Package org.keycloak.models.sessions.infinispan.query

Class QueryHelper

java.lang.Object

org.keycloak.models.sessions.infinispan.query.QueryHelper

public final class QueryHelper
extends Object

Field Summary

Fields

Modifier and Type	Field	Description
static final Function<Object[],Map.Entry<String,Long>>	PROJECTION_TO_STRING_LONG_ENTRY	Converts a projection with two values into a Map.Entry of String and Long, where the key is the first projection, and the second is the second project.
static final Function<Object[],Long>	SINGLE_PROJECTION_TO_LONG	Converts a single projection results into a long value.
static final Function<Object[],String>	SINGLE_PROJECTION_TO_STRING	Converts a single projection value into a String.

Method Summary

Modifier and Type	Method	Description
static <T, R> Optional<R>	fetchSingle(org.infinispan.commons.api.query.Query<T> query, Function<T,R> mapping)	Fetches a single value from the query.
static <T, R> Stream<R>	streamAll(org.infinispan.commons.api.query.Query<T> query, int batchSize, Function<T,R> mapping)	Streams using batching over all results from the Query.
static <T, R> Collection<R>	toCollection(org.infinispan.commons.api.query.Query<T> query, Function<T,R> mapping)	Performs the Query and returns the results.

Methods inherited from class java.lang.Object

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

Field Details

SINGLE_PROJECTION_TO_LONG

public static final Function<Object[],Long> SINGLE_PROJECTION_TO_LONG

Converts a single projection results into a long value.

SINGLE_PROJECTION_TO_STRING

public static final Function<Object[],String> SINGLE_PROJECTION_TO_STRING

Converts a single projection value into a String.

PROJECTION_TO_STRING_LONG_ENTRY

public static final Function<Object[],Map.Entry<String,Long>> PROJECTION_TO_STRING_LONG_ENTRY

Converts a projection with two values into a Map.Entry of String and Long, where the key is the first projection, and the second is the second project.

Method Details

fetchSingle

public static <T,
R> Optional<R> fetchSingle(org.infinispan.commons.api.query.Query<T> query,
 Function<T,R> mapping)

Fetches a single value from the query.

This method changes the Query state to return just a single value.

Type Parameters:

T - The Query response type.

R - The Optional type.

Parameters:

query - The Query instance.

mapping - The Function that maps the query results (projection) into the result.

Returns:

An Optional with the Query results mapped.

streamAll

public static <T,
R> Stream<R> streamAll(org.infinispan.commons.api.query.Query<T> query,
 int batchSize,
 Function<T,R> mapping)

Streams using batching over all results from the Query.

If a large result set is expected, this method is recommended to avoid loading downloading a lot of data in a single request.

The results are fetched on demand.

Warning: This method changes ignores the start offset and the max results. It will return everything.

Type Parameters:

T - The Query response type.

R - The Stream type.

Parameters:

query - The Query instance.

batchSize - The number of results to fetch for each remote request.

mapping - The Function that maps the query results (projection) into the result.

Returns:

A Stream with the results.

toCollection

public static <T,
R> Collection<R> toCollection(org.infinispan.commons.api.query.Query<T> query,
 Function<T,R> mapping)

Performs the Query and returns the results.

This method is preferred to Query.list() since it does not have to compute an accurate hit count (affects Indexed query performance).

If a large dataset is expected, use streamAll(Query, int, Function).

Type Parameters:

T - The Query response type.

R - The Collection type.

Parameters:

query - The Query instance.

mapping - The Function that maps the query results (projection) into the result.

Returns:

A Collection with the results.