Rendering Multimedia Content - Beginning Java ME Platform - page 436

These states are

• Unrealized : An unrealized Player instance does not have the information it needs
about the resources it must acquire in order to function. Many Player methods,
including getContentType , setTimeBase , getTimeBase , setMediaTime , getControls , and
getControl , will fail if invoked on a Player in this state, and the Player will throw an
IllegalStateException .

• Realized : An unrealized player moves to the realized state when you invoke its
realize method. This transition can be a lengthy process as the Player instance
obtains system resources and works with the media content to determine its
content type or perform other operations. You can stop the realization process by
invoking the instance's deallocate method, but you must do so before the Player
instance finishes transitioning to the realized state; once realized, a Player instance
cannot return to the unrealized state.

• Prefetched : A realized player may still need to do additional time-consuming
processing such as fill media buffers from the network or obtain exclusive
resources such as a hardware codec. To do this, you invoke the Player instance's
prefetch method.

• Started : Once a Player instance has been realized and its contents and resources
have been prefetched, you can start playback by invoking the Player instance's
start method. 1 This causes the Player instance to transition to the started state.
While in the started state, the instance runs and renders multimedia data until you
stop it by invoking stop or until it runs out of data to render. Invoking stop on a
started Player instance returns it to the prefetched state.

• Closed : From any other state, you can force a Player instance to release its
resources and move to the closed state by invoking its close method. Once
placed in this state, you must not attempt to use the instance again; it's ready for
reclamation by the garbage collector, and all you should do is set any references
to it to null .

As they say, the devil's in the details, so let's look at some actual code that renders
multimedia and controls its playback.

Oddly, you can usually bring a realized Player instance directly to the started state by invoking its
start method. A lot of the tutorial examples you see on the Internet—including examples from Sun—
do this, but it's counter to the documentation that the MMAPI JSR provides, so I don't recommend it.

1.