Java Map Merge mergeMapsIgnoreDuplicateKeys( Map first, Map second)

Description

Generic map merge logic

License

Apache License

Parameter

Parameter	Description
first	first map
second	second map
T1	key type
T2	value type

Return

'first' merged with the second

Declaration

public static <T1, T2> Map<T1, T2> mergeMapsIgnoreDuplicateKeys(
        Map<T1, T2> first, Map<T1, T2> second) 

Method Source Code

//package com.java2s;
/*//  w  w w.  j a  v a  2 s.  c om
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.Map;

public class Main {
    /**
     * Generic map merge logic
     * @param first first map
     * @param second second map
     * @param <T1> key type
     * @param <T2> value type
     * @return 'first' merged with the second
     */
    public static <T1, T2> Map<T1, T2> mergeMapsIgnoreDuplicateKeys(
            Map<T1, T2> first, Map<T1, T2> second) {
        for (Map.Entry<T1, T2> entry : second.entrySet()) {
            T1 key = entry.getKey();
            if (!first.containsKey(key)) {
                first.put(key, entry.getValue());
            }
        }
        return first;
    }
}

Related

1. mergeMaps(Map m1, Map m2)
2. mergeMaps(Map map1, Map map2)
3. mergeMaps(Map defaultMap, Map customMap)
4. mergeMaps(Map destination, Map source)
5. mergeMaps(Map map1, Map map2)
6. mergeMapWithAdd(Map target, Map source)
7. mergeNestableMap(Map original, Map additional)
8. mergeNsPrefixes(final Map prioritaryPrefixes, final Map additionalPrefixes)
9. mergeOptions(Map> ssio, Map> allOptions)