/android_async_lib

Wery small Kotlin library for asynchronous task execution on Android

Primary LanguageKotlinApache License 2.0Apache-2.0

A small Kotlin library for asynchronous task on Android

The library for Kotlin provide functions for easy execution of tasks in thread use lambda style, and send lambda for update UI (like runOnUiThread in Android) the library is currently under testing

Version:

0.4.3b current

dependencies update

0.3.3b current

improvements usage from Java

0.2.2b

dependencies fix

0.2.1b

provider return real classes

0.2.0b

Add LifeCycle support

Add HandlerThread Executor

0.1.0b

first version

Installation:

1 in project level build.gradle add:


allprojects {
repositories {
........
        maven { url "https://jitpack.io" }
        }
   }

or in setting.gradle add:

dependencyResolutionManagement {
    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
    repositories {
    ......
    maven { url 'https://jitpack.io' }
    }
}

2 in module level build.gradle add:

dependencies {
...........
         implementation 'com.github.DmitryStarkin:android_async_lib:version'
   }

Usage:

If you need to execute code asynchronously, just use one of the functions provided by the library.
You can pass a callback to the function to process the result and to handle the error.
Operations are performed using an executor that is passed as the first parameter.
The library contains a Class that provides implementations of Executor:

globalSingleTreadPoll - operations are performed on a ThreadPool with a single thread that exists in a single instance within the application process.

globalMultiThreadPoll - operations are performed on a ThreadPool with a starting number of threads equal to the number of processors + 1
and a maximum number of threads equal to the number of processors * 2. this pool exists in a single instance within the application process.

newSingleThreadPoll() - the same as globalSingleTreadPoll but return new instance each time

newMultiThreadPoll() - the same as globalMultiThreadPoll but return new instance each time

newThread() - a new Thread is created for execution each time

newHandlerThread() - a new HandlerThread is created for execution each time

currentThread() - task is performed in the calling thread

mainThread() - task is performed in the main thread

Executors, in addition to global ones, can be linked to the Lifecycle of an Activity or Fragment using the connectToLifecycle(owner: LifecycleOwner) method

There are extensions for LifecycleOwner that do this automatically

You can use your own implementation of the Executor (see ThreadPoolExecutor for example)
or get it using Java factory Executors See Executors

For convenience the library includes extension functions for the Executor interface

Regardless of where the task is executed callbacks are always executed in the main thread

See Docs

Kotlin code example

class SomeClass : AppCompatActivity() {

    private val textView: TextView = TextView(this) //for example
    var thread: Thread? = null
    private val executor =
        this.getHandlerThread() //HandlerThread executor associated with the lifecycle of this activity

    private val executor2 =
        newHandlerThread().apply { connectToLifecycle(this@SomeClass) } //do the same

    fun someFun() {
        val inputStream: InputStream = File("example.txt").inputStream()
        //start operation on new Thread
        thread = inputStream.runOnThread(
            { text -> textView.text = text },// callback on main thread
            { e -> textView.text = e.toString() })// callback on main thread
        {
            bufferedReader().use { it.readText() }// execute on new thread
        }
    }

    fun someFun1() {

        val file = File("example.txt")
        thread = file.processingOnThread(
            { text -> textView.text = text }, // callback on main thread
            { e -> textView.text = e.toString() })// callback on main thread
        { _file ->
            _file.inputStream().bufferedReader().use { it.readText() }// execute on new thread
        }
    }

    fun someFun2() {

        val file = File("example.txt")
        thread = handleOnThread(
            file,
            { text -> textView.text = text }, // callback on main thread
            { e -> textView.text = e.toString() }) // callback on main thread
        {
            it.inputStream().bufferedReader()
                .use { reader -> reader.readText() }// execute on new thread, it represent parameter file
        }
    }


    fun someFun3() {

        val file = File("example.txt")
        //start operation on given Executor
        runOnExecutor(
            globalSingleTreadPoll,
            { text -> textView.text = text }, // callback on main thread
            { e -> textView.text = e.toString() }) // callback on main thread
        {
            file.inputStream().bufferedReader()
                .use { it.readText() }// execute on threadPool, file captured in closure
        }
    }

    fun someFun4() {

        val file = File("example.txt")
        //start operation on given Executor
        file.runOnExecutor(
            globalSingleTreadPoll,
            { text -> textView.text = text }) // callback on main thread
        // stub error wil be use (just throws error)
        { inputStream().bufferedReader().use { it.readText() } }// execute on threadPool
    }

