Package com.epimorphics.rdfutil

Class QueryUtil

java.lang.Object

com.epimorphics.rdfutil.QueryUtil

public class QueryUtil
extends Object

Random small utilities to help with SPARQl queries.

Constructor Summary

Constructors

Constructor	Description
QueryUtil()

Method Summary

Modifier and Type	Method	Description
static String	addPageLimits(String query, PageInfo pageInfo)	Add limit/offset to query based on paging specification.
static String	asSPARQLValue(Object val)	Format a value in a way that we can include it in a SPARQL query string
static List<org.apache.jena.rdf.model.Literal>	connectedLiterals(org.apache.jena.rdf.model.Resource root, String path)	Return all Literals connected by a property path to the given resource.
static List<org.apache.jena.rdf.model.Resource>	connectedResources(org.apache.jena.rdf.model.Resource root, String path)	Return all resources connected by a property path to the given resource.
static org.apache.jena.query.QuerySolutionMap	createBindings(Object... bindings)	Utility to declare bindings in code.
static org.apache.jena.query.QueryExecution	createQueryExecution(org.apache.jena.rdf.model.Model m, String query)	Create a QueryExecution for executing the given query against the given model.
static org.apache.jena.query.QueryExecution	createQueryExecution(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Create a QueryExecution for executing the given query against the given model.
static org.apache.jena.query.QueryExecution	createQueryExecution(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, org.apache.jena.query.QuerySolutionMap bindings)	Create a QueryExecution for executing the given query against the given model.
static org.apache.jena.rdf.model.Model	describe(org.apache.jena.rdf.model.Model m, String query)	Return the model that results from executing the given describe query.
static org.apache.jena.rdf.model.Model	describe(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return the model that results from executing the given describe query.
static org.apache.jena.rdf.model.Model	describe(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, org.apache.jena.query.QuerySolutionMap bindings)	Return the model that results from executing the given describe query.
static org.apache.jena.rdf.model.Model	describeResource(org.apache.jena.rdf.model.Model m, String uri)	Return the model that is the SPARQL description of resource with the given URI
static org.apache.jena.rdf.model.Model	describeResource(org.apache.jena.rdf.model.Model m, org.apache.jena.rdf.model.Resource r)	Return the model that is the SPARQL description of resource r
protected static List<org.apache.jena.rdf.model.RDFNode>	getResultSetAll(String var, org.apache.jena.query.ResultSet rs)
protected static org.apache.jena.rdf.model.RDFNode	getResultSetFirst(String var, org.apache.jena.query.QueryExecution qe, org.apache.jena.query.ResultSet rs)
static List<org.apache.jena.rdf.model.Resource>	resultsFor(org.apache.jena.query.ResultSet results, String varname)	Take a column from result set and extract it as a list of resources.
static <T> List<T>	resultsFor(org.apache.jena.query.ResultSet results, String varname, Class<T> cls)	Take a column from result set and extract it as a list of values of the given type (e.g.
static org.apache.jena.query.ResultSet	selectAll(org.apache.jena.rdf.model.Model m, String query)	Return all results from executing the given select query.
static org.apache.jena.query.ResultSet	selectAll(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return all results from executing the given select query.
static org.apache.jena.query.ResultSet	selectAll(org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, org.apache.jena.query.QuerySolutionMap bindings)	Return all results from executing the given select query.
static List<org.apache.jena.rdf.model.RDFNode>	selectAllVar(String var, org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return all results from executing the given select query for a given variable.
static org.apache.jena.rdf.model.RDFNode	selectFirstVar(String var, org.apache.jena.rdf.model.Model m, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return the first result from executing the given select query, for a given variable.
static org.apache.jena.rdf.model.Model	serviceDescribe(String serviceURL, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Execute a describe query against a remote SPARQL endpoint.
static org.apache.jena.query.ResultSet	serviceSelectAll(String serviceURL, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Execute a select query against a remote SPARQL endpoint.
static org.apache.jena.query.ResultSet	serviceSelectAll(String serviceURL, String query, org.apache.jena.shared.PrefixMapping pm, org.apache.jena.query.QuerySolutionMap bindings)	Execute a select query against a remote SPARQL endpoint.
static List<org.apache.jena.rdf.model.RDFNode>	serviceSelectAllVar(String var, String serviceURL, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return all values for the given var from executing the given query against the given remote sparql endpoint.
static org.apache.jena.rdf.model.RDFNode	serviceSelectFirstVar(String var, String serviceURL, String query, org.apache.jena.shared.PrefixMapping pm, Object... bindings)	Return the first value for the given var from executing the given query against the given remote sparql endpoint.
static String	substituteInQuery(String query, Object... strings)	Inject strings into a SPARQL query replacing each ${i} with the corresponding element from the arg list.
static String	substituteVars(String query, org.apache.jena.query.QuerySolutionMap bindings)	Substitute the variables in a query string for the values from the given binding.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryUtil

