Getting only required objects from a list using Java 8 Streams

Question

Consider a Parent class with the attributes attrib1, attrib2 and List child with its corresponding getters and s

Answer 1

As I can understand you should add additional filter for child lists:

 parent.stream().filter(e -> e.getChild().stream().anyMatch(c -> c.getAttrib1() > 10)).forEach(e -> e.setChild(e.getChild().stream().filter(c -> c.getAttrib1 > 10).collect(toList())))

If you have not setChild:

• You can remove items from lists
• Create completly new parent objects

To remove you can use iterator:

parent.stream().filter(e -> e.getChild().stream().anyMatch(c -> c.getAttrib1 > 10))
   .forEach(e -> {
      for(Iterator it = e.getChild().iterator(); it.hasNext();){
          Child cur = it.next();
          if(cur.getAttrib1() <= 10) it.remove();
    }
})