How to use pre-trained .model file for predictions in Android Studio?

Question

I have trained a Decision Table ML model in Weka 3.8 Dekstop Version. I have saved the model accordingly in my assets folder and configured the wekaSTRIPPED.jar file as well. At this point, the build seems to be working fine on Android Studio. However, when I try to use the classification model in Java, I am getting some red highlights - errors - over my code which I am unable to autofix.

I have visited some online guides here and visited this commonly used weka-android reference here and here . They follow the same structure as what I have been doing in my code (with different models), but mine does not compile in Android Studio.

package com.example.owner.introductoryapplication;

import android.support.v7.app.AppCompatActivity;

import weka.classifiers.Classifier;
import weka.classifiers.rules.DecisionTable;
import weka.core.Attribute;
import weka.core.DenseInstance;
import weka.core.Instances;

import java.util.ArrayList;

public class Test extends AppCompatActivity {
    public static void main(String[] args) throws Exception {
        Test test = new Test();
        test.start();
    }
    public void start() throws Exception {
        //LOADS THE MODEL...
        String rootPath = "/assets/";
        String fileName = "PGBD_DecisionTableUPD.model";
        //Classifier cls = null;
        Classifier cls = (Classifier) weka.core.SerializationHelper.read(rootPath + fileName);

I expect the output to simply build; I don't expect any prediction output because I haven't specified the testing data-set. However, when I do click compile, none of the terms are highlighted red on the screen.

Specifically, immediately after I run it, I get Compilation failed; see the compiler error output for details. Compilation failed; see the compiler error output for details. in the build console followed by:

