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.
See also:
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:
- You must have access to the supplied URI, otherwise it will throw a
SecurityException
. - This is not a real time check, i.e. the permissions have been computed at launch time.
- This method will return the correct result for content URIs passed at launch time,
specifically the ones from
Intent#getData()
,Intent#EXTRA_STREAM
, andIntent#getClipData()
in the intent ofstartActivity(intent)
. For others, it will throw anIllegalArgumentException
.
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 returntrue
. - It is symmetric: for any non-null reference values
x
andy
,x.equals(y)
should returntrue
if and only ify.equals(x)
returnstrue
. - It is transitive: for any non-null reference values
x
,y
, andz
, ifx.equals(y)
returnstrue
andy.equals(z)
returnstrue
, thenx.equals(z)
should returntrue
. - It is consistent: for any non-null reference values
x
andy
, multiple invocations ofx.equals(y)
consistently returntrue
or consistently returnfalse
, provided no information used inequals
comparisons on the objects is modified. - For any non-null reference value
x
,x.equals(null)
should returnfalse
.
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 oftrue
and launch this activity with the resultingActivityOptions
. - 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).
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 oftrue
and launch this activity with the resultingActivityOptions
. - 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).
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 inequals
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 thehashCode
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 thehashCode
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. |