Question

When you have to access a “member variable”/field in a class, is it good practice to access it directly or call the getter and setter? and why?

Answer 1

I see almost only benefits in making your fields private and only provide access through a getter and possibly a setter

• controlled access. If you only want to provide read access, or only write access you can only achieve this by using getters/setters
• if you want to fire PropertyChangeEvents for bean properties, you can include this code in your setter. Otherwise all calls which modify this field directly should trigger a change event as well
• I personally find it easier to discover in my IDE who modifies the field. The only direct access to the field is in the class (since it is a private field), and all external changes go through the setter. This allows for faster debugging than having to use a field watchpoint
• subclasses who want to do something extra when the field change can override the setter, call super.set and do something extra

The only possible drawback I can think of is that it requires a bit more code to write (for the getters and setters), and a bit more code for accessing the field from outside the class. But with the current IDEs is this a pretty lame excuse

Some extra literature:
link1, link2