Java Map Merge merge(final Map> targetContext, final Map> newContext)

Description

Merge one context onto another by adding or replacing values.

License

Apache License

Parameter

Parameter	Description
targetContext	the target of the merge
newContext	context to merge

Declaration

public static Map<String, Map<String, String>> merge(final Map<String, Map<String, String>> targetContext,
        final Map<String, Map<String, String>> newContext) 

Method Source Code

//package com.java2s;
/**/*  w ww.j a  v a  2 s.c o m*/
 * Copyright (C) 2014 BigLoupe http://bigloupe.github.io/SoS-JobScheduler/
 *
 * 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.*;

public class Main {
    /**
     * Merge one context onto another by adding or replacing values.
     * @param targetContext the target of the merge
     *                @param newContext context to merge
     */
    public static Map<String, Map<String, String>> merge(final Map<String, Map<String, String>> targetContext,
            final Map<String, Map<String, String>> newContext) {

        final HashMap<String, Map<String, String>> result = deepCopy(targetContext);
        for (final Map.Entry<String, Map<String, String>> entry : newContext.entrySet()) {
            if (!targetContext.containsKey(entry.getKey())) {
                result.put(entry.getKey(), new HashMap<String, String>());
            } else {
                result.put(entry.getKey(), new HashMap<String, String>(targetContext.get(entry.getKey())));
            }
            result.get(entry.getKey()).putAll(entry.getValue());
        }
        return result;
    }

    private static HashMap<String, Map<String, String>> deepCopy(Map<String, Map<String, String>> context) {
        HashMap<String, Map<String, String>> map = new HashMap<String, Map<String, String>>();
        for (final Map.Entry<String, Map<String, String>> entry : context.entrySet()) {
            map.put(entry.getKey(), new HashMap<String, String>(entry.getValue()));
        }
        return map;
    }
}

Related

1. deepMerge(Map m1, Map m2)
2. deepMerge(Map original, Map newMap)
3. merge(final Map lhs, final Map rhs)
4. merge(final Map map1, final Map map2)
5. merge(final Map... maps)
6. merge(List> list)
7. merge(Map map1, Map map2)
8. merge(Map options, Map addition)
9. merge(Map into, Map with)