Why cannot we synchronized public object to lock the memory for avoiding multi-thread access?
synchronized has nothing to do with locking memory, but controlling access to a block of code, which may access and change the memory/database/file contents, the integrity of which might be compromized by multi-thread simultaneous access or changes. Here, I intentionally missed how synchronized works, uses what kind of working mechanism. Read other part of the FAQ for that, please. public/private/protected access modifiers have no relationship with synchronized, even they share a word “access”. They are for encapsulation, in other words, information sharing or hiding. Like your family, you may want certain information to be public, some to be known only by your relatives or close friends, some to be kept only to your family members. Some might be kept to yourself only, hoho, a secret. They are different concepts and serve different purposes.
