com.avanza.ymer.MongoQueryFactory.java Source code

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Here is the source code for com.avanza.ymer.MongoQueryFactory.java

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/*
 * Copyright 2015 Avanza Bank AB
 *
 * 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 com.avanza.ymer;

import java.beans.PropertyDescriptor;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Objects;

import org.springframework.beans.BeanUtils;
import org.springframework.data.mongodb.core.convert.MongoConverter;
import org.springframework.data.mongodb.core.mapping.BasicMongoPersistentEntity;
import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;

/**
 * Builds a mongo {@link Query} object from any object, but maybe preferably from a GigaSpace template :-)
 *
 * @author joasah Joakim Sahlstrm
 *
 */
class MongoQueryFactory {

    private final HashMap<Class<?>, List<PropertyDescriptor>> propertyDescriptors = new HashMap<Class<?>, List<PropertyDescriptor>>();
    private final MongoMappingContext mongoMappingContext;
    private final MongoConverter mongoConverter;

    /**
     * @param mongoConverter {@link MongoConverter} extracted from the mongo datasource used in gigaspaces
     */
    public MongoQueryFactory(MongoConverter mongoConverter) {
        this.mongoConverter = Objects.requireNonNull(mongoConverter);
        this.mongoMappingContext = (MongoMappingContext) mongoConverter.getMappingContext();
    }

    /**
     * @param template Template object
     * @return A Spring mongo {@link Query}
     */
    public Query createMongoQueryFromTemplate(Object template) {
        try {
            Criteria criteria = null;
            BasicMongoPersistentEntity<?> pe = mongoMappingContext.getPersistentEntity(template.getClass());
            for (PropertyDescriptor pd : getTemplatablePropertyDescriptors(template.getClass())) {
                Object objectValue = pd.getReadMethod().invoke(template);
                if (objectValue == null) {
                    continue; // null == accept any value
                }

                String fieldName = pe.getPersistentProperty(pd.getName()).getFieldName();
                Object mongoValue = mongoConverter.convertToMongoType(objectValue);
                criteria = addCriteria(criteria, fieldName, mongoValue);
            }

            return criteria != null ? new Query(criteria) : new Query();
        } catch (Exception e) {
            throw new CouldNotCreateMongoQueryException(e);
        }
    }

    private Criteria addCriteria(Criteria c, String fieldName, Object mongoValue) {
        if (c == null) {
            return Criteria.where(fieldName).is(mongoValue);
        } else {
            return c.and(fieldName).is(mongoValue);
        }
    }

    private List<PropertyDescriptor> getTemplatablePropertyDescriptors(Class<?> type) {
        if (!propertyDescriptors.containsKey(type)) {
            propertyDescriptors.put(type, findTemplatablePropertyDescriptors(type));
        }
        return propertyDescriptors.get(type);
    }

    private List<PropertyDescriptor> findTemplatablePropertyDescriptors(Class<?> type) {
        ArrayList<PropertyDescriptor> result = new ArrayList<PropertyDescriptor>();
        for (PropertyDescriptor pd : BeanUtils.getPropertyDescriptors(type)) {
            if (!isNotTemplatableMethod(pd)) {
                result.add(pd);
            }
        }
        return result;
    }

    private boolean isNotTemplatableMethod(PropertyDescriptor pd) {
        return pd.getReadMethod() == null || pd.getReadMethod().getDeclaringClass() == Object.class
                || pd.getWriteMethod() == null || pd.getName().equals("versionID");
    }

}