Filter nested lists using lambda

Question

I have one List<User> users. I would like to filter the list based on two conditions.

• UserID Compliance

• Filter Name Matching

  Public class The user implements Entity {

      public User() {
      }
  
      private String userName;
      private String userId;
      private List<Filter> filters;
  
      public String getUserName() {
          return userName;
      }
  
      public void setUserName(String userName) {
          this.userName = userName;
      }
  
      public String getUserId() {
          return userId;
      }
  
      public void setUserId(String userId) {
          this.userId = userId;
      }
  
      public List<Filter> getFilters() {
          return filters;
      }
  
      public void setFilters(List<Filter> filters) {
          this.filters = filters;
      }
  
  }
  

Here is the method signature

List<User> users = getUsersList();
public List<User> query(String userID,String filterName){
    users.stream().filter(element -> element.getUserID().equals(userID) && element.getFilters().stream().filter(f -> f.getFilterName().equals(filterName))).collect(Collectors.toList());

}

The above method does not work as I am filtering based on element and stream. Can someone help me with the correct way to filter lists and nested lists.

I also tried this way

users.stream().filter(e -> e.getUserId().equals(predicate.getUserID())).collect(Collectors.toList()).stream().filter(f -> f.getFilters().stream().filter(fe -> fe.getName().equals(predicate.getFilterName()))).collect(Collectors.toList());

anyway i get the error below

Type mismatch: cannot convert from Stream to boolean

Tried the offer of Adiel Loingers. He worked

java.util.function.Predicate<Filter> con = e -> e.getName().equals(predicate.getFilterName());
            result = users.stream().filter(p -> p.getUserId().equals(predicate.getUserID()) && p.getFilters().stream().anyMatch(con)).collect(Collectors.toList());

Answer 1

You have to change

element.getFilters().stream().filter(f -> f.getFilterName().equals(filterName))

to

element.getFilters().stream().anyMatch(f -> f.getFilterName().equals(filterName))

boolean true , , filter .

Answer 2

, , , , , true, false.

users.stream()
        .filter(element -> element.getUserId().equals(userId)
            && element.getFilters().stream().filter(f -> f.filterName.equals(FilterName)).findAny().isPresent())
        .collect(Collectors.toList());