UnmodifiableListExample.java

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

class Main {

    public static void main(String[] args) {
        Household household = new Household();
        final List<Person> people = household.getPeople();
        // will throw UnsupportedOperationException
        people.add(new Person("Avery Larsen"));
    }
}

class Person {

    private String name;

    Person(final String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

class Household {

    private List<Person> mPeople;

    public Household() {
        mPeople = new ArrayList<>();
    }

    public List<Person> getPeople() {
        return Collections.unmodifiableList(mPeople);
    }
}