Proguard removes Anonymous class in Anonymous class in Java

Question

I have a issue that Proguard is not working when you declare a anonymous class within a anonymous class. This is what it looks like in a basic example:

public class Class1 {
  public void function1 (){
     new Class2(){
        @Override
        public void function2(){
          new Class3(){
            @Override
            public void function3(){
              // do something
            }
          }
        }
     }
  }
}

During a gradle build script proguard is being executed. Now i get the following error:

 my.package.Class1$2$1: can't find enclosing method 'void function2()' in program class my.package.Class1$2

If I change the code to just have 1 "level" of anonymous classes proguard is finishing without errors. This works:

public class Class1 {
  public void function1 (){
      Class3 class3Instance = new Class3(){
            @Override
            public void function3(){
              // do something
            }
      }
      new Class2(){
        @Override
        public void function2(){
           //do something with class3Instance  
        }
     }
  }
}

The project is a android project, though as far as I know that should not matter.

I tried all different kind of -keep rules for Class1, but nothing worked. Is this not supported by Proguard or do I have to add a rule to get it to work?

UPDATE 1:

As requested the structure if the interface used for the anonymous classes. The interface for Class2 is defined as follows:

public class Class2IntefaceEnclosingClass {
    public interface Class2 {
        void function2();
    }
}

The interface for Class3 is slightly different:

public interface Class3IntefaceEnclosingInterface {
    interface Class3 {
        void function3();
    }
}

Note: I can not change the layout of the interfaces since they are provided by android.

Class2 must be extending some class (say Foo). You can have keep clause some thing like this. -keep class * extends Foo {public void function2;} — user3161880, Sep 27 '16 at 10:00
Class2 implements a interface. Which is in turn defined as a inner interface of a interface (It is from Android). I tried: `-keep class * extends package.OuterInterface { *; }` and `-keep class * extends package.OuterInterface.InnerInterface { *; }` and `-keep class * extends package.OuterInterface$InnerInterface { *; }`. I also activated `-keepattributes InnerClasses`. No luck unfortunately. — Arne Fischer, Sep 27 '16 at 11:11
Could you please share the exact structure of the interface and its usage, to understand the nesting. (Exact fully qualified names are not expected) — user3161880, Sep 28 '16 at 07:00
Please try adding below keep options. `-keep interface your.package.Class2IntefaceEnclosingClass$Class2 {*;}` and `-keep interface your.package.Class3IntefaceEnclosingInterface$Class3 { *;}`. Let me know if it works. — user3161880, Sep 29 '16 at 06:14

score 1 · Answer 1 · answered Jan 17 '17 at 11:20

You can try to use @Keep annotation above function1(), function2() and function3().

public class Class1 {
  @Keep
  public void function1 (){
     new Class2(){
        @Keep
        @Override
        public void function2(){
          new Class3(){
            @Keep
            @Override
            public void function3(){
              // do something
            }
          }
        }
     }
  }
}

Proguard removes Anonymous class in Anonymous class in Java

1 Answers1