/*
* Copyright 2014-2017 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.keyvalue.repository.query;
import java.lang.reflect.Constructor;
import org.springframework.beans.BeanUtils;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.keyvalue.core.IterableConverter;
import org.springframework.data.keyvalue.core.KeyValueOperations;
import org.springframework.data.keyvalue.core.SpelCriteria;
import org.springframework.data.keyvalue.core.query.KeyValueQuery;
import org.springframework.data.repository.query.EvaluationContextProvider;
import org.springframework.data.repository.query.ParameterAccessor;
import org.springframework.data.repository.query.ParametersParameterAccessor;
import org.springframework.data.repository.query.QueryMethod;
import org.springframework.data.repository.query.RepositoryQuery;
import org.springframework.data.repository.query.ResultProcessor;
import org.springframework.data.repository.query.parser.AbstractQueryCreator;
import org.springframework.data.repository.query.parser.PartTree;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.spel.standard.SpelExpression;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* {@link RepositoryQuery} implementation deriving queries from {@link PartTree} using a predefined
* {@link AbstractQueryCreator}.
*
* @author Christoph Strobl
* @author Oliver Gierke
* @author Mark Paluch
*/
public class KeyValuePartTreeQuery implements RepositoryQuery {
private final EvaluationContextProvider evaluationContextProvider;
private final QueryMethod queryMethod;
private final KeyValueOperations keyValueOperations;
private final Class<? extends AbstractQueryCreator<?, ?>> queryCreator;
/**
* Creates a new {@link KeyValuePartTreeQuery} for the given {@link QueryMethod}, {@link EvaluationContextProvider},
* {@link KeyValueOperations} and query creator type.
*
* @param queryMethod must not be {@literal null}.
* @param evaluationContextProvider must not be {@literal null}.
* @param keyValueOperations must not be {@literal null}.
* @param queryCreator must not be {@literal null}.
*/
public KeyValuePartTreeQuery(QueryMethod queryMethod, EvaluationContextProvider evaluationContextProvider,
KeyValueOperations keyValueOperations, Class<? extends AbstractQueryCreator<?, ?>> queryCreator) {
Assert.notNull(queryMethod, "Query method must not be null!");
Assert.notNull(evaluationContextProvider, "EvaluationContextprovider must not be null!");
Assert.notNull(keyValueOperations, "KeyValueOperations must not be null!");
Assert.notNull(queryCreator, "QueryCreator type must not be null!");
this.queryMethod = queryMethod;
this.keyValueOperations = keyValueOperations;
this.evaluationContextProvider = evaluationContextProvider;
this.queryCreator = queryCreator;
}
/*
* (non-Javadoc)
* @see org.springframework.data.repository.query.RepositoryQuery#execute(java.lang.Object[])
*/
@Override
public Object execute(Object[] parameters) {
ParameterAccessor accessor = new ParametersParameterAccessor(getQueryMethod().getParameters(), parameters);
KeyValueQuery<?> query = prepareQuery(parameters);
ResultProcessor processor = queryMethod.getResultProcessor().withDynamicProjection(accessor);
return processor.processResult(doExecute(parameters, query));
}
/**
* @param parameters
* @param query
*/
@SuppressWarnings({ "unchecked", "rawtypes" })
protected Object doExecute(Object[] parameters, KeyValueQuery<?> query) {
if (queryMethod.isPageQuery() || queryMethod.isSliceQuery()) {
Pageable page = (Pageable) parameters[queryMethod.getParameters().getPageableIndex()];
query.setOffset(page.getOffset());
query.setRows(page.getPageSize());
Iterable<?> result = this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
long count = queryMethod.isSliceQuery() ? 0
: keyValueOperations.count(query, queryMethod.getEntityInformation().getJavaType());
return new PageImpl(IterableConverter.toList(result), page, count);
} else if (queryMethod.isCollectionQuery()) {
return this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
} else if (queryMethod.isQueryForEntity()) {
Iterable<?> result = this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
return result.iterator().hasNext() ? result.iterator().next() : null;
}
throw new UnsupportedOperationException("Query method not supported.");
}
protected KeyValueQuery<?> prepareQuery(Object[] parameters) {
return prepareQuery(createQuery(new ParametersParameterAccessor(getQueryMethod().getParameters(), parameters)),
parameters);
}
@SuppressWarnings({ "rawtypes", "unchecked" })
protected KeyValueQuery<?> prepareQuery(KeyValueQuery<?> instance, Object[] parameters) {
ParametersParameterAccessor accessor = new ParametersParameterAccessor(getQueryMethod().getParameters(),
parameters);
Object criteria = instance.getCriteria();
if (criteria instanceof SpelCriteria || criteria instanceof SpelExpression) {
SpelExpression spelExpression = getSpelExpression(criteria);
EvaluationContext context = this.evaluationContextProvider.getEvaluationContext(getQueryMethod().getParameters(),
parameters);
criteria = new SpelCriteria(spelExpression, context);
}
KeyValueQuery<?> query = new KeyValueQuery(criteria);
Pageable pageable = accessor.getPageable();
Sort sort = accessor.getSort();
query.setOffset(pageable.toOptional().map(Pageable::getOffset).orElse(-1L));
if (pageable.isPaged()) {
query.setRows(pageable.getPageSize());
} else if (instance.getRows() >= 0) {
query.setRows(instance.getRows());
}
query.setSort(sort == null || sort.isUnsorted() ? instance.getSort() : sort);
return query;
}
private SpelExpression getSpelExpression(Object criteria) {
if (criteria instanceof SpelExpression) {
return (SpelExpression) criteria;
}
if (criteria instanceof SpelCriteria) {
return getSpelExpression(((SpelCriteria) criteria).getExpression());
}
throw new IllegalStateException(String.format("Cannot retrieve SpelExpression from %s", criteria));
}
public KeyValueQuery<?> createQuery(ParameterAccessor accessor) {
PartTree tree = new PartTree(getQueryMethod().getName(), getQueryMethod().getEntityInformation().getJavaType());
Constructor<? extends AbstractQueryCreator<?, ?>> constructor = ClassUtils
.getConstructorIfAvailable(queryCreator, PartTree.class, ParameterAccessor.class);
KeyValueQuery<?> query = (KeyValueQuery<?>) BeanUtils.instantiateClass(constructor, tree, accessor).createQuery();
if (tree.isLimiting()) {
query.setRows(tree.getMaxResults());
}
return query;
}
/*
* (non-Javadoc)
* @see org.springframework.data.repository.query.RepositoryQuery#getQueryMethod()
*/
@Override
public QueryMethod getQueryMethod() {
return queryMethod;
}
}