Unity Error: Unable to convert classes to dex format

Question

I created an Android Unity plugin (.aar file) that provides some custom positioning data for my Unity game. In my Unity script, I use

var x = customClass.CallStatic<float>("getHeadX");

To get location data. This method is called for each frame to obtain updated data (polling method), which makes it inefficient. Instead, I decided to call the C # method in my Unity script from my java code (plugin) when the updated data is ready. For this, in my java plugin I wrote

import com.unity3d.player.UnityPlayer;
...
UnityPlayer.UnitySendMessage("Manager", // gameObject name
                             "PluginCallback", // this is a callback in C# 
                             "Hello from android plugin"); // msg which is not needed actually

However, the compiler complained that the com.unity3d.player.UnityPlayer package did not exist. So I copied the classes.jar file from

C: \ Program Files (X86) \ Unity \ Editor \ Data \ PlaybackEngines \ AndroidPlayer \ Variations \ mono \ Release \ Classes \ classes.jar

to the "libs" folder of my Android plugin project. I built it successfully and copied the generated .aar file (mylibrary-release.aar) to the Assets \ Plugins \ Android folder of my Unity project.

When I create a Unity project (using the "internal" build system), it gives me this error:

IOException: Failed to move the file / directory from 'Temp / StagingArea \ android-libraries \ mylibrary-release \ classes.jar' to 'Temp / StagingArea \ android library \ MyLibrary release \ LIES \ classes.jar . UnityEditor.Android.PostProcessor.Tasks.ProcessAAR.Execute ...

- , classes.jar classes.jar(- ). unity_classes.jar, , :

CommandInvokationFailure: dex.C:/Program Files/Java/jdk1.8.0_102\bin\java.exe -Xmx2048M Dcom.android.sdkmanager.toolsdir = "C: \/Users/kamran.shamloo/AppData/Local/Android/Sdk " -Dfile.encoding = UTF8 -jar "C:\Program Files (x86)\Unity\Editor\Data\PlaybackEngines\AndroidPlayer/Tools\sdktools.jar"

stderr [ : java.lang.IllegalArgumentException: : Lbitter/jnibridge/JNIBridge; : java.lang.IllegalArgumentException: : Lbitter/jnibridge/JNIBridge $; : java.lang.IllegalArgumentException: : Lcom/Unity3D//NativeLoader; : java.lang.IllegalArgumentException: : Lcom/Unity3D//ReflectionHelper; : java.lang.IllegalArgumentException: : Lcom/Unity3D//ReflectionHelper $1; : java.lang.IllegalArgumentException: : Lcom/Unity3D//ReflectionHelper $; : java.lang.IllegalArgumentException: : Lcom/Unity3D//UnityPlayer; : java.lang.IllegalArgumentException: : Lcom/Unity3D//UnityPlayer $1; : java.lang.IllegalArgumentException: : Lcom/Unity3D//UnityPlayer $10;...

Answer 1

.jar( "unity_classes.jar" ) .apk Unity, ( Android-), .

, Android .jar . , Unity , .jar( Android). , Unity , 2 .jar , : " dex".

, ( .jar) , . ? Android, , .jar .

:

1) 'build.gradle' :

compile files('libs/jars/unity_classes.jar')

:

provided files('libs/jars/unity_classes.jar')

2) ( Android) . . Unity ( single_classes.jar) .