0. 簡介 Service

Service 不一定用得很長久，那不就成了長傭了嗎？我們可以用 JobIntentService ——臨時傭人，它跟你的 App 同生共死，真好！但是，啟動容易，關閉就毫無頭緒了，因為 Service 在后臺跑，跟 UI 是不沾邊的，如果用 MVVM，我們可以塞 LiveData ，通過方程啟動，系統會彈出 “LiveData has not initialed”，如果用 Service 的建構式，系統會說不接受引數，饒頭啊，對不？

沒關系，我們可以使用插入式，我提議的是 Dagger-Hilt ，給系統打針，

📦 1. MVVM 包

🌮 Gradle —— 資料庫選擇：

View Binding：

buildFeatures {
    viewBinding true
}

Dagger Hilt ——請自學安裝，
ViewModel：

//region activity and fragment
// Activity and Fragment
def activity_version = "1.2.1"
implementation "androidx.activity:activity-ktx:$activity_version"
def fragment_version = "1.3.2"
implementation "androidx.fragment:fragment-ktx:$fragment_version"
debugImplementation "androidx.fragment:fragment-testing:$fragment_version"
//endregion

這里隨便提提，其實你們可以抄我以前寫的，Gradle 太占地方了，所以省略一二，
…

🔰 MVVM —— 檔案排列

在這里插入圖片描述

🖐🏻 Helper —— 幫手

helper/LogHelper.kt

import android.util.Log

const val TAG = "MLOG"
fun lgd(s:String) = Log.d(TAG, s)
fun lgi(s:String) = Log.i(TAG, s)
fun lge(s:String) = Log.e(TAG, s)
fun lgv(s:String) = Log.v(TAG, s)
fun lgw(s:String) = Log.w(TAG, s)

helper/MessageHelper.kt

import android.content.Context
import android.widget.Toast
import android.widget.Toast.LENGTH_LONG
import android.widget.Toast.LENGTH_SHORT

fun msg(context: Context, s: String, len: Int) =
    if (len > 0) Toast.makeText(context, s, LENGTH_LONG).show()
    else Toast.makeText(context, s, LENGTH_SHORT).show()

🖌? 2. UI Design 平面設計

et_message ：輸入資料進Service，
tv_service ：Service 的反應，

💼 3. JobIntentService

JobIntentService 是 IntentService 的改良版，

🐔 開始服務

這個服務是用方程啟動的——enqueueWork

fun enqueueWork(context: Context, work: Intent) {
    enqueueWork(context, MyIntentService::class.java, JOB_ID, work)
}

這個 enqueueWork 有 4 種引數：

Context
Service class
Job ID
Intent

?? 關閉服務

用 instance 關閉，

class MyIntentService: JobIntentService() {

    init {
        instance = this
    }
    
	companion object {
		private lateinit var instance: MyIntentService
		private val JOB_ID = 4343443

		fun enqueueWork(context: Context, work: Intent) {...}

		fun stopService() {
			lgd("MyIntentService: Service is stopping...")
			instance.stopSelf()
		}
	}
}

你瞧，自己關自己，

🚪 4. Permission

📍 AndroidManifest.xml

<uses-permission android:name="android.permission.WAKE_LOCK" />
<application
    ...
    <activity android:name=".ui.MainActivity">
        ...
    </activity>
    <service android:name=".service.MyIntentService"
        android:permission="android.permission.BIND_JOB_SERVICE"
        android:exported="true" />
</application>

…

?? ui/MainActivity.kt

// check manifests for permissions
private val REQUIRED_PERMISSIONS = arrayOf(
    Manifest.permission.WAKE_LOCK
)

class MainActivity : AppCompatActivity() {

    // app permission
    private val reqMultiplePermissions = registerForActivityResult(
        ActivityResultContracts.RequestMultiplePermissions()
    ) { permissions ->
        permissions.entries.forEach {
            lgd("mainAct: Permission: ${it.key} = ${it.value}")
            if (!it.value) {
                // toast
                msg(this, "Permission: ${it.key} denied!", 1)
                finish()
            }
        }
    }

    // =============== Variables
    // view binding
    private lateinit var binding: ActivityMainBinding
    // view model
    val viewModel: MainViewModel by viewModels()

