com.google.gson.internal.StringMap cannot be cast XXX（整理）

問題描述：

I am using Gson in my application and for that, i am using some classes with name as same as the one in using Json. My application works well, But while writing proguard, application crashes, I guess some of the classes are shrinking. my error is :

java.lang.ClassCastException: com.google.gson.internal.StringMap cannot be cast to com.sample.package.GsonClass
           

這哥們兒遇到的問題和我遇到的一樣，都是：

不混淆時正常運作，混淆之後卻會報異常，（異常格式如下：）

java.lang.ClassCastException: com.google.gson.internal.StringMap cannot be cast to XXX
           

問題的答案連結： http://stackoverflow.com/questions/16563916/proguard-issue-while-using-gson

解決方式如下：

You need to add these lines to your proguard so that gson class is kept while signing your app.

（就是說将以下内容添加到混淆檔案當中）

##---------------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  ----------
           

（此段代碼摘自 https://code.google.com/p/google-gson/source/browse/trunk/examples/android-proguard-example/proguard.cfg）

再混淆運作，就正常了