为什么在注释处理器中评估伴生对象修饰符时它始终是私有的？

Question

我有一个自定义注释，它的 Retention 是 AnnotationRetention.SOURCE 我想确保注释的变量是 public static 但我在使用 kotlin 伴随对象时遇到问题，它们似乎是 private 即使我明确声明它们 public.

这是我的注释代码：

class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
}

companion object {
    @AZNEncryptor("the raw string")
    public var str: String? = null
}
}

我的注释处理器代码是：

    override fun process(set: Set<TypeElement>, roundEnvironment: RoundEnvironment): Boolean {        roundEnvironment.getElementsAnnotatedWith(AZNEncryptor::class.java).forEach { element ->

        if (element.getKind() != ElementKind.FIELD) {
            processingEnv.messager.printMessage(Diagnostic.Kind.ERROR, "this annotation can only be applied to the variables.")
            return true
        }


        val variableElement = element as VariableElement

        for(modifier in variableElement.modifiers)
        {
            processingEnv.messager.printMessage(Diagnostic.Kind.WARNING,  modifier.name)
        }

        if (!variableElement.modifiers.contains(Modifier.STATIC) || !variableElement.modifiers.contains(Modifier.PUBLIC)) {
            processingEnv.messager.printMessage(Diagnostic.Kind.ERROR, "the annotated variable must be a \"public static\"")
            return true
        }

        generateClass("constants", variableElement.simpleName.toString())

    return true
}

Answer 1

我发现了问题。当我反编译 kotlin 代码字节码时，我得到了这个 java 代码：

public final class MainActivity extends AppCompatActivity {
  @Nullable
  private static String str;

  .
  .
  .
 public static final class Companion {
  @Nullable
  public String getStr() {
     return MainActivity.str;
  }

  public void setStr(@Nullable String var1) {
     MainActivity.str = var1;
  }

  private Companion() {
  }

  // $FF: synthetic method
  public Companion(DefaultConstructorMarker $constructor_marker) {
     this();
  }
 }
}

如您所见，变量变为 private static。我只需要使用 @JvmField 来解决这个问题，现在反编译的字节码如下所示：

public final class MainActivity extends AppCompatActivity {
  @JvmField
  @Nullable
  public static String str;

  .
  .
  .
   public static final class Companion {
  private Companion() {
  }

  // $FF: synthetic method
  public Companion(DefaultConstructorMarker $constructor_marker) {
     this();
  }
  }
  }

为什么在注释处理器中评估伴生对象修饰符时它始终是私有的？

why companion object modifier is always private when i assess it in annotation processor?

android

kotlin

annotations

annotation-processing