Proguard obfuscation is breaking simplexml

Viorel picture Viorel · Aug 28, 2012 · Viewed 7.4k times · Source

I am using simplexml in my android project, and everything works fine until I obfuscate the code. Then, errors start pouring in.

Part of the XML is as follows:

<categories success="true">
  <category id="102" caption="Magazin" parent="0" num_mags="114" >
    <category id="15" caption="Kunst" parent="102" num_mags="13" >
      <category id="17" caption="Design" parent="15" num_mags="10" ></category>
      <category id="18" caption="Haute+Couture" parent="15" num_mags="2" >
...

I have two classes: CategoryItemList:

@Root(name = "categories")
public class CategoryItemList {

    private final List<CategoryItem> mCategoryItems;
    /**
     * Create a new category items list.
     * 
     * @param categoryItems the list of category items
     */
    public CategoryItemList(@ElementList(name = "category", inline = true) final List<CategoryItem> categoryItems) {
        mCategoryItems = categoryItems;
    }
    @ElementList(name = "category", inline = true)
    public List<CategoryItem> getCategoryItems() {
        return mCategoryItems;
    }
}

and CategoryItem:

@Root(name = "category")
public class CategoryItem {
    private final int mId;
    private final String mCaption;
    private final int mParent;
    private final int mNumberOfMagazines;
    private final ArrayList<CategoryItem> mSubCategoryItems;
    /**
     * Creating a new category item.
     * 
     * @param id the category id
     * @param caption the name of category
     * @param parent the parent category
     * @param numMags the number of magazines from that category
     */
    public CategoryItem(@Attribute(name = "id") final int id,
                        @Attribute(name = "caption") final String caption,
                        @Attribute(name = "parent") final int parent,
                        @Attribute(name = "num_mags") final int numMags,
                        @ElementList(name = "category", inline = true, required = false) final ArrayList<CategoryItem> subCategoryItems) {
        mId = id;
        mCaption = caption;
        mParent = parent;
        mNumberOfMagazines = numMags;
        mSubCategoryItems = subCategoryItems;
    }

    @Attribute(name = "id")
    public int getId() {
        return mId;
    }

    @Attribute(name = "caption")
    public String getCaption() {
        String categoryName = null;

        try {
            categoryName = URLDecoder.decode(mCaption, "UTF-8");
        } catch (final UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return categoryName;
    }

    @Attribute(name = "parent")
    public int getParentId() {
        return mParent;
    }

    @Attribute(name = "num_mags")
    public int getNumbersOfMagazines() {
        return mNumberOfMagazines;
    }

    @ElementList(name = "category", inline = true, required = false)
    public ArrayList<CategoryItem> getSubCategory() {
        return mSubCategoryItems;
    }
}

Now, when I obfuscate the code, if I leave out "-keepattributes Annotation" I get a PersistenceException: Constructor not matched for class.

If I include it, I get an "Unable to determine generic type for parameter 1 of constructor" exception, all these at runtime.
As you can see, the names are there, and I tried to -keep the entire class holding them, all to no avail.

How can I configure Proguard to work with simplexml?

EDIT: My proguard.cfg file is as follows: (it's a bit stuffed with all the things I've tried, but this is the current version)

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-dontpreverify
-verbose
-printseeds
-dontoptimize
-keepattributes *Annotation*
-keepattributes EnclosingMethod

-libraryjars <java.home>/lib/rt.jar (javax/xml/stream/** )

-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

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

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

-dontwarn android.support.**,de.greenrobot.**,org.simpleframework.xml.**
-keep class com.crittercism.**{ *; }
-keepclassmembernames class com.crittercism.**{ *; }
-keepclasseswithmembers class com.crittercism.**{ *; }

-keep class org.simpleframework.**{ *; }
-keepclassmembernames class org.simpleframework.**{ *; }
-keepclasseswithmembers class org.simpleframework.**{ *; }

-keep class crittercism.android.**
-keepclassmembers public class com.crittercism.*{ *;}

-keep public class database.** {
    public static <fields>;
}

-keep class android.support.**
-keepclasseswithmembers class android.support.** { *;}

-keep class org.simpleframeork.**
-keepclasseswithmembers class org.simpleframeork.** { *;}

-keep class javax.**
-keepclasseswithmembers class javax.** { *;}

-keep class com.test.category.**
-keepclassmembernames class com.test.category.** { *; }
-keepclasseswithmembers class com.test.category.** { *;}

-keep class com.test.download.**
-keepclassmembernames class com.test.download.** { *; } 
-keepclasseswithmembers class com.test.download.** { *;}

-keep class org.simpleframework.**{ *; } 
-keep class org.simpleframework.xml.**{ *; } 
-keep class org.simpleframework.xml.core.**{ *; } 
-keep class org.simpleframework.xml.util.**{ *; }
-keep class org.simpleframework.xml.stream.**{ *; }

-keepclassmembers class * implements java.io.Serializable {
    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();
}

Answer

Konstantin Pribluda picture Konstantin Pribluda · Sep 6, 2012

You already figured out that keeping annotation is a good idea. You may also try to add type parameter to @ElementList annotation - apparently there is a problem with generic type erasure and simplexml needs additional hint about type of elements in the list

you may also play around with -keepattributes Signature, *Annotation*:

The "Signature" attribute is required to be able to access generic types when compiling in JDK 5.0 and higher.