使用 EnumTypeAdapter 时，将 proguard 与 GSON 和 RoboGuice 一起使用会失败

Question

当尝试将 EnumTypeAdapter 与 Proguard 一起使用时，会导致 Gson.getAdapter() 中出现 AssertionError。这个错误似乎是由于类型信息丢失......下面是所有相关的源代码：

例外：

03-18 13:27:12.905: ERROR/roboguice(12139): Throwable caught during background processing
    java.lang.AssertionError
    at com.google.gson.internal.bind.TypeAdapters$EnumTypeAdapter.<init>(Unknown Source)
    at com.google.gson.internal.bind.TypeAdapters$24.create(Unknown Source)
    at com.google.gson.Gson.getAdapter(Unknown Source)

正在使用的 EnumTypeAdapter：

public class OperationResultSerializer implements JsonDeserializer<OperationResult>, JsonSerializer<OperationResult> {

@Override
public OperationResult deserialize(JsonElement json, Type typeOfT, JsonDeserializationContext context) throws JsonParseException {
    int value = json.getAsJsonPrimitive().getAsInt();
    return OperationResult.values()[value];
}

@Override
public JsonElement serialize(OperationResult src, Type typeOfSrc, JsonSerializationContext context) {
    return new JsonPrimitive(src.ordinal());
}
}

我如何构建我的 GSON 对象：

            gson = new GsonBuilder()
                .registerTypeAdapter(Calendar.class, new WcfCalendarSerializer())
                .registerTypeAdapter(OperationResult.class, new OperationResultSerializer())
                .registerTypeAdapter(FieldName.class, new FieldNameSerializer())
                .registerTypeAdapter(MealType.class, new MealTypeSerializer())
                .create();

我的 ProGuard 配置：

#-dontusemixedcaseclassnames: Necessary when building on windows where x.class and X.class is the same file
-dontusemixedcaseclassnames

-keepattributes *Annotation*
-keepattributes Signature

# Preserve the special static methods that are required in all enumeration classes.
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep public class * extends android.app.Application
-keep public class * extends android.app.Activity
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep class * extends android.view.View { 
  public <init>(android.content.Context); 
  public <init>(android.content.Context, android.util.AttributeSet); 
  public <init>(android.content.Context, android.util.AttributeSet, int); 
  public void set*(...); 
}
-keep class com.google.inject.** { *; } 
-keep class javax.inject.** { *; } 
-keep class javax.annotation.** { *; } 
-keep class roboguice.** { *; } 

-keep class * extends android.preference.Preference { 
  public <init>(android.content.Context); 
  public <init>(android.content.Context, android.util.AttributeSet); 
  public <init>(android.content.Context, android.util.AttributeSet, int); 
  public void set*(...); 
}   

# Gson specific classes
-keep class sun.misc.Unsafe { *; }
#-keep class com.google.gson.stream.** { *; }

###Action bar sherlock 
-keep class android.support.v4.app.** { *; } 
-keep interface android.support.v4.app.** { *; } 
-keep class com.actionbarsherlock.** { *; } 
-keep interface com.actionbarsherlock.** { *; } 

###RoboGuice 
-keepclassmembers class * { 
    @com.google.inject.Inject <init>(...); 
} 
-keepclassmembers class * { 
    void *(**On*Event); 
} 
-keep public class roboguice.** 
-keep class com.google.inject.** 
-keep class com.google.gson.** {*;}

#datacontract
-keep public class com.ordering.datacontract.*
-keepclassmembers class com.ordering.datacontract.*

# LVL License binder class
-keep class com.android.vending.licensing.ILicensingService    


-dontwarn
-ignorewarnings

如前所述，我怀疑由于类型信息丢失而导致某些事情失败 - 在深入研究 GSON 源代码之后，这是为解析 EnumTypeAdapter 而调用的代码......显然 getEnumConstants 正在返回一个名称不作为 classOfT 类型的字段存在。但我不确定这怎么可能。

private static final class EnumTypeAdapter<T extends Enum<T>> extends TypeAdapter<T> {
private final Map<String, T> nameToConstant = new HashMap<String, T>();
private final Map<T, String> constantToName = new HashMap<T, String>();

public EnumTypeAdapter(Class<T> classOfT) {
  try {
    for (T constant : classOfT.getEnumConstants()) {
      String name = constant.name();
      SerializedName annotation = classOfT.getField(name).getAnnotation(SerializedName.class);
      if (annotation != null) {
        name = annotation.value();
      }
      nameToConstant.put(name, constant);
      constantToName.put(constant, name);
    }
  } catch (NoSuchFieldException e) {
    throw new AssertionError();
  }
}
public T read(JsonReader in) throws IOException {
  if (in.peek() == JsonToken.NULL) {
    in.nextNull();
    return null;
  }
  return nameToConstant.get(in.nextString());
}

public void write(JsonWriter out, T value) throws IOException {
  out.value(value == null ? null : constantToName.get(value));
}
  }

我已经搜索了所有可能的解决方案，但没有找到太多帮助。也许有人以前遇到过这种情况并可以指出我正确的方向？

Answer 1

我检查并检查了反编译的 APK。我认为这个问题与某些枚举类型在混淆过程中丢失其成员有关。

一定要保留枚举类成员：

-keepclassmembers enum * {
 public static **[] values();
 public static ** valueOf(java.lang.String);
 }

另外 - 确保 GSON 中使用的所有类都被保留：

 -keep public class com.company.ordering.datacontract.** {
 public protected *;
 }

 -keep public class com.company.ordering.service.request.** {
 public protected *;
 }
 -keep public class com.company.ordering.service.response.** {
 public protected *;
 }

查看完整配置@pastebin.com/r5Jg3yY2