Hi,
The question would be, why do you want to do it? I think it might be
possible, but probably nobody has ever tested it. Flink is a distributed
system, so running it on an Android phone doesn't make much sense.
I would suggest you first make your app/example work outside of Android. To
make sure that dependencies and project setup is correct. Keep in mind that
you also need to start somehow a Flink cluster. I would expect that
starting a minicluster with a local execution environment
(StreamExecutionEnvironment.createLocalEnvironment(...) instead of
StreamExecutionEnvironment.getExecutionEnvironment()) would be the way to
go. Unless you want to run a distributed cluster across multiple Android
phones, but in that case I really don't know why you would like to do it :)
Also, Android has its own JDK, which we have never tested. It might cause
some problems.
Piotrek
wt., 2 mar 2021 o 16:23 Alexander Borgschulze <
alexander.borgschu...@stud.uni-regensburg.de> napisał(a):
> I was trying to run Apache Flink within an Android App. I just want to run a
> minimum working example, like this:
>
> @Override
> protected void onCreate(Bundle savedInstanceState) {
> super.onCreate(savedInstanceState);
> setContentView(R.layout.activity_main);
>
> runFlinkExample();
> }
>
> private void runFlinkExample() {
> StreamExecutionEnvironment env =
> StreamExecutionEnvironment.getExecutionEnvironment();
> DataStream<Integer> stream = env.fromCollection(Arrays.asList(1, 2, 3, 4,
> 5));
> stream.print();
> try {
> env.execute();
> } catch (Exception e) {
> e.printStackTrace();
> }
> }
>
>
> These are my two .gradle files:
>
>
> *build.gradle (Module)*
>
>
> plugins {
> id 'com.android.application'
> }
>
> android {
> compileSdkVersion 30
> buildToolsVersion "30.0.3"
>
> defaultConfig {
> applicationId "com.example.flink"
> minSdkVersion 26
> targetSdkVersion 30
> versionCode 1
> versionName "1.0"
>
> testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
> }
>
> buildTypes {
> release {
> minifyEnabled false
> proguardFiles
> getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
> }
> }
> compileOptions {
> sourceCompatibility JavaVersion.VERSION_1_8
> targetCompatibility JavaVersion.VERSION_1_8
> }
>
> packagingOptions {
> exclude 'META-INF/DEPENDENCIES'
> exclude 'reference.conf'
> }
> }
>
> dependencies {
>
> implementation 'androidx.appcompat:appcompat:1.2.0'
> implementation 'com.google.android.material:material:1.3.0'
> implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
> testImplementation 'junit:junit:4.+'
> androidTestImplementation 'androidx.test.ext:junit:1.1.2'
> androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
>
> // Flink
> implementation 'org.apache.flink:flink-streaming-java_2.12:1.12.1'
> implementation 'org.apache.flink:flink-clients_2.12:1.12.1'
> }
>
>
> *build.gradle (Project)*
>
> // Top-level build file where you can add configuration options common to all
> sub-projects/modules.
> buildscript {
> repositories {
> google()
> jcenter()
> }
> dependencies {
> classpath "com.android.tools.build:gradle:4.1.2"
>
> // NOTE: Do not place your application dependencies here; they belong
> // in the individual module build.gradle files
> }
> }
>
> allprojects {
> repositories {
> google()
> jcenter()
> }
> }
>
> task clean(type: Delete) {
> delete rootProject.buildDir
> }
>
>
>
> The first problem is, that I get the following Error:
> Caused by: java.lang.ClassNotFoundException: Didn't find class
> "org.apache.flink.streaming.api.environment.StreamExecutionEnvironment" on
> path: DexPathList[[zip file "/data/app/~~DbT_CZ7AhLED2xZgLBk ....
>
>
>
> In cases there this error doesn't appear, I get Akka-Actor errors, because
> I must exclude 'reference.conf', otherwise the code wouldn't compile.
> However, this leads to more exceptions, e.g. missing akka-version.
>
> So my general question is: Is it possible to run Flink within an
> Android-App? Or is this not possible (recommended)? Perhaps someone knows
> how to modfiy my gradle files (or something else) to run my example. Or
> perhaps someone already has successfully used Flink in Android.
>
