Package org.springframework.data.repository.query

Class SpelQueryContext

java.lang.Object

org.springframework.data.repository.query.SpelQueryContext

Direct Known Subclasses:

SpelQueryContext.EvaluatingSpelQueryContext

public class SpelQueryContext
extends Object

A SpelQueryContext is able to find SpEL expressions in a query string and to replace them with bind variables.

Result o the parse process is a SpelQueryContext.SpelExtractor which offers the transformed query string. Alternatively and preferred one may provide a QueryMethodEvaluationContextProvider via withEvaluationContextProvider(QueryMethodEvaluationContextProvider) which will yield the more powerful SpelQueryContext.EvaluatingSpelQueryContext.

Typical usage looks like

 
     SpelQueryContext.EvaluatingSpelQueryContext queryContext = SpelQueryContext
         .of((counter, expression) -> String.format("__$synthetic$__%d", counter), String::concat)
         .withEvaluationContextProvider(evaluationContextProvider);

     SpelEvaluator spelEvaluator = queryContext.parse(query, queryMethod.getParameters());

     spelEvaluator.evaluate(objects).forEach(parameterMap::addValue);
 
 

Since:

2.1

Author:

Jens Schauder, Gerrit Meier, Mark Paluch

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SpelQueryContext.EvaluatingSpelQueryContext	An extension of SpelQueryContext that can create SpelEvaluator instances as it also knows about a QueryMethodEvaluationContextProvider.
class	SpelQueryContext.SpelExtractor	Parses a query string, identifies the contained SpEL expressions, replaces them with bind parameters and offers a Map from those bind parameters to the SpEL expression.

Method Summary

Modifier and Type	Method	Description
static SpelQueryContext	of(BiFunction<Integer,String,String> parameterNameSource, BiFunction<String,String,String> replacementSource)
SpelQueryContext.SpelExtractor	parse(String query)	Parses the query for SpEL expressions using the pattern:
SpelQueryContext.EvaluatingSpelQueryContext	withEvaluationContextProvider(QueryMethodEvaluationContextProvider provider)	Createsa SpelQueryContext.EvaluatingSpelQueryContext from the current one and the given QueryMethodEvaluationContextProvider.

Methods inherited from class java.lang.Object

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

Method Details

of

public static SpelQueryContext of(BiFunction<Integer,String,String> parameterNameSource,
 BiFunction<String,String,String> replacementSource)

parse

public SpelQueryContext.SpelExtractor parse(String query)

Parses the query for SpEL expressions using the pattern:

 <prefix>#{<spel>}
 

with prefix being the character ':' or '?'. Parsing honors quoted Strings enclosed in single or double quotation marks.

Parameters:

query - a query containing SpEL expressions in the format described above. Must not be null.

Returns:

A SpelQueryContext.SpelExtractor which makes the query with SpEL expressions replaced by bind parameters and a map from bind parameter to SpEL expression available. Guaranteed to be not null.

withEvaluationContextProvider

public SpelQueryContext.EvaluatingSpelQueryContext withEvaluationContextProvider(QueryMethodEvaluationContextProvider provider)

Createsa SpelQueryContext.EvaluatingSpelQueryContext from the current one and the given QueryMethodEvaluationContextProvider.

Parameters:

provider - must not be null.

Returns: