Proguard:保持动态声明的方法

Question

我正在使用反射调用一个超出我的Android应用程序的目标API级别的方法:

try {
    Method m = Class.forName("android.content.Context")
            .getDeclaredMethod("getExternalCacheDir");
    Object result = m.invoke(this);
    if (result instanceof File) {
        Log.v("MyApp", "external cache: "
                + ((File) result).getAbsolutePath());
        cacheDirectory = (File) result;
    } else {
        Log.v("MyApp", "non-file cache: " + result);
    }
} catch (Exception e) {
    // ...
}

我可以通过Proguard毫无问题地优化它,但它警告我:

Note: com.example.MyApp accesses a declared method 'getExternalCacheDir()' dynamically
      Maybe this is library method 'android.content.Context { java.io.File getExternalCacheDir(); }'
      Maybe this is library method 'android.content.ContextWrapper { java.io.File getExternalCacheDir(); }'
      Maybe this is library method 'android.test.mock.MockContext { java.io.File getExternalCacheDir(); }'
Note: there were 1 accesses to class members by means of introspection.
      You should consider explicitly keeping the mentioned class members
      (using '-keep' or '-keepclassmembers').

这是一个实际问题,还是Proguard只是告诉我一个潜在的问题？

Answer 1

这与Paul Lammertsma发布的答案类似.另请参阅ProGuard Eric Lafortune的答案作者:如何抑制来自ProGuard的'可能这是程序方法'警告

您可以通过在配置中明确提及方法来避免它:

-keep class com.foo.OtherClass { com.foo.OtherClass getInstance(); }

或者,您可以抑制班级的注释:

-dontnote com.foo.MyClass