It is sometimes useful to suspend execution of a thread. For example, a separate thread can be used to display the time of day. If the user does not desire a clock, then its thread can be suspended. Whatever the case, it is a simple matter to suspend a thread. Once suspended, it is also a simple matter to restart the thread.
The mechanisms to suspend, stop, and resume threads differ between early versions of Java and more modern versions, beginning with Java 2. Prior to Java 2, a program used suspend( ), resume( ), and stop( ), which are methods defined by Thread, to pause, restart, and stop the execution of a thread. They have the following forms:
final void resume( )
final void suspend( )
final void ...