proguard Missing type parameter

Question

i try obfuscate my code of android app with ProGuard. But after this my app give exception at running:

11-15 01:46:26.818: W/System.err(21810): java.lang.RuntimeException: Missing type parameter.
11-15 01:46:26.828: W/System.err(21810):    at da.<init>(Unknown Source)
11-15 01:46:26.828: W/System.err(21810):    at gc.<init>(Unknown Source)
11-15 01:46:26.828: W/System.err(21810):    at fx.f(Unknown Source)
11-15 01:46:26.828: W/System.err(21810):    at com.yourshows.activity.UnwatchedActivity.onResume(Unknown Source)

I checked a mapping file and found this:

com.google.gson.reflect.TypeToken -> da:

I think it's lines in my app like:

        Type mapType = new TypeToken<Map<Integer, WatchedEpisodes>>(){}.getType(); // define generic type
        jsData = gson.fromJson(r, mapType);

I can not understand what conclusions should I do? Do not use variable name less then three characters or what?

UPD: answer

Tolu

You can post an answer of your own, because questions like these may be automatically deleted. – Daisey

Answer 1

answer is: use this proguard.cfg

##---------------Begin: proguard configuration common for all Android apps ----------
-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontskipnonpubliclibraryclassmembers
-dontpreverify
-verbose
-dump class_files.txt 
-printseeds seeds.txt 
-printusage unused.txt 
-printmapping mapping.txt 
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*


-allowaccessmodification
-keepattributes *Annotation*
-renamesourcefileattribute SourceFile
-keepattributes SourceFile,LineNumberTable
-repackageclasses ''


-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService
-dontnote com.android.vending.licensing.ILicensingService


# Explicitly preserve all serialization members. The Serializable interface
# is only a marker interface, so it wouldn't save them.
-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}


# Preserve all native method names and the names of their classes.
-keepclasseswithmembernames class * {
    native <methods>;
}


-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}


-keepclasseswithmembernames class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}


# Preserve static fields of inner classes of R classes that might be accessed
# through introspection.
-keepclassmembers class **.R$* {
  public static <fields>;
}


# 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 * {
    public protected *;
}


-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}
##---------------End: proguard configuration common for all Android apps ----------


##---------------Begin: proguard configuration for Gson  ----------
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature


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


# Application classes that will be serialized/deserialized over Gson
-keep class com.google.gson.examples.android.model.** { *; }


##---------------End: proguard configuration for Gson  ----------

Big thanks to owner this project --> google-gson

---

UPD: google/gson has their example of proguard configuration for android applications.

see on github

They propose to use this template of configuration

##---------------Begin: proguard configuration for Gson  ----------
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature

# For using GSON @Expose annotation
-keepattributes *Annotation*

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

# Application classes that will be serialized/deserialized over Gson
-keep class com.google.gson.examples.android.model.** { *; }

##---------------End: proguard configuration for Gson  ----------

Tolu

lint says: use -keepclasseswithmembers instead of -keepclasseswithmembernames – Polecat

I really don't know why but I have copied all this and pasted to proguard-project.txt but the same error still occurred! – Doublestop

I don't know what proguard-project.txt is. But i use this settings in proguard.cfg. Maybe you used not correct file for settings up your obfuscator? Try to ask a new question with more detail. – Tolu

@Tolu I obfuscate my code with Eclipse that's why the config is saved in proguard-project.txt in default. And here is my question #18168888 – Doublestop

Answer 2

Since I didn't notice the link in the question at first, here are the specific lines mentioned in the thread needed to get GSON to work with Proguard:

# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature

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

# Application classes that will be serialized/deserialized over Gson
-keep class com.google.gson.examples.android.model.** { *; }

Shari

Answer 3

This issue can be solved by using a different way to create the TypeToken instance (for the parameterized type Map<Integer, WatchedEpisodes>):

Type collectionType = 
  TypeToken.get(
    $Gson$Types.newParameterizedTypeWithOwner(null,
      Map.class, Integer.class, WatchedEpisodes.class)).getType();

The next version of gson (I assume 2.8), will allow you to type this more easily:

Type collectionType =
  TypeToken.getParameterized(Map.class,
                             Integer.class,
                             WatchedEpisodes.class).getType();

Goodwife

I was having obfuscation problems recently, when I upgraded my Gradle Plugin from 7.x to 8.x. Changing from new TypeToken... to TypeToken.getParameterized... solved these issues! – Meperidine

Answer 4

The current answer didn't solve my problem. Here is my solution:

Add these lines to your proguard-rules.pro file:

##---------------Begin: proguard configuration for Gson  ----------
# Gson uses generic type information stored in a class file when working with fields. Proguard
# removes such information by default, so configure it to keep all of it.
-keepattributes Signature

# For using GSON @Expose annotation
-keepattributes *Annotation*

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

# Application classes that will be serialized/deserialized over Gson
-keep class PATH_TO_YOUR_MODELS_PACKAGE.models.** { *; }

# Prevent proguard from stripping interface information from TypeAdapter, TypeAdapterFactory,
# JsonSerializer, JsonDeserializer instances (so they can be used in @JsonAdapter)
-keep class * extends com.google.gson.TypeAdapter
-keep class * implements com.google.gson.TypeAdapterFactory
-keep class * implements com.google.gson.JsonSerializer
-keep class * implements com.google.gson.JsonDeserializer

# Prevent R8 from leaving Data object members always null
-keepclassmembers,allowobfuscation class * {
  @com.google.gson.annotations.SerializedName <fields>;
}

# Retain generic signatures of TypeToken and its subclasses with R8 version 3.0 and higher.
-keep,allowobfuscation,allowshrinking class com.google.gson.reflect.TypeToken
-keep,allowobfuscation,allowshrinking class * extends com.google.gson.reflect.TypeToken

##---------------End: proguard configuration for Gson  ----------

Important Note:

You should put all your models that work with gson in a package and exclude it from minify using this proguard rule:

 -keep class PATH_TO_YOUR_MODELS_PACKAGE.** { *; }

change it based on your package name. for example if your models are in com.example.models you should have this line:

 -keep class com.example.models.** { *; }

Knorring

Answer 5

Incorrect Import:

You might be using the TypeToken class from Guava (com.google.common.reflect.TypeToken) instead of Gson (com.google.gson.reflect.TypeToken). Ensure you're importing the correct class based on the library you're using.

Danidania