proper usage of synchronized singleton?

Question

So I am thinking about building a hobby project, one off kind of thing, just to brush up on my programming/design.

It\'s basically a multi threaded web spider, upda

Answer 1

The article you referenced only talks about making the creation of the singleton object, presumably a collection in this case, thread-safe. You also need a thread-safe collection so that the collection operations also work as expected. Make sure that the underlying collection in the singleton is synchronized, perhaps using a ConcurrentHashMap.