Java Map Copy copyHashMap(HashMap map1, HashMap map2)

Description

this works only for hashmaps having similar keysets or copying into new hashmap

License

Open Source License

Parameter

Parameter	Description
map1	a parameter
map2	a parameter
K	a parameter
V	a parameter

Declaration

public static <K, V> void copyHashMap(HashMap<K, V> map1, HashMap<K, V> map2) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

import java.util.*;

public class Main {
    /**/*from   w ww. j  av a2 s.c  om*/
     * this works only for hashmaps having similar keysets
     * or
     * copying into new hashmap
     * @param map1
     * @param map2
     * @param <K>
     * @param <V>
     */
    public static <K, V> void copyHashMap(HashMap<K, V> map1, HashMap<K, V> map2) {
        Set<K> keySet1 = map1.keySet();
        Set<K> keySet2 = map2.keySet();

        Iterator<K> iter1 = keySet1.iterator();

        if (map2.size() == 0) {
            while (iter1.hasNext()) {
                K item1 = iter1.next();
                map2.put(item1, map1.get(item1));
            }
        }

        else {
            while (iter1.hasNext()) {
                K item1 = iter1.next();
                Iterator<K> iter2 = keySet2.iterator();
                while (iter2.hasNext()) {
                    K item2 = iter2.next();
                    if (item2.equals(item1)) {
                        map1.put(item1, map2.get(item1)); // copies values of map2 into map1
                        break;
                    }
                }

            }
        }

    }
}

Related

1. copy(Map src, Map dst)
2. copyAndRemove(Map map, K key)
3. copyDeep(Map> data)
4. copyEntries(Map aSource, Map aTarget)
5. copyExcludingKeys(Map map, Set excludedKeys)
6. copyLowerCaseMap(Map map)
7. copyMap(Map from, Map to)
8. copyMap(Map sourceMap, Map targetMap)
9. copyMap(Map m)