    // =============== END of Variables

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        // check app permissions
        reqMultiplePermissions.launch(REQUIRED_PERMISSIONS)
    }

    companion object {
        const val USER_INPUT = "USER_INPUT"
    }
}

?5. Observables & Hilt 觀察和打針

👁?🗨 觀察點

我需要提供兩個觀察點：

isRunning：服務狀態，
userInput：客戶輸入的內容，有兩種方式 IntentExtra 和 LiveData ，我將會測驗那種有保證，

🔆 app/ServiceApp.kt 提供 Hilt 應用

@HiltAndroidApp
class ServiceApp: Application()

…

🗡 di/LiveDataModule.kt

@Module
@InstallIn(SingletonComponent::class)
object LiveDataModule {

    @Provides
    @Singleton
    fun provideServiceStatus(): 
        MutableLiveData<Boolean> = MutableLiveData<Boolean>()

    @Provides
    @Singleton
    fun provideUserInput(): 
        MutableLiveData<String> = MutableLiveData<String>()
    
}

簡單吧，就伺候這倆，
…

?? ui/MainViewModel.kt

@HiltViewModel
class MainViewModel @Inject constructor(
    val isRunning: MutableLiveData<Boolean>,
    private val userInput: MutableLiveData<String>
): ViewModel() {

    init {
        isRunning.value = false
        userInput.value = ""
    }

    fun enableService() {
        isRunning.postValue(true)
    }

    fun updateUserInput(inputText: String) {
        userInput.postValue(inputText)
    }
}

主要功能是更新畫面，

…

🔧 service/MyIntentService.kt

@AndroidEntryPoint
class MyIntentService: JobIntentService() {

    @Inject
    lateinit var isRunning: MutableLiveData<Boolean>

    @Inject
    lateinit var userInput: MutableLiveData<String>

    init {
        instance = this
    }

    override fun onHandleWork(intent: Intent) {
        lgd("onHandleWork")
        try {
            lgd("MyIntentService: Service is running...")
            if (isRunning.value!!) {

                // check Intent Extra
                val extraInput = intent.getStringExtra(USER_INPUT)
                lgd("Intent Extra: $extraInput")
                
                var input = "Empty"
                if (userInput.value != "")
                    input = userInput.value.toString()

                lgd("receive text from LiveData: $input")

                for (i in 0..9) {
                    lgd("Input: $input - $i")
                    if (isRunning.value == false)
                        return
                    SystemClock.sleep(1000)
                }
                stopService()
            }
        } catch (e: InterruptedException) {
            Thread.currentThread().interrupt()
        }
    }
...

…

🔨 ui/MainActivity.kt

@AndroidEntryPoint
class MainActivity : AppCompatActivity() {
    ...

    override fun onCreate(savedInstanceState: Bundle?) {
        ...

        binding.btStart.setOnClickListener {
            viewModel.enableService()

            // update user input
            val inputText = binding.etMessage.text
            if (!inputText.isEmpty() || !inputText.isBlank())
                viewModel.updateUserInput(inputText.toString())
            lgd("input text: $inputText")

            val mIntent = Intent(this, MyIntentService::class.java)
            mIntent.putExtra(USER_INPUT, inputText)

            // start service
            MyIntentService.enqueueWork(this, mIntent)
        }

        binding.btStop.setOnClickListener {
            MyIntentService.stopService()

        }

        // observer
        viewModel.isRunning.observe(this, {
            if (it)
                binding.tvService.text = "Service is Start..."
            else
                binding.tvService.text = "Service is Stop!"
        })
    }

    companion object {...}
}

按鍵提供打開服務，關閉服務，
還有就是觀察服務狀態，

🏃🏻 6. 運行結果

startStop
狀態良好，看看 Logcat：

--------- beginning of system
2021-04-24 14:39:27.113 6199-7154 D/MLOG: onHandleWork
2021-04-24 14:39:27.113 6199-7154 D/MLOG: MyIntentService: Service is running...
2021-04-24 14:39:27.123 6199-7154 D/MLOG: Intent Extra: null
2021-04-24 14:39:27.123 6199-7154 D/MLOG: receive text from LiveData: Empty
2021-04-24 14:39:27.123 6199-7154 D/MLOG: Input: Empty - 0
2021-04-24 14:39:28.164 6199-7154 D/MLOG: Input: Empty - 1
2021-04-24 14:39:29.205 6199-7154 D/MLOG: Input: Empty - 2
2021-04-24 14:39:30.246 6199-7154 D/MLOG: Input: Empty - 3
2021-04-24 14:39:31.273 6199-7154 D/MLOG: Input: Empty - 4
2021-04-24 14:39:32.318 6199-7154 D/MLOG: Input: Empty - 5
2021-04-24 14:39:33.360 6199-7154 D/MLOG: Input: Empty - 6
2021-04-24 14:39:34.375 6199-7154 D/MLOG: Input: Empty - 7
2021-04-24 14:39:35.380 6199-7154 D/MLOG: Input: Empty - 8
2021-04-24 14:39:36.384 6199-7154 D/MLOG: Input: Empty - 9
2021-04-24 14:39:37.387 6199-7154 D/MLOG: MyIntentService: Service is stopping...

加入 Welcome，看看 Service 是否收到，
welcome
Logcat：

2021-04-24 14:44:55.110 6199-6199 D/MLOG: input text: Welcome
2021-04-24 14:44:55.126 6199-7154 D/MLOG: onHandleWork
2021-04-24 14:44:55.126 6199-7154 D/MLOG: MyIntentService: Service is running...
2021-04-24 14:44:55.127 6199-7154 D/MLOG: Intent Extra: null
2021-04-24 14:44:55.127 6199-7154 D/MLOG: receive text from LiveData: Welcome
2021-04-24 14:44:55.127 6199-7154 D/MLOG: Input: Welcome - 0
2021-04-24 14:44:56.168 6199-7154 D/MLOG: Input: Welcome - 1
2021-04-24 14:44:57.211 6199-7154 D/MLOG: Input: Welcome - 2
2021-04-24 14:44:58.251 6199-7154 D/MLOG: Input: Welcome - 3
2021-04-24 14:44:59.293 6199-7154 D/MLOG: Input: Welcome - 4
2021-04-24 14:45:00.334 6199-7154 D/MLOG: Input: Welcome - 5
2021-04-24 14:45:01.377 6199-7154 D/MLOG: Input: Welcome - 6
2021-04-24 14:45:02.418 6199-7154 D/MLOG: Input: Welcome - 7
2021-04-24 14:45:03.460 6199-7154 D/MLOG: Input: Welcome - 8
2021-04-24 14:45:04.501 6199-7154 D/MLOG: Input: Welcome - 9
2021-04-24 14:45:05.542 6199-7154 D/MLOG: MyIntentService: Service is stopping...

IntentExtra 接收失敗，
LiveData 成功，

? 7. Espresso 測驗

? 加測驗

右鍵點擊 “class MyIntentService”，然后 Alt+Insert ，
test
選 Junit4:
junit4
androidTest 檔案夾：

🔭 service/MyIntentServiceTest.kt

@ExperimentalCoroutinesApi
@LargeTest
@HiltAndroidTest
class MyIntentServiceTest {

    @get:Rule(order = 1)
    var hiltRule = HiltAndroidRule(this)

    @get:Rule(order = 2)
    var activityRule = ActivityScenarioRule(MainActivity::class.java)


    @Before
    fun setup() {
        hiltRule.inject()
    }

🍬 helper/Constants.kt —— 常數

const val START = "Service is Start..."
const val STOP = "Service is Stop!"

…

? Stop Test Case —— 停止測驗

@Test
fun test_stop_service_espresso() {
    lgd("=====>  Stop Service Test")

    // start activity
    val scenario = activityRule.getScenario()

    onView(withId(R.id.bt_start)).perform(click())
    lgd("=====>  Start Button Clicked")

    onView(withId(R.id.bt_stop)).perform(click())
    lgd("=====>  Stop Button Clicked")

    val serviceMsg = onView(withId(R.id.tv_service))
    serviceMsg.check(ViewAssertions.matches(
        ViewMatchers.withText(STOP)))
}

好像很正常，讓我們看看 Logcat :

