Android JavascriptInterface not working with minifyEnabled

Question

Thanks in advance.

I spend too much time reading stackoverflow about this. I have an hybrid app with a webview and inside a jquery web. I have my javascript interface.

Every think works fine when I run my app in debug mode, but when I run in release mode the javascript interface not working at all.

I try too many solutions like proguard rules:

-keep public class com.mypackage.MyClass$MyJavaScriptInterface
-keep public class * implements com.mypackage.MyClass$MyJavaScriptInterface
-keepclassmembers class com.mypackage.MyClass$MyJavaScriptInterface { 
   <methods>; 
}
-keepattributes JavascriptInterface

I have my notation @JavascriptInterface as you see:

public static class WebAppInterface {
    Context mContext;

WebAppInterface(Context c) {
    mContext = c;
}

@JavascriptInterface
    public void estoyenchat() { enchat=true;
}
....

}

And in my gradle file:

minSdkVersion 14
targetSdkVersion 22

And the only solution I found to run the app with the javascript interface working in release mode is to set minifyEnabled to false.

Someone knows the reason?

Answer 1

Create an interface named JsInterface

public interface JsInterface {}

Implement it in your js interface classes.

public class WebAppInterface implements JsInterface {

Context mContext;

WebAppInterface(Context c) {
    mContext = c;
}

@JavascriptInterface 
public void estoyenchat() { enchat=true;
}

Add to proguard:

-keepclassmembers,allowobfuscation,allowoptimization interface * extends com.mysite.JsInterface{*;}

Answer 2

The correct way to keep any methods that have the @JavascriptInterface annotation would be:

-dontnote android.webkit.JavascriptInterface
-keepclassmembers class * {
    @android.webkit.JavascriptInterface <methods>;
}