public QueryUtil()

Method Detail

substituteInQuery

public static String substituteInQuery(String query,
                                       Object... strings)

Inject strings into a SPARQL query replacing each ${i} with the corresponding element from the arg list. Purely syntactic. Up to the caller to protected any sensitive characters.

addPageLimits

public static String addPageLimits(String query,
                                   PageInfo pageInfo)

Add limit/offset to query based on paging specification.

resultsFor

public static List<org.apache.jena.rdf.model.Resource> resultsFor(org.apache.jena.query.ResultSet results,
                                                                  String varname)

Take a column from result set and extract it as a list of resources. Skips any non-resource results.

createBindings

public static org.apache.jena.query.QuerySolutionMap createBindings(Object... bindings)

Utility to declare bindings in code. Called with an array of objects, each pairs of sequential objecst will be interpreted as string denoting a variable name, and a value denoting an RDFNode via RDFUtil.asRDFNode(Object).

Parameters:

bindings - An array of Objects, which will be taken in pairs to be a string var name and an object to encode as an RDF node.

Returns:

A QuerySolutionMap in which the keys are bound to their given values

createQueryExecution

public static org.apache.jena.query.QueryExecution createQueryExecution(org.apache.jena.rdf.model.Model m,
                                                                        String query)

Create a QueryExecution for executing the given query against the given model. Other variants allow prefix mappings and initial variable bindings to be specified. Uses the default common prefixes.

Parameters:

m - The model to run queries against

query - The query to run

Returns:

A query execution object

createQueryExecution

public static org.apache.jena.query.QueryExecution createQueryExecution(org.apache.jena.rdf.model.Model m,
                                                                        String query,
                                                                        org.apache.jena.shared.PrefixMapping pm,
                                                                        Object... bindings)

Create a QueryExecution for executing the given query against the given model. This variant allows additional prefixes for the query to be passed in, together with bindings for variables.

Parameters:

m - The model to run queries against

query - The query to run

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional array of name/value pairs to use as initial variable bindings

Returns:

A query execution object

createQueryExecution

public static org.apache.jena.query.QueryExecution createQueryExecution(org.apache.jena.rdf.model.Model m,
                                                                        String query,
                                                                        org.apache.jena.shared.PrefixMapping pm,
                                                                        org.apache.jena.query.QuerySolutionMap bindings)

Create a QueryExecution for executing the given query against the given model. This variant allows additional prefixes for the query to be passed in, together with bindings for variables.

Parameters:

m - The model to run queries against

query - The query to run

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional QuerySolutionMap containing initial bindings for query variables

Returns:

A query execution object

selectAll

public static org.apache.jena.query.ResultSet selectAll(org.apache.jena.rdf.model.Model m,
                                                        String query)

Return all results from executing the given select query. Uses the default commont prefixes.