2021-04-27 07:57:31.223 20493-20703 D/MLOG: MyIntentService: Service is running...
2021-04-27 07:57:31.230 20493-20703 D/MLOG: Intent Extra: null
2021-04-27 07:57:31.230 20493-20703 D/MLOG: receive text from LiveData: Empty
2021-04-27 07:57:31.230 20493-20703 D/MLOG: Input: Empty - 0
2021-04-27 07:57:32.278 20493-20703 D/MLOG: Input: Empty - 1
2021-04-27 07:57:33.313 20493-20703 D/MLOG: Input: Empty - 2
2021-04-27 07:57:34.345 20493-20703 D/MLOG: Input: Empty - 3
2021-04-27 07:57:35.356 20493-20703 D/MLOG: Input: Empty - 4
2021-04-27 07:57:36.393 20493-20703 D/MLOG: Input: Empty - 5
2021-04-27 07:57:37.434 20493-20703 D/MLOG: Input: Empty - 6
2021-04-27 07:57:38.473 20493-20703 D/MLOG: Input: Empty - 7
2021-04-27 07:57:39.475 20493-20703 D/MLOG: Input: Empty - 8
2021-04-27 07:57:40.521 20493-20703 D/MLOG: Input: Empty - 9
2021-04-27 07:57:41.558 20493-20703 D/MLOG: MyIntentService: Service is stopping...
2021-04-27 07:57:41.792 20493-20533 D/MLOG: =====>  Start Button Clicked
2021-04-27 07:57:41.850 20493-20493 D/MLOG: MainAct: stop button clicked!
2021-04-27 07:57:41.850 20493-20493 D/MLOG: MyIntentService: Service is stopping...
2021-04-27 07:57:42.089 20493-20533 D/MLOG: =====>  Stop Button Clicked

糟透了，Espresso 在 Service 停止后才出來干活，因此，我們需要另一種工具來測驗 —— UiAutomator ，

🚍 8. UiAutomator

📌 gradle.module

//UiAutomator
androidTestImplementation 'androidx.test.uiautomator:uiautomator:2.2.0'

Sync，

…

📢 MyIntentJobServiceTest

@get:Rule(order = 1)
var hiltRule = HiltAndroidRule(this)

這個保留，

private var mDevice: UiDevice? = null

啟動：

@Before
fun setup() {
    hiltRule.inject()

    // Initialize UiDevice instance
    mDevice = UiDevice.getInstance(getInstrumentation())
    mDevice!!.pressMenu()
    val launcherPackage = mDevice!!.launcherPackageName
    Truth.assertThat(launcherPackage).isNotNull()

    mDevice!!.wait(
        Until.hasObject(By.pkg(launcherPackage).depth(0)),
        LAUNCH_TIMEOUT
    )

    // launch app
    val context = ApplicationProvider.getApplicationContext<Context>()
    val intent = context.packageManager.getLaunchIntentForPackage(
        APPLICATION_ID)?.apply {
        // Clear out any previous instances
        addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK)
    }
    context.startActivity(intent)

    // Wait for the app to appear
    mDevice!!.wait(
        Until.hasObject(By.pkg(APPLICATION_ID).depth(0)),
        LAUNCH_TIMEOUT
    )
}
companion object {
    const val LAUNCH_TIMEOUT = 5000L
}

加 Test ：

@Test
fun test_stop_service_uiautomator() {
}

🔍 用 ID 找物體

UiAutomator 找東西跟安卓是一樣的：

val $var$ = mDevice!!.findObject(
    res("${APPLICATION_ID}:id/$obj$"))

這是 Live Template 捷徑，

讓我們加兩個按鍵：

// buttons
val startBt = mDevice!!.findObject(
    res("${APPLICATION_ID}:id/bt_start"))
val stopBt = mDevice!!.findObject(
    res("${APPLICATION_ID}:id/bt_stop"))

同樣程序再試試：啟動服務 → 停止服務 → 檢查

lgd("start bt: ${startBt.resourceName}")
startBt.click()

Thread.sleep(1000L)

lgd("stop bt: ${stopBt.resourceName}")
stopBt.click()

// service message
val serviceMsg = mDevice!!.findObject(
    res("${APPLICATION_ID}:id/tv_service"))
val statusStr = serviceMsg.text
Truth.assertThat(statusStr).isEqualTo(STOP)

