ClassNotFoundException: Didn't find class "com.chaquo.python.PyException"

[mhsmith]

Originally posted by @tongjinlv in #43 (comment)

I compiled into release but is run error
error message：
lang.ClassNotFoundException: Didn't find class "com.chaquo.python.PyException" on path: DexPathList[[zip file "/data/app/com.matatalab.matatacode-9_fj_Bw-RN1FBE6tu42f0A==/base.apk"],nativeLibraryDirectories=[/data/app/com.matatalab.matatacode-9_fj_Bw-RN1FBE6tu42f0A==/lib/arm64, /data/app/com.matatalab.matatacode-9_fj_Bw-RN1FBE6tu42f0A==/base.apk!/lib/arm64-v8a, /system/lib64, /product/lib64]]

[mhsmith]

Please post the full stack trace, and any relevant source code.

[tongjinlv]

The problem is solved due to the release mode compression, thank you very much

[mhsmith]

Originally posted by @zeynabimani in #358 (comment)

Hi. I have almost the same problem. I just want to start Python in my android application, but when I use this code I get an error.
The code is:

if (!Python.isStarted()) { Python.start(new AndroidPlatform(this)); }

When I use this code in any part of the program MainActivity or somewhere else I got the error and I don't know why?!

The error is:

2020-08-19 18:19:04.135 12263-12263/com.dji.sdk.sample E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.dji.sdk.sample, PID: 12263
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.dji.sdk.sample/com.dji.sdk.sample.internal.controller.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.chaquo.python.PyException" on path: DexPathList[[zip file "/system/framework/org.apache.http.legacy.boot.jar", zip file "/data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/base.apk", dex file "InMemoryDexFile[cookie=[0, 494810873152]]", dex file "InMemoryDexFile[cookie=[0, 494810874496]]"],nativeLibraryDirectories=[/data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/lib/arm64, /data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/base.apk!/lib/arm64-v8a, /system/lib64]]
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2977)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3114)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:113)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:71)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1859)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:201)
        at android.app.ActivityThread.main(ActivityThread.java:6831)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:927)
     Caused by: java.lang.ClassNotFoundException: Didn't find class "com.chaquo.python.PyException" on path: DexPathList[[zip file "/system/framework/org.apache.http.legacy.boot.jar", zip file "/data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/base.apk", dex file "InMemoryDexFile[cookie=[0, 494810873152]]", dex file "InMemoryDexFile[cookie=[0, 494810874496]]"],nativeLibraryDirectories=[/data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/lib/arm64, /data/app/com.dji.sdk.sample-ImLlWv7TGO-MqNuoILbVIA==/base.apk!/lib/arm64-v8a, /system/lib64]]
        at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:171)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:379)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:312)
        at com.chaquo.python.Python.startNative(Native Method)
        at com.chaquo.python.Python.a(:50)
        at com.dji.sdk.sample.internal.controller.MainActivity.onCreate(:113)
        at android.app.Activity.performCreate(Activity.java:7224)
        at android.app.Activity.performCreate(Activity.java:7213)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2957)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3114) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:113) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:71) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1859) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:201) 
        at android.app.ActivityThread.main(ActivityThread.java:6831) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:927) 

I read the documentation, and I know one way for starting python is to change the application name in androidManifest.xml file, but I can't do this because I use a Sample Application, and I can't change the application name in the manifest file.

Can you please help me find the problem?

[mhsmith]

The problem is solved due to the release mode compression, thank you very much

@tongjinlv: can you explain what you mean by this? For example, was it affected by the build variant? What exactly did you do to solve it?

[mhsmith]

@zeynabimani: Changing the application name in the AndroidManifest.xml shouldn't be necessary, because they only thing PyApplication does is make that same Python.start call.

Which devices or emulators have you tried running the app on, and did they all show the same problem?

[mhsmith]

OK, I think I've found the cause. Try editing your build.gradle file to change every appearance of minifyEnabled true to minifyEnabled false.

This will be fixed in the next version of Chaquopy.

[zeynabimani]

Thank you very much @mhsmith.
My problem solved by changing minifyEnabled true to minifyEnabled false.

[mhsmith]

This issue is fixed in Chaquopy 9.0.0. To upgrade, edit your app's top-level build.gradle file and change the version number of com.chaquo.python:gradle.