CODEWITHSUNDEEP
java-8java-stream
TX T
TX T

Reputation: 817

Java 8 retrieve Map's values into an array with stream and filter

Would someone help me with getting the array of the map values with stream and filtering?

public class TheMap extends HashMap<String, String> {
    public TheMap(String name, String title) {
        super.put("name", name);
        super.put("title", title);
    }

    public static void main(final String[] args) {
        Map<Long, Map<String, String>>map = new HashMap<>();            

        map.put(0L, null);
        map.put(1L, new TheMap("jane", "engineer"));
        map.put(2L, new TheMap("john", "engineer"));
        map.put(3L, new TheMap(null, "manager"));
        map.put(4L, new TheMap("who", null));
        map.put(5L, new TheMap(null, null));
    }
}

The result that I am looking for is an ArrayList<TheMap> with only these two entries:

TheMap("jane", "engineer")
TheMap("john", "engineer")

Basically, retrieve TheMap with none-null name and title.

Upvotes: 5

Views: 3791

Answers (2)

VHS
VHS

Reputation: 10184

If you need an arrayList of TheMap, try the following way:

ArrayList<TheMap> as = map.values()
   .stream()
   .filter(v -> v != null && v.get("name") != null && v.get("title") != null)
   .map(m -> (TheMap)m)
   .collect(Collectors.toCollection(ArrayList::new)));

Upvotes: 3

S&#233;bastien Temprado
S&#233;bastien Temprado

Reputation: 1463

List<Map<String, String>> list = 
        map.values().stream().filter(v -> 
                              v != null && 
                              !v.entrySet().isEmpty() &&
                              !v.containsValue(null)).
        collect(Collectors.toList());

Upvotes: 4

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