    fun someFun5() {
        // does the same as the previous function but uses a pre installed thread pool
        val file = File("example.txt")
        file.runOnGlobalSinglePool({ text -> textView.text = text }) // callback on main thread
        // stub error wil be use (just throws error)
        {
            inputStream().bufferedReader().use { it.readText() } // execute on threadPool
        }
    }

    fun someFun6() {
        // print new value in textView every 1 second 100 times
        runOnGlobalSinglePool { // start task on single threadPoll use stub as result and error callbacks
            for (i in 0..100) {
                Thread.sleep(1000)
                runOnUI { textView.text = i.toString() } // execute lambda on UI thread
            }
        }
    }

    fun someFun7() {

        val file = File("example.txt")
        //start operation on on HandlerThread
        executor.launch(
            { text -> textView.text = text }, // callback on main thread
            { e -> textView.text = e.toString() }) // callback on main thread
        {
            file.inputStream().bufferedReader()
                .use { it.readText() } // execute on threadPool, file captured in closure
        }
    }

    fun someFun8() {
        // print new value in textView every 1 second 100 times
        executor2.launch { // start task on HandlerThread use stub as result and error callbacks
            for (i in 0..100) {
                Thread.sleep(1000)
                runOnUI { textView.text = i.toString() } // execute lambda on UI thread
            }
        }
    }

    override fun onDestroy() {
        super.onDestroy()
        //executor.quit() this call is not needed here because the executor is associated with the lifecycle
        //executor2.quit() this call is not needed here because the executor2 is associated with the lifecycle
        globalSingleTreadPoll.purge() //clearing the task queue
        thread?.interrupt()
    }
}

Java code example

class TestClass extends AppCompatActivity {


    private TextView textField = new TextView(this); //for example
    Thread thread = null;
    //HandlerThread executor associated with the lifecycle of this activity
    HandlerThreadExecutor executor = LifeCycleExecutors.getHandlerThread(this);
    HandlerThreadExecutor executor2 = ExecutorsProvider.newHandlerThread();


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        executor2.connectToLifecycle(this);
    }

    void someFun() throws FileNotFoundException {
        File file = new File("example.txt");
        //start operation on new Thread
        thread = ThreadUtil.runOnThread(file,
                s -> {
                    textField.setText(s);
                    return Unit.INSTANCE;
                },// callback on main thread in Java code must return Unit.INSTANCE or null :(
                e -> {
                    textField.setText(e.toString());
                    return null;
                }, // callback on main thread in Java code must return Unit.INSTANCE or null :(
                f -> {
                    BufferedReader reader = null;
                    String text = null;
                    try {
                        try {
                            reader = new BufferedReader(new FileReader(f));
                            text = reader.readLine();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    } finally {
                        try {
                            reader.close();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                    return text;
                }); // execute on new thread, we must handle some Exception in Java
    }

    void someFun1() {
        // print new value in textView every 1 second 100 times
        AsyncOperation.launch(executor2, u -> { //The function has the unit type that is passed so we must explicitly specify the parameter
            for (int i = 0; i < 100; i++) {
                int finalI = i;
                UiUtil.runInUI(() -> {
                    textField.setText(finalI);
                    return null; // callback on main thread in Java code must return Unit.INSTANCE or null :(
                });
            }
            return null; // lambda on main thread in Java code must return Unit.INSTANCE or null :(
        });
    }
    
    void someFun2() {
        // print new value in textView every 1 second 100 times. 
        AsyncOperation.runOnGlobalMultiPool(u -> { //The function has the unit type that is passed so we must explicitly specify the parameter
            for (int i = 0; i < 100; i++) {
                int finalI = i;
                UiUtil.runInUI(() -> {
                    textField.setText(finalI);
                    return null; // callback on main thread in Java code must return Unit.INSTANCE or null :(
                });
            }
            return null; // lambda on main thread in Java code must return Unit.INSTANCE or null :(
        });
    }
    @Override
    protected void onDestroy() {
        super.onDestroy();
        //executor.quit() this call is not needed here because the executor is associated with the lifecycle
        //executor2.quit() this call is not needed here because the executor2 is associated with the lifecycle
        ExecutorsProvider.getGlobalSingleTreadPoll().purge(); //clearing the task queue
        thread.interrupt();
    }
}