The java.lang.Iterator interface has 3 methods: hasNext, next and remove. In order to implement a read-only iterator, you have to provide an implementation for 2 of those: hasNext and next.

My problem is that these methods does not declare any exceptions. So if my code inside the iteration process declares exceptions, I must enclose my iteration code inside a try/catch block.

My current policy has been to rethrow the exception enclosed in a RuntimeException. But this has issues because the checked exceptions are lost and the client code no longer can catch those exceptions explicitly.

How can I work around this limitation in the Iterator class?

Here is a sample code for clarity:

class MyIterator implements Iterator
{
    @Override
    public boolean hasNext()
    {
        try
        {
            return implementation.testForNext();
        }
        catch ( SomethingBadException e ) 
        {
            throw new RuntimeException(e);
        }
    }

    @Override
    public boolean next()
    {
        try
        {
            return implementation.getNext();
        }

        catch ( SomethingBadException e ) 
        {
            throw new RuntimeException(e);
        }
    }

    ...
}