(#) Using Blocked Private API !!! ERROR: Using Blocked Private API This is an error, and is also enforced at build time when supported by the build system. For Android this means it will run during release builds. Id : `BlockedPrivateApi` Summary : Using Blocked Private API Severity : Fatal Category : Correctness Platform : Android Vendor : Android Open Source Project Feedback : https://issuetracker.google.com/issues/new?component=192708 Since : 3.5.0 (August 2019) Affects : Kotlin and Java files Editing : This check runs on the fly in the IDE editor See : https://developer.android.com/preview/restrictions-non-sdk-interfaces Implementation : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-checks/src/main/java/com/android/tools/lint/checks/PrivateApiDetector.kt) Tests : [Source Code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/PrivateApiDetectorTest.kt) Usage of restricted non-SDK interface is forbidden for this targetSDK. Accessing non-SDK methods or fields through reflection has a high likelihood to break your app between versions, and is being restricted to facilitate future app compatibility. (##) Example Here is an example of lint warnings produced by this check: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~text src/test/pkg/TestReflection.java:12:Error: Reflective access to NETWORK_TYPES is forbidden when targeting API 28 and above [BlockedPrivateApi] Field deniedField = TelephonyManager.class.getDeclaredField("NETWORK_TYPES"); // ERROR 1 -------------------------------------------------------- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Here is the source file referenced above: `src/test/pkg/TestReflection.java`: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~java linenumbers package test.pkg; import android.content.Context; import android.telephony.TelephonyManager; import java.lang.reflect.Field; public class TestReflection { public void test(Context context, int subId) { try { TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); Field deniedField = TelephonyManager.class.getDeclaredField("NETWORK_TYPES"); // ERROR 1 Object o1 = deniedField.get(tm); Field allowedField = TelephonyManager.class.getDeclaredField("NETWORK_SELECTION_MODE_MANUAL"); // OK Object o2 = allowedField.get(tm); Field maybeField = TelephonyManager.class.getDeclaredField("OTASP_NEEDED"); // ERROR 2 Object o3 = maybeField.get(tm); } catch (ReflectiveOperationException e) { throw new IllegalStateException(e); } } } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You can also visit the [source code](https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:lint/libs/lint-tests/src/test/java/com/android/tools/lint/checks/PrivateApiDetectorTest.kt) for the unit tests for this check to see additional scenarios. The above example was automatically extracted from the first unit test found for this lint check, `PrivateApiDetector.testFields`. To report a problem with this extracted sample, visit https://issuetracker.google.com/issues/new?component=192708. (##) Suppressing You can suppress false positives using one of the following mechanisms: * Using a suppression annotation like this on the enclosing element: ```kt // Kotlin @Suppress("BlockedPrivateApi") fun method() { forName(...) } ``` or ```java // Java @SuppressWarnings("BlockedPrivateApi") void method() { forName(...); } ``` * Using a suppression comment like this on the line above: ```kt //noinspection BlockedPrivateApi problematicStatement() ``` * Using a special `lint.xml` file in the source tree which turns off the check in that folder and any sub folder. A simple file might look like this: ```xml <?xml version="1.0" encoding="UTF-8"?> <lint> <issue id="BlockedPrivateApi" severity="ignore" /> </lint> ``` Instead of `ignore` you can also change the severity here, for example from `error` to `warning`. You can find additional documentation on how to filter issues by path, regular expression and so on [here](https://googlesamples.github.io/android-custom-lint-rules/usage/lintxml.md.html). * In Gradle projects, using the DSL syntax to configure lint. For example, you can use something like ```gradle lintOptions { disable 'BlockedPrivateApi' } ``` In Android projects this should be nested inside an `android { }` block. * For manual invocations of `lint`, using the `--ignore` flag: ``` $ lint --ignore BlockedPrivateApi ...` ``` * Last, but not least, using baselines, as discussed [here](https://googlesamples.github.io/android-custom-lint-rules/usage/baselines.md.html).