What is the difference between getDefaultInstance() and getInstance() in Session class?

Question

What is the difference between Session.getDefaultInstance(props, authenticator) and getInstance(props, authenticator)? In general, when will you choos

Answer 1

For me, it was very important to use getInstance() instead of getDefaultInstance().

Because after mail session properties was changed, mail session still was storing old properties.

So getDefaultInstance() - it is looks like Singleton.

As docs said:

Note also that the Properties object is used only the first time this method is called, when a new Session object is created. Subsequent calls return the Session object that was created by the first call, and ignore the passed Properties object. Use the getInstance method to get a new Session object every time the method is called.