List.equals() 在覆盖 java.lang.Object.equals() 时是否执行了预期的行为？

Question

Let's say I have this ArrayList in a class:

private ArrayList<Integer> someList = new ArrayList<Integer>();

If I'm overriding the java.lang.equals() method in a class containing the ArrayList, and I want to compare if another Object's ArrayList is equal:

@Override
public boolean equals(Object o) {
  this.someList.equals(o.someList);
}

Would the ArrayList equals method work in comparing the size and contents of the other ArrayList, or would it just call the current overriden equals method?

Answer 1

The ArrayList instance calls it's equals method. The overwritten equals method can be called only from instances of your class. So the answer is yes, it will work in comparing the size and contents of the other ArrayList .