Java 8 stream filters the values in the list

I have an object that looks like this

class MyObject {

    String type;
    List<String> subTypes;

}

Is it possible to use Java 8 streams to filter types and subtypes given a MyObject list?

So far I have

myObjects.stream()
    .filter(t -> t.getType().equals(someotherType)
    .collect(Collections.toList());

But in this scope, I also want to use another filter on each subtype to filter the subtypes of a particular subtype I can't figure out how to do this

One example is

myObject { type: A,subTypes [ { X,Y,Z } ] }
myObject { type: B,subTypes [ { W,X,Y } ] }
myObject { type: B,Z } ] }
myObject { type: C,Z } ] }

I will pass in matchtype B and subtype Z, so I want to get a result – > MyObject type B, subtype: W, Z

The following content currently returns 2 items in the list

myObjects.stream()
    .filter(t -> t.getType().equals("B")
    .collect(Collections.toList());

But I want to add an extra filter on each subtype and only match where "Z" exists

Solution

You can do:

myObjects.stream()
         .filter(t -> t.getType().equals(someotherType) && 
                      t.getSubTypes().stream().anyMatch(<predicate>))
         .collect(Collectors.toList());

This will get all MyObject objects

>Meets the criteria for type members. > The objects contained in the nested list < string > meet some other criteria, represented by < predicate >