Android Datastore IOException could not be renamed to

问题

I am trying to implement Jetpack Datastore in my project. I was using the apha-01 version and the code was working fine. Then I saw in the Gradle file that there is a new version so I updated it to alpha-03.

After starting my app, I encountered another issue. I found that Proto library is not found in the alpha-03 version so I rolled back to version alpha-01. Also, I tried alpha-02. Since then I am having the error below:

 Process: com.montymobile.sands, PID: 19928
    java.io.IOException: /data/user/0/com.montymobile.sands/files/datastore/sns_preferences.preferences_pb.tmp could not be renamed to /data/user/0/com.montymobile.sands/files/datastore/sns_preferences.preferences_pb
        at androidx.datastore.SingleProcessDataStore.writeData$datastore_core_release(SingleProcessDataStore.kt:304)
        at androidx.datastore.SingleProcessDataStore.transformAndWrite(SingleProcessDataStore.kt:282)
        at androidx.datastore.SingleProcessDataStore$actor$1.invokeSuspend(SingleProcessDataStore.kt:165)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:56)
        at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:571)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:738)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:678)
        at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:665)

I noticed that this happens because I was saving two different key one after another, each in a coroutine. When i comment the 2nd action, it works. Can anyone explain why this happens? and how to save as many values as I Want?

Any help would be appreciated.

回答1:

Screenshot of the sime UI Check the following code.

class DataStoreClass(private val context: Context) {

    private fun dataStore(): DataStore<Preferences> = context.createDataStore("settings")

    suspend  fun <T> save(key: Preferences.Key<T>, value: T) {
        dataStore().edit {
            it[key] = value
        }
    }

    suspend fun <T> read(key: Preferences.Key<T>, defaultValue: T): T {
        val pre = dataStore().data.first()
        return pre[key] ?: defaultValue
    }

}

open class BaseActivity : AppCompatActivity() {

    inline fun <reified T> getSavedValue(key: String, defaultValue:T): Any {
         var savedValue = Any()
         runBlocking {
             val operation = async {
                 val savedStr = DataStoreClass(this@BaseActivity).read(preferencesKey(key),
                     defaultValue!!).let {
                     it
                 }
                 savedValue = savedStr
             }
             operation.await()
         }
         return savedValue
     }

    fun <T> saveDesiredValue(key: Preferences.Key<T>, value: T) {
        runBlocking {
            CoroutineScope(Dispatchers.IO).launch {
                DataStoreClass(this@BaseActivity).save(key, value)
            }.join()
        }
    }
}

class MainActivity : BaseActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val bnt = findViewById<Button>(R.id.btnSave)
        val btnRead = findViewById<Button>(R.id.btnRead)
        val key = findViewById<EditText>(R.id.key)
        val etValue = findViewById<EditText>(R.id.etValue)
        val value = findViewById<TextView>(R.id.value)

        bnt.setOnClickListener {
            saveDesiredValue(preferencesKey(key.text.toString()),etValue.text.toString())
            saveDesiredValue(preferencesKey("test"), Random.nextInt(100))

        }

        btnRead.setOnClickListener {
            value.text = "${getSavedValue(key.text.toString(),"")} " +
                    "${getSavedValue("test",0)}"
        }
    }
}

来源：https://stackoverflow.com/questions/64883210/android-datastore-ioexception-could-not-be-renamed-to