prajna.structure.accessor

Class SolrAccessor

java.lang.Object

prajna.structure.AbstractDataAccessor<DataRecord,DataRecord>

prajna.structure.accessor.RecordAccessor

prajna.structure.accessor.SolrAccessor

All Implemented Interfaces:

DataAccessor<DataRecord,DataRecord>

public class SolrAccessor
extends RecordAccessor

Implementation of a SemanticAccessor which accesses its data from a Solr instance. This class builds datasets, graphs, and trees based upon the configuration parameters and Solr schemas.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
SolrAccessor()

Method Summary

Methods

Modifier and Type	Method and Description
protected DataRecord	createReferenceNode(DataRecord referrer, java.lang.String name, FieldDesc<?> desc) Derive a data record for inclusion in a graph, tree, or other structure based upon a referring node.
boolean	extendGraph(java.lang.String graphName, Graph<DataRecord,DataRecord> graph, DataRecord node) Extend the given graph around the specified node.
boolean	extendTree(java.lang.String treeName, Tree<DataRecord> tree, DataRecord node) Extend the given tree around the specified node.
protected java.util.Set<DataRecord>	retrieveRecords(DataTemplate template) Retrieve a set of data records for a particular DataTemplate.
void	setInitParameters(java.util.Map<java.lang.String,java.lang.String> parameters) Set any initialization parameters required by this data accessor.
void	setQuery(java.lang.String queryString) Set the query string used to retrieve records.

Methods inherited from class prajna.structure.accessor.RecordAccessor

addFieldHandler, addToGraph, addToTree, getDataset, getFieldHandler, getGraph, getGrid, getMaxRecords, getReasoner, getStructureReasoners, getTree, setMaxRecords, setReasoner, setReasoner

Methods inherited from class prajna.structure.AbstractDataAccessor

addStructure, addTemplate, getDatasetNames, getGraphNames, getGridNames, getSpec, getStructureType, getTemplate, getTemplateNames, getTreeNames, setConfig, setConfigFile, setConfigFile

Methods inherited from class java.lang.Object

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

Constructor Detail

SolrAccessor

public SolrAccessor()

Method Detail

createReferenceNode

protected DataRecord createReferenceNode(DataRecord referrer,
                             java.lang.String name,
                             FieldDesc<?> desc)

Derive a data record for inclusion in a graph, tree, or other structure based upon a referring node. This method is used when a data structure contains a reference to a record which is not available. For instance, this method is called when a graph contains an edge which refers to a node which is not in the current set of graph nodes, and cannot be retrieved from the underlying data source.

Overrides:

createReferenceNode in class RecordAccessor

Parameters:

referrer - the data record containing the reference to the node

name - The name for the new Data Record. This should be one of the values of the dimension

desc - The field descriptor for the field containing the reference.

Returns:

A data record with the given name and a navigation link.

extendGraph

public boolean extendGraph(java.lang.String graphName,
                  Graph<DataRecord,DataRecord> graph,
                  DataRecord node)

Extend the given graph around the specified node. If the graphName is empty or null, and there is only one graph defined, that graph will be used by default.

Specified by:

extendGraph in interface DataAccessor<DataRecord,DataRecord>

Overrides:

extendGraph in class RecordAccessor

Parameters:

graphName - The name of the graph

graph - The graph to extend

node - The node to use as an extension point.

Returns:

true if more data was added to the graph, false otherwise.

extendTree

public boolean extendTree(java.lang.String treeName,
                 Tree<DataRecord> tree,
                 DataRecord node)

Extend the given tree around the specified node. This method adds any children which are not already part of the tree. The default implementation simply returns false. SemanticAccessors which can extend the graph should override this method.

Specified by:

extendTree in interface DataAccessor<DataRecord,DataRecord>

Overrides:

extendTree in class RecordAccessor

Parameters:

treeName - The name of the graph

tree - The graph to extend

node - The node to use as an extension point.

Returns:

true if more data was added to the tree, false otherwise.

retrieveRecords

protected java.util.Set<DataRecord> retrieveRecords(DataTemplate template)

Retrieve a set of data records for a particular DataTemplate. This method is used by the various getStructure methods.

Specified by:

retrieveRecords in class RecordAccessor

Parameters:

template - The data template specifying field mappings and descriptions

Returns:

the set of DataRecords for the template

setInitParameters

public void setInitParameters(java.util.Map<java.lang.String,java.lang.String> parameters)

Set any initialization parameters required by this data accessor. The key for the only parameters are solrQueryUrl, which should contain the base URL for Solr queries, and the optional defaultQuery, which indicates the default query for the accessor. If it is not set, the query matching all records is used.

If this accessor has not been initialized with data templates and data structure specifications, this method will try to read the schema from the Solr instance, and create a default data set representation from the schema.

Parameters:

parameters - a map of initialization parameters

setQuery

public void setQuery(java.lang.String queryString)

Set the query string used to retrieve records. This method should transform the query string into a format which the accessor can parse. The query string supports a query of the form field=value.

Specified by:

setQuery in class AbstractDataAccessor<DataRecord,DataRecord>

Parameters:

queryString - the query string