java.lang.Object | |
↳ | android.os.PowerManager.WakeLock |
Class lets you say that you need to have the device on.
Call release when you are done and don't need the lock anymore.
Any application using a WakeLock must request the android.permission.WAKE_LOCK
permission in an <uses-permission>
element of the application's manifest.
Public Methods | |||||||||||
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Makes sure the device is on at the level you asked when you created
the wake lock.
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Makes sure the device is on at the level you asked when you created
the wake lock.
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Release your claim to the CPU or screen being on.
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Sets whether this WakeLock is ref counted.
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Returns a string containing a concise, human-readable description of this
object.
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Protected Methods | |||||||||||
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Invoked when the garbage collector has detected that this instance is no longer reachable.
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Inherited Methods | |||||||||||
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From class
java.lang.Object
|
Makes sure the device is on at the level you asked when you created the wake lock.
Makes sure the device is on at the level you asked when you created the wake lock. The lock will be released after the given timeout.
timeout | Release the lock after the give timeout in milliseconds. |
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Release your claim to the CPU or screen being on.
It may turn off shortly after you release it, or it may not if there are other wake locks held.
Sets whether this WakeLock is ref counted.
Wake locks are reference counted by default.
value | true for ref counted, false for not ref counted. |
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Returns a string containing a concise, human-readable description of this object. Subclasses are encouraged to override this method and provide an implementation that takes into account the object's type and data. The default implementation is equivalent to the following expression:
getClass().getName() + '@' + Integer.toHexString(hashCode())
See Writing a useful
toString
method
if you intend implementing your own toString
method.
Invoked when the garbage collector has detected that this instance is no longer reachable. The default implementation does nothing, but this method can be overridden to free resources.
Note that objects that override finalize
are significantly more expensive than
objects that don't. Finalizers may be run a long time after the object is no longer
reachable, depending on memory pressure, so it's a bad idea to rely on them for cleanup.
Note also that finalizers are run on a single VM-wide finalizer thread,
so doing blocking work in a finalizer is a bad idea. A finalizer is usually only necessary
for a class that has a native peer and needs to call a native method to destroy that peer.
Even then, it's better to provide an explicit close
method (and implement
Closeable
), and insist that callers manually dispose of instances. This
works well for something like files, but less well for something like a BigInteger
where typical calling code would have to deal with lots of temporaries. Unfortunately,
code that creates lots of temporaries is the worst kind of code from the point of view of
the single finalizer thread.
If you must use finalizers, consider at least providing your own
ReferenceQueue
and having your own thread process that queue.
Unlike constructors, finalizers are not automatically chained. You are responsible for
calling super.finalize()
yourself.
Uncaught exceptions thrown by finalizers are ignored and do not terminate the finalizer thread. See Effective Java Item 7, "Avoid finalizers" for more.
Throwable |
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