The java.util.list is not thread safe by default. There can be situations where you would want to use the list in a multithreaded environment for processing.

An effective mechanism is to use Collections.synchronizedList(ordinaryList) where ordinaryList is a normal list. The return value of this invocation is a thread safe list which can be used as desired.

// Creating a safeList that will be thread safeList safeList = Collections.synchronizedList(ordinaryList);