How to use java stream to filter object?

How to use the filter in java to filter the complete object.
I am having an ArrayList that contains name and amount, I have another array of string that contains some string.

Now here how to filter and create a new ArrayList which contain only these two object which has arr elements.

I tried to use two methods .equals and .contains but it does not produce output.

List<Person> people = new ArayList<>();
people.add(new Person("Warren Buffett" , 90));
people.add(new Person("Jeff Bezos" , 180));
people.add(new Person("Bill Gates" , 140));
people.add(new Person("Mark" , 120));

String arr[]={"Mark" , "Bill Gates"};

List<Person> newPeople = people.stream().filter(person -> person.name.equals(arr))
List<Person> newPeople = people.stream().filter(person -> person.name.contains(arr)).collect(collectors.toList());

newPeople.forEach(person -> System.out.println(person.name));

Edit:

I should get the output as an array of an object that should contain Mark and Bill gates name and their amount

Below you can find working solution. Use streams to iterate by your args array to find first matching arg.

List<Person> newPeople = people.stream()
            .filter(person -> Stream.of(arr).anyMatch(s -> person.name.equals(s)))
            .collect(Collectors.toList());



newPeople.forEach(person -> System.out.println(person.name));
// Bill Gates
// Mark

You cannot do this person.name.contains(arr), rather you should be doing person.name.contains(arr[0]) OR person.name.contains(arr[1]).<br>
In order to do so, you might want to do nested iteration.

You can convert the array to a list; then use the List.contains() to check if the person.name is available in that list.

First convert the array.

String arr[]={"Mark" , "Bill Gates"};
List<String> names = Arrays.asList(arr);

Now, use the List.contains()

List<Person> newPeople 
   = people.stream().filter(
                             person -> names.contains(person.name)).collect(Collectors.toList()
                           );

Below is the full method after the update.

public static void main(String[] args) {

    List<Person> people = new ArrayList<>();
    people.add(new Person("Warren Buffett" , 90));
    people.add(new Person("Jeff Bezos" , 180));
    people.add(new Person("Bill Gates" , 140));
    people.add(new Person("Mark" , 120));

    String arr[]={"Mark" , "Bill Gates"};
    List<String> names = Arrays.asList(arr);

    List<Person> newPeople = people.stream().filter(person -> names.contains(person.name)).collect(Collectors.toList());

    newPeople.forEach(person -> System.out.println(person.name));

}

So you want a new list containing only the Person instancences which names appears in arr? Try do this:

List<Person> newPeople = people.stream()
    .filter(person -> arr.contains(person.name))
    .collect(collectors.toList());

The lambda variable "person" is referring to a single object contained in the people list, not to the list itself. So when you use person.name.equals(...) or person.name.contains(...) your are calling those methods on a string. Doing the reverse, as in my example, will give you the desired result; if not, let know and we'll dig dipper

edit:

I was assuming arr was a List, so before using my code you should consider to do te following

List<String> names = Arrays.asList(arr);

And then

List<Person> newPeople = people.stream()
.filter(person -> names.contains(person.name))
.collect(collectors.toList());

Assuming you're having that array passed by something else, if you're creating it you could just create a list and skipping the array "step"