Handling ClassCastException When Using Java 17's Stream API with Custom Objects
Could someone explain I'm confused about Quick question that's been bugging me - I am encountering a `ClassCastException` when using the Stream API in Java 17 on a list of custom objects. I have a class `Person` that implements `Comparable<Person>`, and I am trying to sort a list of `Person` objects by their `age`. Here’s the relevant code snippet: ```java import java.util.*; class Person implements Comparable<Person> { private String name; private int age; public Person(String name, int age) { this.name = name; this.age = age; } public int getAge() { return age; } @Override public int compareTo(Person other) { return Integer.compare(this.age, other.age); } } public class Main { public static void main(String[] args) { List<Person> people = Arrays.asList( new Person("Alice", 30), new Person("Bob", 20), new Person("Charlie", 25) ); List<Person> sortedPeople = people.stream() .sorted() .collect(Collectors.toList()); sortedPeople.forEach(person -> System.out.println(person.getAge())); } } ``` When I run this code, I receive the following error message: ``` Exception in thread "main" java.lang.ClassCastException: class Person cannot be cast to class java.lang.Comparable ``` I’ve ensured that my `Person` class implements `Comparable<Person>` correctly. I also verified that I am using Java 17 and that my IDE is set to the correct version. I even tried using a comparator explicitly: ```java sortedPeople = people.stream() .sorted(Comparator.comparing(Person::getAge)) .collect(Collectors.toList()); ``` This also throws the same `ClassCastException`. I am puzzled because this works with standard objects like `Integer` and `String`. What could be causing this issue, and how can I resolve it? Is there something specific I need to do with custom classes in Java 17 when using the Stream API? I'm working on a application that needs to handle this. I'd really appreciate any guidance on this. I'm coming from a different tech stack and learning Java. I'm open to any suggestions.