"C:\Program Files\Android\Android Studio\jre\bin\java.exe" -Didea.launcher.port=64163 "-Didea.launcher.bin.path=C:\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath "C:\Users\Owner\AppData\Local\Android\Sdk\platforms\android-28\android.jar;C:\Users\Owner\AppData\Local\Android\Sdk\platforms\android-28\data\res;C:\Users\Owner\AndroidStudioProjects\IntroductoryApplication\app\build\intermediates\javac\debug\compileDebugJavaWithJavac\classes;C:\Users\Owner\AndroidStudioProjects\IntroductoryApplication\app\build\generated\res\rs\debug;C:\Users\Owner\AndroidStudioProjects\IntroductoryApplication\app\build\generated\res\resValues\debug;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\customview-28.0.0.aar\14e09720fc7f657365dec6e786490d47\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\localbroadcastmanager-28.0.0.aar\d791f241c61f09475b5d43561b131f77\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-vector-drawable-28.0.0.aar\c8f91860fd6811b7040ad585c1bb749f\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\interpolator-28.0.0.aar\73289dbc6711e8292415efe83a859a43\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-core-utils-28.0.0.aar\2dc7d30dd7abd1c4b0846462e1137cc4\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-core-ui-28.0.0.aar\b5199754cf7a7bf403b3073b69edcfe3\jars\classes.jar;C:\Users\Owner\AndroidStudioProjects\IntroductoryApplication\app\libs\wekaSTRIPPED.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\slidingpanelayout-28.0.0.aar\32aa91f4149120a8a428b24c5291b432\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\viewmodel-1.1.1.aar\3477f32913f9b9934a8185f031c05533\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\drawerlayout-28.0.0.aar\bfb4eb97f205f1db9a43db5a200619a5\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\coordinatorlayout-28.0.0.aar\aba273524bbeff5bfab162bc52fb07b9\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\coordinatorlayout-28.0.0.aar\aba273524bbeff5bfab162bc52fb07b9\res;C:\Users\Owner\.gradle\caches\modules-2\files-2.1\com.android.support\collections\28.0.0\c1bcdade4d3cc2836130424a3f3e4182c666a745\collections-28.0.0.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\documentfile-28.0.0.aar\e49f57095504cc48cc7ba2b26757daf1\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\constraint-layout-1.1.3.aar\96728e03169a340c5e642682fbd18ff8\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\constraint-layout-1.1.3.aar\96728e03169a340c5e642682fbd18ff8\res;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\swiperefreshlayout-28.0.0.aar\a560a21fcde6d062081d9c09634c92a8\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\cursoradapter-28.0.0.aar\733ca7f2a61e46bdb2164e238fe8c4b6\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\asynclayoutinflater-28.0.0.aar\f950d05bc8679714fb0d7642259e29eb\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\livedata-1.1.1.aar\400a5420ad5e4bcef8ebbebf2123e101\jars\classes.jar;C:\Users\Owner\.gradle\caches\modules-2\files-2.1\android.arch.core\common\1.1.1\e55b70d1f5620db124b3e85a7f4bdc7bd48d9f95\common-1.1.1.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\versionedparcelable-28.0.0.aar\12c3dd068050bf0422d8455749982d52\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\runtime-1.1.1.aar\68e9f88e3e623f899ee79dd4aa8966f1\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\print-28.0.0.aar\f12fdac753fb8cbf34b55eced23a29c7\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\loader-28.0.0.aar\0f1fa1caaba4127fdcb1d7bb76f1c144\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\viewpager-28.0.0.aar\bdf7976216feddc6d17d8052bf1807db\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-fragment-28.0.0.aar\df9931f8c3d84779819dccebe1aa6282\jars\classes.jar;C:\Users\Owner\.gradle\caches\modules-2\files-2.1\com.android.support\support-annotations\28.0.0\ed73f5337a002d1fd24339d5fb08c2c9d9ca60d8\support-annotations-28.0.0.jar;C:\Users\Owner\.gradle\caches\modules-2\files-2.1\android.arch.lifecycle\common\1.1.1\207a6efae6a3555e326de41f76bdadd9a239cbce\common-1.1.1.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\livedata-core-1.1.1.aar\f5b8b9e2bbbf6e16caa00d091d538f2f\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-compat-28.0.0.aar\0fefdb1435b453663f8b867197d75a41\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\support-compat-28.0.0.aar\0fefdb1435b453663f8b867197d75a41\res;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\animated-vector-drawable-28.0.0.aar\7eca742b05d3ca93c5f22855deb68690\jars\classes.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\appcompat-v7-28.0.0.aar\b5690672012030cd411a187af3fc56e5\res;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\appcompat-v7-28.0.0.aar\b5690672012030cd411a187af3fc56e5\jars\classes.jar;C:\Users\Owner\.gradle\caches\modules-2\files-2.1\com.android.support.constraint\constraint-layout-solver\1.1.3\bde0667d7414c16ed62d3cfe993cff7f9d732373\constraint-layout-solver-1.1.3.jar;C:\Users\Owner\.gradle\caches\transforms-1\files-1.1\runtime-1.1.1.aar\b33f18eb28c72c82424fc1a72a917596\jars\classes.jar;C:\Program Files\Android\Android Studio\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMainV2 com.example.owner.introductoryapplication.Test
Exception in thread "main" java.lang.RuntimeException: Stub!
    at android.content.Context.<init>(Context.java:67)
    at android.content.ContextWrapper.<init>(ContextWrapper.java:30)
    at android.view.ContextThemeWrapper.<init>(ContextThemeWrapper.java:40)
    at android.app.Activity.<init>(Activity.java:643)
    at android.support.v4.app.SupportActivity.<init>(ComponentActivity.java:46)
    at android.support.v4.app.FragmentActivity.<init>(FragmentActivity.java:68)
    at android.support.v7.app.AppCompatActivity.<init>(AppCompatActivity.java:62)
    at com.example.owner.introductoryapplication.Test.<init>(Test.java:13)
    at com.example.owner.introductoryapplication.Test.main(Test.java:15)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131)

Process finished with exit code 1

Though, from what I understand, I have already included the .model file in my assets folder; it should recognize the file path.

Answer 1

Use .open("PGBD_DecisionTable.model") instead of .open(PGBD_DecisionTable.model) .

You are trying to load a file from a constant String expression, not a static property of a class named PGBD_DecisionTable .