AudioSystem class acts as the entry point to the
sampled-audio system resources. This class lets you query and
access the mixers that are installed on the system.
AudioSystem includes a number of
methods for converting audio data between different formats, and for
translating between audio files and streams. It also provides a method
for obtaining a Line
directly from the
AudioSystem without dealing explicitly
with mixers.
Properties can be used to specify the default mixer for specific line types. Both system properties and a properties file are considered. In the Sun reference implementation, the properties file is "lib/sound.properties" in the JRE directory. If a property exists both as a system property and in the properties file, the system property takes precedence. If none is specified, a suitable default is chosen among the available devices. The syntax of the properties file is specified in Properties.load . The following table lists the available property keys and which methods consider them:
| Property Key | Interface | Affected Method(s) |
|---|---|---|
javax.sound.sampled.Clip |
Clip | #getLine , #getClip |
javax.sound.sampled.Port |
Port | #getLine |
javax.sound.sampled.SourceDataLine |
SourceDataLine | #getLine , #getSourceDataLine |
javax.sound.sampled.TargetDataLine |
TargetDataLine | #getLine , #getTargetDataLine |
String returned by the getName
method of Mixer.Info.
Either the class name, or the mixer name may be omitted.
If only the class name is specified, the trailing hash mark
is optional.
If the provider class is specified, and it can be
successully retrieved from the installed providers, the list of
Mixer.Info objects is retrieved
from the provider. Otherwise, or when these mixers
do not provide a subsequent match, the list is retrieved
from #getMixerInfo
to contain
all available Mixer.Info objects.
If a mixer name is specified, the resulting list of
Mixer.Info objects is searched:
the first one with a matching name, and whose
Mixer provides the
respective line interface, will be returned.
If no matching Mixer.Info object
is found, or the mixer name is not specified,
the first mixer from the resulting
list, which provides the respective line
interface, will be returned.
For example, the property javax.sound.sampled.Clip
with a value
"com.sun.media.sound.MixerProvider#SunClip"
will have the following consequences when
getLine is called requesting a Clip
instance:
if the class com.sun.media.sound.MixerProvider exists
in the list of installed mixer providers,
the first Clip from the first mixer with name
"SunClip" will be returned. If it cannot
be found, the first Clip from the first mixer
of the specified provider will be returned, regardless of name.
If there is none, the first Clip from the first
Mixer with name
"SunClip" in the list of all mixers
(as returned by getMixerInfo) will be returned,
or, if not found, the first Clip of the first
Mixerthat can be found in the list of all
mixers is returned.
If that fails, too, an IllegalArgumentException
is thrown.
NOT_SPECIFIED for such parameters. Other
methods may also accept or return this value, as documented.
The equals method implements an equivalence relation
on non-null object references:
x, x.equals(x) should return
true.
x and y, x.equals(y)
should return true if and only if
y.equals(x) returns true.
x, y, and z, if
x.equals(y) returns true and
y.equals(z) returns true, then
x.equals(z) should return true.
x and y, multiple invocations of
x.equals(y) consistently return true
or consistently return false, provided no
information used in equals comparisons on the
objects is modified.
x,
x.equals(null) should return false.
The equals method for class Object implements
the most discriminating possible equivalence relation on objects;
that is, for any non-null reference values x and
y, this method returns true if and only
if x and y refer to the same object
(x == y has the value true).
Note that it is generally necessary to override the hashCode method whenever this method is overridden, so as to maintain the general contract for the hashCode method, which states that equal objects must have equal hash codes.
File. The File must
point to valid audio file data.IOException.File. The File must
point to valid audio file data.IOException.Clip
object.
The returned clip must be opened with the
open(AudioFormat) or
open(AudioInputStream) method.
This is a high-level method that uses If the system property
getMixer
and javax.sound.sampled.Clip
is defined or it is defined in the file "sound.properties",
it is used to retrieve the default clip.
For details, refer to the class description
.
The returned clip must be opened with the
open(AudioFormat) or
open(AudioInputStream) method.
This is a high-level method that uses getMixer
and
Line.Info object.
If a DataLine is requested, and info
is an instance of DataLine.Info specifying at least
one fully qualified audio format, the last one
will be used as the default format of the returned
DataLine.
If system properties
javax.sound.sampled.Clip,
javax.sound.sampled.Port,
javax.sound.sampled.SourceDataLine and
javax.sound.sampled.TargetDataLine are defined
or they are defined in the file "sound.properties",
they are used to retrieve default lines.
For details, refer to the class description
.
If the respective property is not set, or the mixer
requested in the property is not installed or does not provide the
requested line, all installed mixers are queried for the
requested line type. A Line will be returned from the first mixer
providing the requested line type.
AudioFormat object. The returned line
will be provided by the default system mixer, or,
if not possible, by any other mixer installed in the
system that supports a matching
SourceDataLine object.
The returned line should be opened with the
open(AudioFormat) or
open(AudioFormat, int) method.
This is a high-level method that uses The returned If the system property
getMixer
and SourceDataLine's default
audio format will be initialized with format.
javax.sound.sampled.SourceDataLine
is defined or it is defined in the file "sound.properties",
it is used to retrieve the default source data line.
For details, refer to the class description
.
AudioFormat object, provided by the mixer
specified by the Mixer.Info object.
The returned line should be opened with the
open(AudioFormat) or
open(AudioFormat, int) method.
This is a high-level method that uses The returned getMixer
and SourceDataLine's default
audio format will be initialized with format.
AudioFormat object. The returned line
will be provided by the default system mixer, or,
if not possible, by any other mixer installed in the
system that supports a matching
TargetDataLine object.
The returned line should be opened with the
open(AudioFormat) or
open(AudioFormat, int) method.
This is a high-level method that uses The returned getMixer
and TargetDataLine's default
audio format will be initialized with format.
AudioFormat object, provided by the mixer
specified by the Mixer.Info object.
The returned line should be opened with the
open(AudioFormat) or
open(AudioFormat, int) method.
This is a high-level method that uses The returned If the system property
getMixer
and TargetDataLine's default
audio format will be initialized with format.
javax.sound.sampled.TargetDataLine
is defined or it is defined in the file "sound.properties",
it is used to retrieve the default target data line.
For details, refer to the class description
.
java.util.Hashtable.
The general contract of hashCode is:
hashCode method on each of
the two objects must produce the same integer result.
As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation technique is not required by the JavaTM programming language.)
Line.Info object. A line is supported if
any installed mixer supports it.wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
toString method returns a string that
"textually represents" this object. The result should
be a concise but informative representation that is easy for a
person to read.
It is recommended that all subclasses override this method.
The toString method for class Object
returns a string consisting of the name of the class of which the
object is an instance, the at-sign character `@', and
the unsigned hexadecimal representation of the hash code of the
object. In other words, this method returns a string equal to the
value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.AudioSystem.NOT_SPECIFIED.