A line can have controls, such as gain, pan, and reverb.
The controls themselves are instances of classes that extend the
base Control class.
The Line interface provides two accessor methods for
obtaining the line's controls: getControls returns the
entire set, and getControl returns a single control of
Lines exist in various states at different times. When a line opens, it reserves system
resources for itself, and when it closes, these resources are freed for
other objects or applications. The isOpen() method lets
you discover whether a line is open or closed.
An open line need not be processing data, however. Such processing is
typically initiated by subinterface methods such as
You can register an object to receive notifications whenever the line's
state changes. The object must implement the LineListener
interface, which consists of the single method
This method will be invoked when a line opens and closes (and, if it's a
DataLine , when it starts and stops).
An object can be registered to listen to multiple lines. The event it
receives in its update method will specify which line created
the event, what type of event it was
(OPEN, CLOSE, START, or STOP),
and how many sample frames the line had processed at the time the event occurred.
Certain line operations, such as open and close, can generate security
exceptions if invoked by unprivileged code when the line is a shared audio