使用启用了 proguard 的 GSON

Question

我的代码在没有 proguard 的情况下可以完美运行，但是在启用 proguard 时 GSON 不起作用。

这是代码中不起作用的部分

JSONArray mensaje = response.getJSONArray("categorias");
// Parsear con Gson
Categorias[] categorias = gson.fromJson(mensaje.toString(), Categorias[].class);
Log.d("mainfragment","desc categoria "+categorias[0].getDescripcionCategoria());

mainfragment 的日志打印为 null

# Output
D/Dato categorias﹕ Respuesta: {"categorias":[{"idCategoria":"22","imagenCategoria":"ic_aseguradora","descripcionCategoria":"Aseguradoras"},{"idCategoria":"24","imagenCategoria":"ic_bar","descripcionCategoria":"Bares"},{"idCategoria":"12","imagenCategoria":"ic_boutique","descripcionCategoria":"Boutiques"},{"idCategoria":"6","imagenCategoria":"ic_cafe","descripcionCategoria":"Cafeterias"},{"idCategoria":"21","imagenCategoria":"ic_ciber","descripcionCategoria":"Ciber"},{"idCategoria":"10","imagenCategoria":"ic_estetica","descripcionCategoria":"Estéticas"},{"idCategoria":"1","imagenCategoria":"ic_farmacia","descripcionCategoria":"Farmacias"},{"idCategoria":"7","imagenCategoria":"ic_ferreteria","descripcionCategoria":"Ferreterias"},{"idCategoria":"16","imagenCategoria":"ic_gas","descripcionCategoria":"Gas"},{"idCategoria":"23","imagenCategoria":"ic_gasolinera","descripcionCategoria":"Gasolineras"},{"idCategoria":"4","imagenCategoria":"ic_gym","descripcionCategoria":"Gimnasios"},{"idCategoria":"2","imagenCategoria":"ic_hotel","descripcionCategoria":"Hoteles"},{"idCategoria":"15","imagenCategoria":"ic_lavanderia","descripcionCategoria":"Lavanderias"},{"idCategoria":"19","imagenCategoria":"ic_muebleria","descripcionCategoria":"Mueblerias"},{"idCategoria":"25","imagenCategoria":"ic_optica","descripcionCategoria":"Ópticas"},{"idCategoria":"20","imagenCategoria":"ic_pasteleria","descripcionCategoria":"Pastelerias"},{"idCategoria":"17","imagenCategoria":"ic_pizza","descripcionCategoria":"Pizzerías"},{"idCategoria":"13","imagenCategoria":"ic_purificadora","descripcionCategoria":"Purificadoras de agua"},{"idCategoria":"5","imagenCategoria":"ic_restaurant","descripcionCategoria":"Restaurantes"},{"idCategoria":"11","imagenCategoria":"ic_ropa","descripcionCategoria":"Ropa"},{"idCategoria":"9","imagenCategoria":"ic_salon","descripcionCategoria":"Salones de fiestas"},{"idCategoria":"3","imagenCategoria":"ic_sonido","descripcionCategoria":"Sonidos"},{"idCategoria":"28","imagenCategoria":"ic_taqueria","descripcionCategoria":"Taquería"},{"idCategoria":"8","imagenCategoria":"ic_taxi","descripcionCategoria":"Taxis"},{"idCategoria":"14","imagenCategoria":"ic_tortilleria","descripcionCategoria":"Tortillerias"},{"idCategoria":"27","imagenCategoria":"ic_veterinaria","descripcionCategoria":"Veterinarias"},{"idCategoria":"18","imagenCategoria":"ic_vinateria","descripcionCategoria":"Vinaterías"},{"idCategoria":"26","imagenCategoria":"ic_zapateria","descripcionCategoria":"Zapaterías"}],"estado":1}
D/mainfragment﹕ desc categoria null

这是我的proguard规则

#GoogleMaps
-keep class * extends java.util.ListResourceBundle {
    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @ccom.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}



#Volley?

