错误警告：PackageInfo 中的 [deprecation] 签名已被弃用 (Signature signature:info.signatures)

Question

I getting these errors while I'm compiling.

This is the log,

> Task :app:compileDebugJavaWithJavac
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:198: warning: [deprecation] FusedLocationApi in LocationServices has been deprecated
        mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
                                        ^
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:249: warning: [deprecation] isGooglePlayServicesAvailable(Context) in GooglePlayServicesUtil has been deprecated
                .isGooglePlayServicesAvailable(this);
                ^
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:251: warning: [deprecation] isUserRecoverableError(int) in GooglePlayServicesUtil has been deprecated
            if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
                                      ^
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:252: warning: [deprecation] getErrorDialog(int,Activity,int) in GooglePlayServicesUtil has been deprecated
                GooglePlayServicesUtil.getErrorDialog(resultCode, this,
                                      ^
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:426: warning: [deprecation] GET_SIGNATURES in PackageManager has been deprecated
            PackageInfo info = getPackageManager().getPackageInfo(getPackageName() , PackageManager.GET_SIGNATURES);
                                                                                                   ^
C:\Users\HP\Desktop\FoodieRiderv1.0\FoodieRider1.1.1\FoodiesRider\app\src\main\java\com\foodies\rider\ActivitiesAndFragments\Activities\SplashScreenActivity.java:427: warning: [deprecation] signatures in PackageInfo has been deprecated
            for(Signature signature:info.signatures)
                                        ^
6 warnings

Can someone please explain what it means?

Answer 1

It means that those methods and classes have been Deprecated .

The people who have provided the method or class are flagging that they intend to remove them in a future release of ... whatever library it is that is currently providing them. The warning is to tell you that you would be advised to modify this code to use alternatives to those methods.

Typically, the deprecation notice (in the javadocs) will suggest some alternatives. For example the javadocs for GooglePlayServicesUtil.getErrorDialog says:

This method is deprecated.

Use getErrorDialog(Activity, int, int, OnCancelListener) instead.

Note that these are only warnings. You can ignore them for the time being, though they may present problems in the future.