🚴跑啊：
test2
這次，你應該看到測驗沒有用到 10 秒，幾乎立刻就停止了，所以這是成功的測驗，

🚁 9. UiAutomator — UserInput 輸入測驗

👁?🗨 LogOutput.kt —— Log 輸出

我們可以截取一部分 Log 來檢查成果，

/**
 *  Editor: Homan Huang
 *  Date: 04/27/2021
 */
/**
 *  Get Logcat output by getOutput("logcat *:S TAG -d")
 */
fun getOutput(command: String): String? {
    val proc = Runtime.getRuntime().exec(command)

    try {
        val stdInput = BufferedReader(
            InputStreamReader(
                proc.inputStream
            )
        )
        val output = StringBuilder()
        var line: String? = ""
        //var counter = 0
        while (stdInput.readLine().also { line = it } != null) {
            //counter += 1
            //lgd("line #$counter = $line")
            output.append(line+"\n")
        }
        stdInput.close()
        return output.toString()
    } catch (e: IOException) {
        e.printStackTrace()
    }
    return null
}

/**
 *  clear logcat buffer
 */
fun clearLog() {
    Runtime.getRuntime().exec("logcat -c")
}

📳 輸入測驗

/**
 *  Test: Input the message;
 *        start the service;
 *        and check logcat
 */
@Test
fun message_input_service_uiautomator() {
    // buttons
    val msgInput = mDevice!!.findObject(
        res("${APPLICATION_ID}:id/et_message"))
    val startBt = mDevice!!.findObject(
        res("${APPLICATION_ID}:id/bt_start"))
    val stopBt = mDevice!!.findObject(
        res("${APPLICATION_ID}:id/bt_stop"))

    // clear Logcat buffer
    clearLog()

    // input
    val toServiceStr = "This is a test."
    msgInput.text = toServiceStr
    Thread.sleep(1000)

    lgd("start bt: ${startBt.resourceName}")
    startBt.click()

    Thread.sleep(1000)

    lgd("stop bt: ${stopBt.resourceName}")
    stopBt.click()

    val param = "logcat *:S MLOG -d"
    lgd("param: $param")
    val mLog = getOutput(param)

    Thread.sleep(500)

    lgd("mlog: $mLog")

    Truth.assertThat(mLog?.contains("Input: $toServiceStr"))
        .isTrue()
}

跑啊！截取 Logcat：

mlog: --------- beginning of main
    04-27 14:06:29.582 31368 31368 D MLOG    : mainAct: Permission: android.permission.WAKE_LOCK = true
    04-27 14:06:31.459 31368 31400 D MLOG    : start bt: com.homan.huang.servicedemo:id/bt_start
    04-27 14:06:31.504 31368 31368 D MLOG    : MainAct: start button clicked!
    04-27 14:06:31.504 31368 31368 D MLOG    : input text: This is a test.
    04-27 14:06:31.527 31368 31419 D MLOG    : onHandleWork
    04-27 14:06:31.527 31368 31419 D MLOG    : MyIntentService: Service is running...
    04-27 14:06:31.528 31368 31419 D MLOG    : Intent Extra: null
    04-27 14:06:31.528 31368 31419 D MLOG    : receive text from LiveData: This is a test.
    04-27 14:06:31.528 31368 31419 D MLOG    : Input: This is a test. - 0
    04-27 14:06:32.495 31368 31400 D MLOG    : stop bt: com.homan.huang.servicedemo:id/bt_stop
    04-27 14:06:32.519 31368 31400 D MLOG    : param: logcat *:S MLOG -d
    04-27 14:06:32.525 31368 31368 D MLOG    : MainAct: stop button clicked!
    04-27 14:06:32.525 31368 31368 D MLOG    : MyIntentService: Service is stopping...

測驗通過！

🍞 10. 英文版

幫幫忙，拍拍手！
英文連接： 💉Inject LiveData into JobIntentService and How to🔫 Test It

轉載請註明出處，本文鏈接：https://www.uj5u.com/yidong/282642.html

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啪！啪！給 JobIntentService 打針， Hilt 號的大針，看你爽不爽？哎呦，Espresso 看不到結果，用 UiAutomator 測。