/*
* Copyright 2008-2013 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.data.jpa.repository.query;
import java.lang.reflect.Method;
import javax.persistence.EntityManager;
import org.springframework.data.repository.core.NamedQueries;
import org.springframework.data.repository.core.RepositoryMetadata;
import org.springframework.data.repository.query.EvaluationContextProvider;
import org.springframework.data.repository.query.QueryLookupStrategy;
import org.springframework.data.repository.query.QueryLookupStrategy.Key;
import org.springframework.data.repository.query.RepositoryQuery;
import org.springframework.util.Assert;
/**
* Query lookup strategy to execute finders.
*
* @author Oliver Gierke
* @author Thomas Darimont
*/
public final class JpaQueryLookupStrategy {
/**
* Private constructor to prevent instantiation.
*/
private JpaQueryLookupStrategy() {}
/**
* Base class for {@link QueryLookupStrategy} implementations that need access to an {@link EntityManager}.
*
* @author Oliver Gierke
* @author Thomas Darimont
*/
private abstract static class AbstractQueryLookupStrategy implements QueryLookupStrategy {
private final EntityManager em;
private final QueryExtractor provider;
protected final EvaluationContextProvider evaluationContextProvider;
/**
* Creates a new {@link AbstractQueryLookupStrategy}.
*
* @param em
* @param extractor
* @param evaluationContextProvider
*/
public AbstractQueryLookupStrategy(EntityManager em, QueryExtractor extractor,
EvaluationContextProvider evaluationContextProvider) {
this.em = em;
this.provider = extractor;
this.evaluationContextProvider = evaluationContextProvider;
}
/*
* (non-Javadoc)
*
* @see org.springframework.data.repository.query.QueryLookupStrategy#
* resolveQuery(java.lang.reflect.Method,
* org.springframework.data.repository.core.RepositoryMetadata,
* org.springframework.data.repository.core.NamedQueries)
*/
public final RepositoryQuery resolveQuery(Method method, RepositoryMetadata metadata, NamedQueries namedQueries) {
return resolveQuery(new JpaQueryMethod(method, metadata, provider), em, namedQueries);
}
protected abstract RepositoryQuery resolveQuery(JpaQueryMethod method, EntityManager em, NamedQueries namedQueries);
}
/**
* {@link QueryLookupStrategy} to create a query from the method name.
*
* @author Oliver Gierke
* @author Thomas Darimont
*/
private static class CreateQueryLookupStrategy extends AbstractQueryLookupStrategy {
public CreateQueryLookupStrategy(EntityManager em, QueryExtractor extractor,
EvaluationContextProvider evaluationContextProvider) {
super(em, extractor, evaluationContextProvider);
}
@Override
protected RepositoryQuery resolveQuery(JpaQueryMethod method, EntityManager em, NamedQueries namedQueries) {
try {
return new PartTreeJpaQuery(method, em);
} catch (IllegalArgumentException e) {
throw new IllegalArgumentException(String.format("Could not create query metamodel for method %s!",
method.toString()), e);
}
}
}
/**
* {@link QueryLookupStrategy} that tries to detect a declared query declared via {@link Query} annotation followed by
* a JPA named query lookup.
*
* @author Oliver Gierke
* @author Thomas Darimont
*/
private static class DeclaredQueryLookupStrategy extends AbstractQueryLookupStrategy {
/**
* Creates a new {@link DeclaredQueryLookupStrategy}.
*
* @param em
* @param extractor
* @param evaluationContextProvider
*/
public DeclaredQueryLookupStrategy(EntityManager em, QueryExtractor extractor,
EvaluationContextProvider evaluationContextProvider) {
super(em, extractor, evaluationContextProvider);
}
@Override
protected RepositoryQuery resolveQuery(JpaQueryMethod method, EntityManager em, NamedQueries namedQueries) {
RepositoryQuery query = JpaQueryFactory.INSTANCE.fromQueryAnnotation(method, em, this.evaluationContextProvider);
if (null != query) {
return query;
}
query = JpaQueryFactory.INSTANCE.fromProcedureAnnotation(method, em);
if (null != query) {
return query;
}
String name = method.getNamedQueryName();
if (namedQueries.hasQuery(name)) {
return JpaQueryFactory.INSTANCE.fromMethodWithQueryString(method, em, namedQueries.getQuery(name),
this.evaluationContextProvider);
}
query = NamedQuery.lookupFrom(method, em);
if (null != query) {
return query;
}
throw new IllegalStateException(String.format(
"Did neither find a NamedQuery nor an annotated query for method %s!", method));
}
}
/**
* {@link QueryLookupStrategy} to try to detect a declared query first (
* {@link org.springframework.data.jpa.repository.Query}, JPA named query). In case none is found we fall back on
* query creation.
*
* @author Oliver Gierke
* @author Thomas Darimont
*/
private static class CreateIfNotFoundQueryLookupStrategy extends AbstractQueryLookupStrategy {
private final DeclaredQueryLookupStrategy lookupStrategy;
private final CreateQueryLookupStrategy createStrategy;
/**
* Creates a new {@link CreateIfNotFoundQueryLookupStrategy}.
*
* @param em
* @param extractor
* @param createStrategy
* @param lookupStrategy
* @param evaluationContextProvider
*/
public CreateIfNotFoundQueryLookupStrategy(EntityManager em, QueryExtractor extractor,
CreateQueryLookupStrategy createStrategy, DeclaredQueryLookupStrategy lookupStrategy,
EvaluationContextProvider evaluationContextProvider) {
super(em, extractor, evaluationContextProvider);
this.createStrategy = createStrategy;
this.lookupStrategy = lookupStrategy;
}
@Override
protected RepositoryQuery resolveQuery(JpaQueryMethod method, EntityManager em, NamedQueries namedQueries) {
try {
return lookupStrategy.resolveQuery(method, em, namedQueries);
} catch (IllegalStateException e) {
return createStrategy.resolveQuery(method, em, namedQueries);
}
}
}
/**
* Creates a {@link QueryLookupStrategy} for the given {@link EntityManager} and {@link Key}.
*
* @param em must not be {@literal null}.
* @param key may be {@literal null}.
* @param extractor must not be {@literal null}.
* @param evaluationContextProvider must not be {@literal null}.
* @return
*/
public static QueryLookupStrategy create(EntityManager em, Key key, QueryExtractor extractor,
EvaluationContextProvider evaluationContextProvider) {
Assert.notNull(em, "EntityManager must not be null!");
Assert.notNull(extractor, "QueryExtractor must not be null!");
Assert.notNull(evaluationContextProvider, "EvaluationContextProvider must not be null!");
switch (key != null ? key : Key.CREATE_IF_NOT_FOUND) {
case CREATE:
return new CreateQueryLookupStrategy(em, extractor, evaluationContextProvider);
case USE_DECLARED_QUERY:
return new DeclaredQueryLookupStrategy(em, extractor, evaluationContextProvider);
case CREATE_IF_NOT_FOUND:
return new CreateIfNotFoundQueryLookupStrategy(em, extractor, new CreateQueryLookupStrategy(em, extractor,
evaluationContextProvider), new DeclaredQueryLookupStrategy(em, extractor, evaluationContextProvider),
evaluationContextProvider);
default:
throw new IllegalArgumentException(String.format("Unsupported query lookup strategy %s!", key));
}
}
}