-optimizationpasses 5
-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*


-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

-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();
 }


 -keepclasseswithmembernames class * {
     native <methods>;
 }


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


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


-keepclassmembers class **.R$* {
   public static <fields>;
 }

 -keepclassmembers class * extends android.app.Activity {
    public void *(android.view.View);
 }


 -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 *;
 }

 -keep class android.support.v7.widget.SearchView
 -keep class android.support.v7.widget.**{*;}
 -keep class android.support.v4.app.** { *; }
 -keep interface android.support.v4.app.** { *; }
 -keep class com.actionbarsherlock.** { *; }
 -keep interface com.actionbarsherlock.** { *; }
 -keep class com.android.volley.** { *; }
 -keep interface com.android.volley.** { *; }
 -keepattributes *Annotation*


##---------------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*
-keepattributes EnclosingMethod

# 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 Categorias.data.model.** { *; }
 -keep class Categorias.** { *; }

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

# Add the gson class
-keep public class com.google.gson

# Add any classes the interact with gson
-keep class com.puertosoft.appcomercialdelpuerto.models.ChatModel { *; }
-keep class com.puertosoft.appcomercialdelpuerto.models.FeedModel { *; }
-keep class com.puertosoft.appcomercialdelpuerto.android.models.ChatModel { *; }
-keep class com.puertosoft.appcomercialdelpuerto.android.models.FeedModel { *; }

-libraryjars /build/intermediates/pre-dexed/debug/gson-2.3-08958b96da94c86264ec30e35a9d524bac95d2df.jar




-printmapping outputfile.txt
-renamesourcefileattribute SourceFile
#-keepattributes SourceFile,LineNumberTable

这是受影响的类

public class Categorias {

    private String idCategoria;
    private String descripcionCategoria;
    private String imagenCategoria;

    public Categorias(String idCategoria, String descripcionCategoria, String imagenCategoria){
        this.idCategoria=idCategoria;
        this.descripcionCategoria=descripcionCategoria;
        this.imagenCategoria=imagenCategoria;
    }

    public String getIdCategoria(){
        return idCategoria;
    }

    public String getDescripcionCategoria(){
        return descripcionCategoria;
    }

    public String getImagenCategoria(){
        return imagenCategoria;
    }

}

Answer 1

变量名会被 proguard 混淆，留下类似的东西

private String a;

而不是

private String descripcionCategoria;

您可以添加 proguard 规则，这样某些类就不会被混淆。我用这些侥幸逃脱了：

-keepattributes Signature
# POJOs used with GSON
# The variable names are JSON key values and should not be obfuscated
-keepclassmembers class com.example.apps.android.Categorias { <fields>; }
# You can apply the rule to all the affected classes also
# -keepclassmembers class com.example.apps.android.model.** { <fields>; }

如果你的 POJO 类名也用于解析，那么你也应该添加规则

-keep class com.example.apps.android.model.** { <fields>; }

在你的情况下，没有使用注释，如果你这样做，你会需要这个

# Keep the annotations
-keepattributes *Annotation*

---

另一种解决此问题的方法是使用SerializedName 注释并让类被混淆。为此，您仍然需要 -keepattributes *Annotation* 规则。

import com.google.gson.annotations.SerializedName

@SerializedName("descripcionCategoria")
private String descripcionCategoria;

Answer 2

如果您希望您的模型仍然被混淆，请使用注释 @SerializedName("name_of_json_field")。它会让 gson 知道该字段的真实名称。

相信你也会需要

-keepattributes *Annotation*

防止您的注释被混淆

Answer 3

您需要排除模型类的混淆，如下所示，我排除了 in.intellicode.webservices.models 包中的所有模型类

-keep class in.intellicode.webservices.models.** { *; }
-keep class in.intellicode.models.** { *; }
-keep class in.intellicode.events.*{ *; }

-keepattributes Signature
-keepattributes *Annotation*
-keep class sun.misc.Unsafe { *; }

Answer 4

当您将 proguard 脚本应用到模型类时，它会混淆它们的名称和属性名称。所以在混淆String descripcionCategoria; 之后你会得到类似String aaaa;的东西

Gson 通过 java 反射工作，它会在解析数据时尝试使用属性名称。因此，在对模型类应用混淆后，您将无法解析数据。

因此，从您的 proguard 脚本中排除模型类，您将能够再次解析。

Answer 5

使用proguard-rules 默认规则Gson

# 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 com.google.gson.examples.android.model.** { <fields>; }

# 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

来源：https://github.com/google/gson/blob/master/examples/android-proguard-example/proguard.cfg

Answer 6

改变这个

proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'

这对我有用

 proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'

在您应用的 build.gradle 文件中。

仅供参考， https://developer.android.com/studio/build/shrink-code