalAccessException - If errors are encountered while fetching the field values of the prevalent object.

save

private void save(PrevalentObject object,
                  org.apache.lucene.document.Document document)
           throws IOException

Save the specified document to the index writer. Delete an existing document instance if it exists.

Parameters:

object - The prevalent object that is being indexed.

document - The new document to add to the index.

Throws:

IOException - If errors are encountered while saving the document.

See Also:

IndexWriter.updateDocument( org.apache.lucene.index.Term, org.apache.lucene.document.Document), commit()

commit

private void commit()
             throws IOException

Commit pending writes to the index and refresh the reader.

Throws:

IOException - If errors are encountered while saving the document.

search

protected void search(org.apache.lucene.search.Query query,
                      org.apache.lucene.search.Filter filter,
                      int count,
                      org.apache.lucene.search.Sort sort,
                      Collection<PrevalentObject> collection)
               throws Exception

Search the search indices and retrieve all the objects (regardless of type) that match the specified query and return up to the specified number of results.

Parameters:

query - The query to execute.

filter - The filter to apply to the search.

count - The maximum number of results to return.

sort - The sort fields to apply to the results.

collection - The collection to which matching objects are added.

Throws:

Exception - If errors are encountered while reconstituting the prevalent objects or executing the search.

See Also:

AbstractDatabase.fetch(Class, Object)