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---
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layout: page
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title: "Error Handling"
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category: docs
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order: 9
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date: 2018-12-20 20:02:31
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disqus: 1
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---
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Errors are posted to the registered `CameraListener`s callback:
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```java
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@Override
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public void onCameraError(CameraException error) {
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// Got error!
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};
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```
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You are supposed to inspect the `CameraException` object as it contains useful information about
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what happened and what should be done, if anything. All things that fail can end up throwing this
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exception, which includes temporary actions like taking a picture, or functional actions like
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starting the camera preview.
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### Unrecoverable errors
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You can exclude unrecoverable errors using `CameraException.isUnrecoverable()`.
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If this function returns true, at this point the camera has been released and it is likely showing
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a black preview. The operation can't go on.
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You can try to call `camera.start()` again, but that's not guaranteed to work. For example, the
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camera sensor might be in use by another application, so there's nothing we could do.
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### Other errors
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For more fine grained control over what happened, inspect the reason using `CameraException.getReason()`.
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This will return one of the `CameraException.REASON_` constants:
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|Constant|Description|Unrecoverable|
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|--------|-----------|-------------|
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|`REASON_UNKNOWN`|Unknown error. No other info available.|No|
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|`REASON_FAILED_TO_CONNECT`|Failed to connect to the camera service.|Yes|
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|`REASON_FAILED_TO_START_PREVIEW`|Failed to start the camera preview.|Yes|
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|`REASON_DISCONNECTED`|Camera was forced to disconnect by the system.|Yes|
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|`REASON_PICTURE_FAILED`|Could not take a picture or picture snapshot.|No|
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|`REASON_VIDEO_FAILED`|Could not take a video or video snapshot.|No|
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|`REASON_NO_CAMERA`|Could not find a camera for this `Facing` value. You can try another.|No|
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