ComponentCaller


public final class ComponentCaller
extends Object

java.lang.Object
   ↳ android.app.ComponentCaller


Represents the app that launched the component. See below for the APIs available on the component caller.

Note, that in Build.VERSION_CODES.VANILLA_ICE_CREAM only Activity has access to ComponentCaller instances.

Summary

Public methods

int checkContentUriPermission(Uri uri, int modeFlags)

Determines whether this component caller had access to a specific content URI at launch time.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

String getPackage()

Returns the package name of this component caller.

int getUid()

Returns the uid of this component caller.

int hashCode()

Returns a hash code value for the object.

Inherited methods

Public methods

checkContentUriPermission

public int checkContentUriPermission (Uri uri, 
                int modeFlags)

Determines whether this component caller had access to a specific content URI at launch time. Apps can use this API to validate content URIs coming from other apps.

Note, in Build.VERSION_CODES.VANILLA_ICE_CREAM only Activity has access to ComponentCaller instances.

Before using this method, note the following:

Parameters
uri Uri: The content uri that is being checked This value cannot be null.

modeFlags int: The access modes to check Value is either 0 or a combination of Intent.FLAG_GRANT_READ_URI_PERMISSION, and Intent.FLAG_GRANT_WRITE_URI_PERMISSION

Returns
int PackageManager#PERMISSION_GRANTED if this activity caller is allowed to access that uri, or PackageManager#PERMISSION_DENIED if it is not Value is PackageManager.PERMISSION_GRANTED, or PackageManager.PERMISSION_DENIED

Throws
IllegalArgumentException if uri is a non-content URI or it wasn't passed at launch in Intent#getData(), Intent#EXTRA_STREAM, and Intent#getClipData()
SecurityException if you don't have access to uri

equals

public boolean equals (Object obj)

Indicates whether some other object is "equal to" this one.

The equals method implements an equivalence relation on non-null object references:

  • It is reflexive: for any non-null reference value x, x.equals(x) should return true.
  • It is symmetric: for any non-null reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
  • It is transitive: for any non-null reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
  • It is consistent: for any non-null reference values 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.
  • For any non-null reference value x, x.equals(null) should return false.

An equivalence relation partitions the elements it operates on into equivalence classes; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes.

Parameters
obj Object: This value may be null.

Returns
boolean true if this object is the same as the obj argument; false otherwise.

getPackage

public String getPackage ()

Returns the package name of this component caller.

Note, in Build.VERSION_CODES.VANILLA_ICE_CREAM only Activity has access to ComponentCaller instances.

Requirements for Activity callers

In order to receive the calling app's package name, at least one of the following has to be met:

  • The calling app must call ActivityOptions#setShareIdentityEnabled(boolean) with a value of true and launch this activity with the resulting ActivityOptions.
  • The launched activity has the same uid as the calling app.
  • The launched activity is running in a package that is signed with the same key used to sign the platform (typically only system packages such as Settings will meet this meet this requirement).
These are the same requirements for getUid(); if any of these are met, then these methods can be used to obtain the uid and package name of the calling app. If none are met, then null is returned.

Note, even if the above conditions are not met, the calling app's identity may still be available from Activity#getCallingPackage() if this activity was started with Activity#startActivityForResult to allow validation of the result's recipient.

Returns
String the package name of the calling app or null if the current component cannot access the identity of the calling app or the caller is invalid

getUid

public int getUid ()

Returns the uid of this component caller.

Note, in Build.VERSION_CODES.VANILLA_ICE_CREAM only Activity has access to ComponentCaller instances.

Requirements for Activity callers

In order to receive the calling app's uid, at least one of the following has to be met:

  • The calling app must call ActivityOptions#setShareIdentityEnabled(boolean) with a value of true and launch this activity with the resulting ActivityOptions.
  • The launched activity has the same uid as the calling app.
  • The launched activity is running in a package that is signed with the same key used to sign the platform (typically only system packages such as Settings will meet this requirement).
These are the same requirements for getPackage(); if any of these are met, then these methods can be used to obtain the uid and package name of the calling app. If none are met, then Process#INVALID_UID is returned.

Note, even if the above conditions are not met, the calling app's identity may still be available from Activity#getCallingPackage() if this activity was started with Activity#startActivityForResult to allow validation of the result's recipient.

Returns
int the uid of the calling app or Process#INVALID_UID if the current component cannot access the identity of the calling app or the caller is invalid

hashCode

public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns
int a hash code value for this object.