com.ibm.amc.data.filter.QueryFilterEngine.java Source code

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Here is the source code for com.ibm.amc.data.filter.QueryFilterEngine.java

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/**
 * Copyright 2014 IBM Corp.
 *
 * 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.ibm.amc.data.filter;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;

import com.ibm.amc.Constants;
import com.ibm.amc.data.filter.QueryFilter.Operator;
import com.ibm.amc.ras.Logger47;

/**
 * Perform filtering action.
 * 
 * @author mallman
 */
public class QueryFilterEngine {
    // @CLASS-COPYRIGHT@

    static Logger47 logger = Logger47.get(QueryFilterEngine.class.getCanonicalName(), Constants.CWZBA_BUNDLE_NAME);

    @SuppressWarnings("unchecked")
    public static <T> List<T> filter(List<T> objects, Set<Map.Entry<String, List<String>>> queryParams) {
        if (logger.isEntryEnabled())
            logger.entry("filter", objects, queryParams);

        /* use a HashSet to remove duplicates */
        HashSet<T> filteredObjects = new HashSet<T>();

        QueryFilter filter = QueryFilterFactory.build(queryParams);

        if (filter.getOperator().equals(Operator.AND)) {
            if (logger.isDebugEnabled())
                logger.debug("filter", "Filter operator: AND");
            for (Predicate predicate : filter.getClauses()) {
                CollectionUtils.filter(objects, predicate);
            }

            /* need to muck about to get compatible types */
            ArrayList<T> temp;
            if (objects instanceof ArrayList) {
                temp = (ArrayList<T>) objects;
            } else {
                temp = new ArrayList<T>(objects);
            }

            filteredObjects.addAll(temp);
        } else {
            if (logger.isDebugEnabled())
                logger.debug("filter", "Filter operator: OR");
            for (Predicate predicate : filter.getClauses()) {
                filteredObjects.addAll(CollectionUtils.select(objects, predicate));
            }
        }

        if (logger.isEntryEnabled())
            logger.exit("filter", filteredObjects);
        return new ArrayList<T>(filteredObjects);
    }
}