Java AtomicInteger deleteIndexedFields(Set<String> fieldsToDelete, List<String> fields, Map<String, AtomicInteger> fieldIndexLookupMap)

Description

Given a list of Strings and a map holding the index of each string, this method removes the strings and re-builds the index.

License

Apache License

Parameter

Parameter	Description
fieldsToDelete	the fields to delete
fields	the current fields to process
fieldIndexLookupMap	the current index of each field in the fields list

Return

the index of the removed field IF there is only ONE field to delete, otherwise -1.

Declaration

static int deleteIndexedFields(Set<String> fieldsToDelete, List<String> fields,
        Map<String, AtomicInteger> fieldIndexLookupMap)

Method Source Code

//package com.java2s;
/*/*from   w  w  w .j  a va 2 s. c  o m*/
 * Copyright (c) 2015 Ramon Servadei 
 *  
 * 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.
 */

import java.util.ArrayList;

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

import java.util.concurrent.atomic.AtomicInteger;

public class Main {
    /**
     * Given a list of Strings and a map holding the index of each string, this method removes the
     * strings and re-builds the index.
     * 
     * @param fieldsToDelete
     *            the fields to delete
     * @param fields
     *            the current fields to process
     * @param fieldIndexLookupMap
     *            the current index of each field in the fields list
     * @return the index of the removed field IF there is only ONE field to delete, otherwise -1.
     */
    static int deleteIndexedFields(Set<String> fieldsToDelete, List<String> fields,
            Map<String, AtomicInteger> fieldIndexLookupMap) {
        List<String> copy = new ArrayList<String>(fields);
        fields.clear();

        int singleIndex = -1;
        if (fieldsToDelete.size() == 1) {
            final AtomicInteger index = fieldIndexLookupMap.get(fieldsToDelete.iterator().next());
            if (index != null) {
                singleIndex = index.intValue();
            }
        }

        // first rebuild fieldIndex without the deleted fields
        final int size = copy.size();
        String fieldName;
        int i;
        for (i = 0; i < size; i++) {
            fieldName = copy.get(i);
            if (!fieldsToDelete.remove(fieldName)) {
                fields.add(fieldName);
            }
        }

        // rebuild indexes
        fieldIndexLookupMap.clear();
        for (i = 0; i < fields.size(); i++) {
            fieldIndexLookupMap.put(fields.get(i), new AtomicInteger(i));
        }

        return singleIndex;
    }
}

Java AtomicInteger deleteIndexedFields(Set fieldsToDelete, List fields, Map fieldIndexLookupMap)