java 8 stream filter list of object lists

Question

I want to filter by the object field

List<Book> = Arrays.asList<book1, book2, book3>;

class Book {
    String author;
    List<Language>;
}

class Language {
    String locale;
    int code;
}

Book book1 = new Book("author1", Arrays.asList(new Language("en", 1), new Language("fr", 3)));
Book book2 = new Book("author2", Arrays.asList(new Language("ca", 2), new Language("fr", 3)));
Book book3 = new Book("author3", Arrays.asList(new Language("en", 1)));

I want to have a list of the books which not contain Language en.

The result should be :

List<Book> = Arrays.asList<book1, book2>;

Book book1 = new Book("author1", Arrays.asList(new Language("fr", 3)));
Book book2 = new Book("author2", Arrays.asList(new Language("ca", 2), new Language("fr", 3)));

I tried to do this : but it not remove 'en' from book1

return books
        .stream()
        .filter(book -> book.getLanguages()
                .stream()
                .allMatch(value -> !"en".equals(value.getLanguage())))
        .collect(Collectors.toList());

Answer 1

First you can use filter to check any Language object has value of en and then use findFirst to get the matching Language object

return books.stream()
            .filter(book -> !book.getLanguages()
                  .stream()
                  .filter(value -> "en".equals(value.getLanguage()))
                  .findFirst().isPresent())
    .collect(Collectors.toList());