Issue with Guava MapDifference is not returning the diffrence but both maps

Question

    public static Map<String, MapDifference.ValueDifference<String>> mapCompare(HashMap<String, String> hm, HashMap<String,String> hm2){
    MapDifference<String, String> diff = Maps.difference(hm, hm2);

    Map<String, MapDifference.ValueDifference<String>> entriesDiffering = diff.entriesDiffering();

    System.out.println("difrence  is -->" +entriesDiffering);
    return entriesDiffering;
}

hm1(hashmap1 value)

1:abc 2:xyz 3:eedd 4:[]asdfasd

hm2

1:abc 2:xyz 3:eedd 4:[]asdfas2d

**Notice the hm2 4th key entry has a different value.

Actual OutPut

diffrence is -->{1=(abc 2:xyz 3:eedd 4:[]asdfasd, abc 2:xyz 3:eedd 4:[]asdfas2d)}

Note:- the First key is separated with = in first map, while second map first key is missing altogether) not sure reason. but this is not what i am trying to resolve.

Expected: (Only the difference)

4:[]asdfas2d

Answer 1

It works fine if inputs are proper maps with 4 entries, as shown here (I use Splitter#withKeyValueSeparator to parse string to map:

@Test
public void properlyParsedMaps() {
    Map<String, String> map1 = MAP_SPLITTER.split("1:abc 2:xyz 3:eedd 4:[]asdfasd");  // {1=abc, 2=xyz, 3=eedd, 4=[]asdfasd}
    Map<String, String> map2 = MAP_SPLITTER.split("1:abc 2:xyz 3:eedd 4:[]asdfas2d"); // {1=abc, 2=xyz, 3=eedd, 4=[]asdfas2d}
    mapCompare(map1, map2); // signature slightly changed to accept any `Map`, not just `HashMap`
    // difrence  is -->{4=([]asdfasd, []asdfas2d)}
}

On the other hand in your example it seems you have maps with one key "1" and value which is the rest of the string (so probably not parsed as you expected):

@Test
public void reverseEngineeredMapsFromOutput() {
    Map<String, String> map1 = ImmutableMap.of("1", "abc 2:xyz 3:eedd 4:[]asdfasd");  // {1=abc 2:xyz 3:eedd 4:[]asdfasd}
    Map<String, String> map2 = ImmutableMap.of("1", "abc 2:xyz 3:eedd 4:[]asdfas2d"); // {1=abc 2:xyz 3:eedd 4:[]asdfas2d}
    mapCompare(map1, map2);
    // difrence  is -->{1=(abc 2:xyz 3:eedd 4:[]asdfasd, abc 2:xyz 3:eedd 4:[]asdfas2d)}
}

Please make sure you input arguments contain what you expect.