Don't try to access unsafe APIs on android 29+ (#913)

* Don't try to access unsafe APIs on android 29+

Resolves #872. Not sure if we want to try caching some of these lookups

* Checkstyle

* Use correct inner class naming

Co-Authored-By: Jake Wharton <jakew@google.com>

* Name variable ignored

* Cache android check
This commit is contained in:
Zac Sweers
2019-09-24 16:05:12 -04:00
committed by GitHub
parent 1e541fc66c
commit c0639316b1

View File

@@ -34,6 +34,9 @@ abstract class ClassFactory<T> {
abstract T newInstance() throws abstract T newInstance() throws
InvocationTargetException, IllegalAccessException, InstantiationException; InvocationTargetException, IllegalAccessException, InstantiationException;
private static volatile boolean androidChecked = false;
private static volatile boolean tryUnsafe = true;
public static <T> ClassFactory<T> get(final Class<?> rawType) { public static <T> ClassFactory<T> get(final Class<?> rawType) {
// Try to find a no-args constructor. May be any visibility including private. // Try to find a no-args constructor. May be any visibility including private.
try { try {
@@ -54,29 +57,45 @@ abstract class ClassFactory<T> {
// No no-args constructor. Fall back to something more magical... // No no-args constructor. Fall back to something more magical...
} }
// Try the JVM's Unsafe mechanism. if (!androidChecked) {
// public class Unsafe { try {
// public Object allocateInstance(Class<?> type); Class<?> androidBuildClass = Class.forName("android.os.Build$VERSION");
// } Field sdkIntField = androidBuildClass.getDeclaredField("SDK_INT");
try { int sdk = (int) sdkIntField.get(null);
Class<?> unsafeClass = Class.forName("sun.misc.Unsafe"); if (sdk >= 29) {
Field f = unsafeClass.getDeclaredField("theUnsafe"); tryUnsafe = false;
f.setAccessible(true);
final Object unsafe = f.get(null);
final Method allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class);
return new ClassFactory<T>() {
@SuppressWarnings("unchecked")
@Override public T newInstance() throws InvocationTargetException, IllegalAccessException {
return (T) allocateInstance.invoke(unsafe, rawType);
} }
@Override public String toString() { } catch (Exception ignored) {
return rawType.getName(); } finally {
} androidChecked = true;
}; }
} catch (IllegalAccessException e) { }
throw new AssertionError(); if (tryUnsafe) {
} catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException ignored) { // Try the JVM's Unsafe mechanism.
// Not the expected version of the Oracle Java library! // public class Unsafe {
// public Object allocateInstance(Class<?> type);
// }
try {
Class<?> unsafeClass = Class.forName("sun.misc.Unsafe");
Field f = unsafeClass.getDeclaredField("theUnsafe");
f.setAccessible(true);
final Object unsafe = f.get(null);
final Method allocateInstance = unsafeClass.getMethod("allocateInstance", Class.class);
return new ClassFactory<T>() {
@SuppressWarnings("unchecked")
@Override
public T newInstance() throws InvocationTargetException, IllegalAccessException {
return (T) allocateInstance.invoke(unsafe, rawType);
}
@Override public String toString() {
return rawType.getName();
}
};
} catch (IllegalAccessException e) {
throw new AssertionError();
} catch (ClassNotFoundException | NoSuchMethodException | NoSuchFieldException ignored) {
// Not the expected version of the Oracle Java library!
}
} }
// Try (post-Gingerbread) Dalvik/libcore's ObjectStreamClass mechanism. // Try (post-Gingerbread) Dalvik/libcore's ObjectStreamClass mechanism.