The essential difference between lazy and a hungry man in a single case

The essential difference between lazy and a hungry man in a single case lies in the following points:

1, a hungry man type is thread-safe, in the creation of a class at the same time has created a static object for the system to use, not change later. Lazy type If you create an instance object without adding synchronized, the access to the object is not thread-safe.

2, from the realization of their biggest difference is lazy-type is delayed loading, he is in need of time to create objects, and a hungry man-type in the virtual machine when the start will be created, a hungry man-style without attention to multithreading problems, simple and clear, can be used. But it is the instance that was created when the class was loaded (one of the friends wrote the wrong one), so if it is a Factory mode, caching a lot of instances, then you have to consider the efficiency problem, because this class one load will all the instances are created without using a block.

The essential difference between lazy and a hungry man in a single case