Convert Map<?, Map<?, ?> to List of Objects

Question

I have the following collection:

Map<String, Map<SomeEnum, Long>> map = ...

Here's sample data:

{"Foo": {
    SomeEnum.BAR1: 1,
    SomeEnum.BAR2: 2,
    SomeEnum.BAR3: 3
  },
 "two": {...}

Since I know all enums, I want to convert it to the list of POJO. The definition of the object is as below:

class SomeClass {
  String name;
  long bar1Value;
  long bar2Value;
  long bar3Value;
}

I have tried different solutions, like with mapping inside mapping:

map.entrySet().stream()
.map(e -> e.getValue().entrySet().stream().map(innerEntry -> {
  long bar1 = 0;
  long bar2 = 0;
  long bar3 = 0;

  if(innerEntry.getKey().equals(SomeEnum.BAR1)) bar1 = innerEntry.getValue();
  if(innerEntry.getKey().equals(SomeEnum.BAR2)) bar2 = innerEntry.getValue();
  if(innerEntry.getKey().equals(SomeEnum.BAR3)) bar3 = innerEntry.getValue();

  return new SomeClass(e.getKey(), bar1, bar2, bar3);
}).collect(toList()).collect(toList());

Unfortuantely, what I am getting is List<List<SomeClass>>.

Is there any other, more elegant, way to handle this?

Answer 1

Would this work for you?

It requires a constructor for the target class but simply gets the values and creates an instance. Then it collects them to a list.

        List<SomeClass> list = map.entrySet().stream()
                .map(e -> new SomeClass(e.getKey(),
                        e.getValue().get(SomeEnum.BAR1),
                        e.getValue().get(SomeEnum.BAR2),
                        e.getValue().get(SomeEnum.BAR3)))
                .collect(Collectors.toList());

Class with constructor

class SomeClass {
    String name;
    long bar1Value;
    long bar2Value;
    long bar3Value;

    public SomeClass(String name, long bar1Value, long bar2Value,
        long bar3Value) {
        this.name = name;
        this.bar1Value = bar1Value;
        this.bar2Value = bar2Value;
        this.bar3Value = bar3Value;
    }       
}