Parameters:

m - The model to run the query against

query - The sparql query

Returns:

ResultSet of all values

selectAll

public static org.apache.jena.query.ResultSet selectAll(org.apache.jena.rdf.model.Model m,
                                                        String query,
                                                        org.apache.jena.shared.PrefixMapping pm,
                                                        Object... bindings)

Return all results from executing the given select query.

Parameters:

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional array of name/value pairs to use as initial variable bindings

Returns:

ResultSet of all values

selectAll

public static org.apache.jena.query.ResultSet selectAll(org.apache.jena.rdf.model.Model m,
                                                        String query,
                                                        org.apache.jena.shared.PrefixMapping pm,
                                                        org.apache.jena.query.QuerySolutionMap bindings)

Return all results from executing the given select query.

Parameters:

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional QuerySolutionMap containing initial bindings for query variables

Returns:

ResultSet of all values

selectAllVar

public static List<org.apache.jena.rdf.model.RDFNode> selectAllVar(String var,
                                                                   org.apache.jena.rdf.model.Model m,
                                                                   String query,
                                                                   org.apache.jena.shared.PrefixMapping pm,
                                                                   Object... bindings)

Return all results from executing the given select query for a given variable.

Parameters:

var - The variable name to project from the query results

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional QuerySolutionMap containing initial bindings for query variables

Returns:

Non-null list of the values for var

selectFirstVar

public static org.apache.jena.rdf.model.RDFNode selectFirstVar(String var,
                                                               org.apache.jena.rdf.model.Model m,
                                                               String query,
                                                               org.apache.jena.shared.PrefixMapping pm,
                                                               Object... bindings)

Return the first result from executing the given select query, for a given variable.

Parameters:

var - The variable name to project from the query results

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional QuerySolutionMap containing initial bindings for query variables

Returns:

The first value for var, or null

describeResource

public static org.apache.jena.rdf.model.Model describeResource(org.apache.jena.rdf.model.Model m,
                                                               org.apache.jena.rdf.model.Resource r)

Return the model that is the SPARQL description of resource r

Parameters:

m -

r -

Returns:

describeResource

public static org.apache.jena.rdf.model.Model describeResource(org.apache.jena.rdf.model.Model m,
                                                               String uri)

Return the model that is the SPARQL description of resource with the given URI

Parameters:

m -

uri -

Returns:

describe

public static org.apache.jena.rdf.model.Model describe(org.apache.jena.rdf.model.Model m,
                                                       String query)

Return the model that results from executing the given describe query. Uses the default common prefixes.

Parameters:

m - The model to run the query against

query - The sparql query

Returns:

ResultSet of all values

describe

public static org.apache.jena.rdf.model.Model describe(org.apache.jena.rdf.model.Model m,
                                                       String query,
                                                       org.apache.jena.shared.PrefixMapping pm,
                                                       Object... bindings)

Return the model that results from executing the given describe query.

Parameters:

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null. If null is given, the default prefixes from PrefixUtils.commonPrefixes() will be used

bindings - Optional array of name/value pairs to use as initial variable bindings

Returns:

ResultSet of all values

describe

public static org.apache.jena.rdf.model.Model describe(org.apache.jena.rdf.model.Model m,
                                                       String query,
                                                       org.apache.jena.shared.PrefixMapping pm,
                                                       org.apache.jena.query.QuerySolutionMap bindings)

Return the model that results from executing the given describe query.

Parameters:

m - The model to run the query against

query - The sparql query

pm - Optional PrefixMapping to use when parsing the query, or null.

bindings - Optional QuerySolutionMap containing initial bindings for query variables

Returns:

ResultSet of all values

asSPARQLValue

public static String asSPARQLValue(Object val)

Format a value in a way that we can include it in a SPARQL query string

Parameters:

val -

Returns:

The value formatted for SPARQL

substituteVars

public static String substituteVars(String query,
                                    org.apache.jena.query.QuerySolutionMap bindings)

Substitute the variables in a query string for the values from the given binding. This produces a new query string, suitable, for example, for sending to a remote service endpoint.

