Predefinied exception vs exception class

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Java

exceptions

I was defining a new type of Exception to 'replace' IndexOutOfBounds exception. In first instance I defined a new Class:

public class NoNextItemException extends Exception {
    public NoNextItemException(String message) {
        super(message);
    }

    public NoNextItemException() {
        super("No more elements in the queue");
    }
}

I think you can expect what is this exception for. I implemented the code for the queue like this:

public double peek() throws NoNextItemException {
    if (dataPointer == addPointer) {
        throw new NoNextItemException();

    } else {
        if (dataPointer == cola.length)
            dataPointer = 0;

        return cola[dataPointer];
    }
}

public double next() {
    double value = peek();
    dataPointer++;
    return value;
}

What I have tried:

Now Java raises an error because it's an unhandled exception in next() method. BUT if in NoNextItemException I do inherit from IndexOutOfBoundsException (or simply replace NoNextItemException for it) it doesn't raise any error, so I just have to handle the exception in peek() method.

So, IndexOutOfBoundsException (or any other predefined java exception type) doesn't force you to handle the exception every time you use methods that raises it but Exception does. Why is this due to?