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javacollectionshashmapcomparison

Comparing two hashmaps for equal values and same key sets?

How can I best compare two HashMaps, if I want to find out if none of them contains different keys than the other, and if the values of that keys match each other.

Map<objA, objB> mapA = new HashMap<objA, objB>();
mapA.put("A", "1");
mapA.put("B", "2");

Map<objA, objB> mapB = new HashMap<objA, objB>();
mapB.put("D", "4");
mapB.put("A", "1");

When comparing A with B, it should fail due to different keys B and D.

How could I best compare non-sorted hashmaps?

Solution

  • Make an equals check on the keySet() of both HashMaps.

    NOTE:

    If your Map contains String keys then it is no problem, but if your Map contains objA type keys then you need to make sure that your class objA implements equals().