Parameters:

query - The query string to act on

bindings - A set of value bindings for variables that may occur in query

serviceSelectAll

public static org.apache.jena.query.ResultSet serviceSelectAll(String serviceURL,
                                                               String query,
                                                               org.apache.jena.shared.PrefixMapping pm,
                                                               Object... bindings)

Execute a select query against a remote SPARQL endpoint.

Parameters:

serviceURL - The address of the SPARQL endpoint, as a string

query - The query string to send

pm - Optional prefix map. If null, the default common prefixes will be used

bindings - Optional bindings for variables in the query string, in pairs of variable name and value

Returns:

The resultset of all results

serviceSelectAll

public static org.apache.jena.query.ResultSet serviceSelectAll(String serviceURL,
                                                               String query,
                                                               org.apache.jena.shared.PrefixMapping pm,
                                                               org.apache.jena.query.QuerySolutionMap bindings)

Execute a select query against a remote SPARQL endpoint.

Parameters:

serviceURL - The address of the SPARQL endpoint, as a string

query - The query string to send

pm - Optional prefix map. If null, the default common prefixes will be used

bindings - Optional bindings for variables in the query string, in pairs of variable name and value

Returns:

The resultset of all results

serviceSelectAllVar

public static List<org.apache.jena.rdf.model.RDFNode> serviceSelectAllVar(String var,
                                                                          String serviceURL,
                                                                          String query,
                                                                          org.apache.jena.shared.PrefixMapping pm,
                                                                          Object... bindings)

Return all values for the given var from executing the given query against the given remote sparql endpoint.

Parameters:

var -

serviceURL -

query -

pm -

bindings -

Returns:

serviceSelectFirstVar

public static org.apache.jena.rdf.model.RDFNode serviceSelectFirstVar(String var,
                                                                      String serviceURL,
                                                                      String query,
                                                                      org.apache.jena.shared.PrefixMapping pm,
                                                                      Object... bindings)

Return the first value for the given var from executing the given query against the given remote sparql endpoint.

Parameters:

var -

serviceURL -

query -

pm -

bindings -

Returns:

serviceDescribe

public static org.apache.jena.rdf.model.Model serviceDescribe(String serviceURL,
                                                              String query,
                                                              org.apache.jena.shared.PrefixMapping pm,
                                                              Object... bindings)

Execute a describe query against a remote SPARQL endpoint.

Parameters:

serviceURL - The address of the SPARQL endpoint, as a string

query - The query string to send

pm - Optional prefix map. If null, the default common prefixes will be used

bindings - Optional bindings for variables in the query string, in pairs of variable name and value

Returns:

The resultset of all results

connectedResources

public static List<org.apache.jena.rdf.model.Resource> connectedResources(org.apache.jena.rdf.model.Resource root,
                                                                          String path)

Return all resources connected by a property path to the given resource. Path can use prefixes defined in the resource's Model.

connectedLiterals

public static List<org.apache.jena.rdf.model.Literal> connectedLiterals(org.apache.jena.rdf.model.Resource root,
                                                                        String path)

Return all Literals connected by a property path to the given resource. Path can use prefixes defined in the resource's Model.

getResultSetFirst

protected static org.apache.jena.rdf.model.RDFNode getResultSetFirst(String var,
                                                                     org.apache.jena.query.QueryExecution qe,
                                                                     org.apache.jena.query.ResultSet rs)

Parameters:

var -

qe -

rs -

Returns:

getResultSetAll

protected static List<org.apache.jena.rdf.model.RDFNode> getResultSetAll(String var,
                                                                         org.apache.jena.query.ResultSet rs)

Parameters:

var -

rs -

Returns:

resultsFor

public static <T> List<T> resultsFor(org.apache.jena.query.ResultSet results,
                                     String varname,
                                     Class<T> cls)

Take a column from result set and extract it as a list of values of the given type (e.g. Resource, Literal or generic RDFNode. Skips any non-matching results

Type Parameters:

T -