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Android uses permissions to protect resources

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which applications can use cost-sensitive APIs, e.g. SMS

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protects user information

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system resources such as the camera

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permissions are represented as strings

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stored in AndroidManifest.xml file

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when application wants to use a permissions

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specifies a uses-permission tag in AndroidManifest.xml file

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when user installs, has to accept this permission

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in the earlier application, we access the contacts on the phone, here is how the app requrested the permission:

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Android applications can also define and enforce permissions

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e.g. your application performs a priviledged/dangerous operation

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you want to put a permission on it so other applications can't invoke it

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e.g. you have an app that formats an external memory card

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the application can be started just by touching icon

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AndroidManifest.xml file

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any other application that wants to use it will have to acquire the permission

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if it doesn't have permission

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second application

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will get permission error

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to fix that, add element:

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Android even allows you to set permission for components

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Activity permissions

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startActivity()

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startActivityForResult()

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Service Permissions

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Context.startService()

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Context.stopService()

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Context.bindService()

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BroadcastReceiver Permissions

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ContentProvider Permissions