How do I return a boolean if a value is present in a list inside a list using java 8

I have a List of objects, which contains a list of Strings. I want to return true if the 'names' list is not null and has size more than 1.

Consider the below code

class Obj {
  private List<String> names;
}
class Test {
  private List<Obj> objs;
  public boolean isPresent(String name) {
  //Loop through the list of lists
 }
}

Here I want to determine if 'names' is not null and has size more than 1 for any of the 'objs' objects. Is there a way we can do this using Streams in java 8?

Preface

Your requirements are a bit unclear. You're requirements could be read both as

• Return true if any names array has greater than 1, or
• Return true if all the names arrays are greater than 1

> Remember, there is a names array for each node in the objs list.

Code

If you want to return true if any node in the names lists are greater than 1 then you would use the boolean java.util.stream.Stream.anyMatch(Predicate<? super Obj> predicate) method.

  public boolean isPresent() {
	  return objs.stream().anyMatch( o -> o.getNames().size() > 1 );
 }

If you want to return true only in the case where all the nodes are greater than 1, and therefore not null, you would use the boolean java.util.stream.Stream.allMatch(Predicate<? super Obj> predicate) method

  public boolean isPresent() {
	  return objs.stream().allMatch( o -> o.getNames().size() > 1 );
 }