Android Kotlin文件保存錯誤如何解決

Question

如何解決？ 我創建了一個程序，定期創建手機傳感器數據並將其存儲在手機下載文件夾中的一個文件中。 第一次運行沒問題，但是如果要再次新建文件，刪除path文件夾下的文件再運行，就會出現EExit錯誤。 以文件已經存在於 /storage/emulator/0/~~ 路徑中的方式。 我應該怎么做才能修復此錯誤？ 寫入文件的代碼如下。

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

        setChart()
        checkFunction()

        val saveButton: Button = findViewById(R.id.btn_save)
        saveButton.setOnClickListener{
            if(isSaving){
                // Stop saving data
                isSaving = false
                saveButton.text = "Save Start"
                // Display a toast message to confirm that the data was saved
                Toast.makeText(this, "Stop Sensor data saved to file", Toast.LENGTH_SHORT).show()
            } else {
                // Start saving data
                isSaving = true
                saveButton.text = "Save Stop"

                // Check if app has permission to write to external storage
                if(ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                != PackageManager.PERMISSION_GRANTED){
                    //Request permission if it doesn't already have it
                    ActivityCompat.requestPermissions(this, permission_list, 1)
                } else {
                    // Display a toast message to confirm that the data was saved
                    Toast.makeText(this, "Start Sensor data saved to file", Toast.LENGTH_SHORT).show()
                    // Define file
                    saveCounter++
                    // if permission is already granted, start saving sensor data in a background thread
                    GlobalScope.launch(Dispatchers.IO) {
                        while(isSaving){
                            saveSensorDataToFile()
                            delay(1000)
                        }
                    }

                }
            }
        }
    }

// -------------------- Save Data at File -------------------

    private fun saveSensorDataToFile() {
        if (ActivityCompat.checkSelfPermission(
                this,
                Manifest.permission.WRITE_EXTERNAL_STORAGE
            ) == PackageManager.PERMISSION_GRANTED
        ) {
            // Get the path to the exteranl storage
            val root = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS)
            val dir = File(root.path + "/SensorData3")
            dir?.mkdirs()
            val fileName = "Sensor_data_$saveCounter.txt"
            val file = File(dir, fileName)
            val sdf = SimpleDateFormat("MM-dd HH:mm:ss", Locale.getDefault())
            val currentDate = sdf.format(Date())
            val data = "$currentDate, $pre_x, $acc_x, $acc_y, $acc_z\n"
            file.appendText(data)
        } else {
            // Permission not granted, request permission
            ActivityCompat.requestPermissions(
                this,
                arrayOf(Manifest.permission.WRITE_EXTERNAL_STORAGE),
                0
            )
        }
    }

    // 권한 확인 함수
    private fun checkFunction() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
            && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED
            && ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)
                && ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_COARSE_LOCATION)
                && ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                ActivityCompat.requestPermissions(this, arrayOf(
                    Manifest.permission.ACCESS_FINE_LOCATION,
                    Manifest.permission.ACCESS_COARSE_LOCATION,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE), 101)
            } else {
                ActivityCompat.requestPermissions(this, arrayOf(
                    Manifest.permission.ACCESS_FINE_LOCATION,
                    Manifest.permission.ACCESS_COARSE_LOCATION,
                    Manifest.permission.WRITE_EXTERNAL_STORAGE), 101)
            }
        }
    }


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="10"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:orientation="horizontal">

            <TextView
                android:id="@+id/tv_acc"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="acc_value"
                android:textSize="20dp"
                android:textAlignment="center"
                android:gravity="center"/>

            <TextView
                android:id="@+id/tv_pressure"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="pressure_value"
                android:textSize="20dp"
                android:textAlignment="center"
                android:gravity="center"/>

        </LinearLayout>


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:orientation="horizontal">

            <com.github.mikephil.charting.charts.LineChart
                android:id="@+id/chart_accX"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="2"/>

            <com.github.mikephil.charting.charts.LineChart
                android:id="@+id/chart_accY"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="2"/>

            <com.github.mikephil.charting.charts.LineChart
                android:id="@+id/chart_accZ"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="2"/>

        </LinearLayout>

        <com.github.mikephil.charting.charts.LineChart
            android:id="@+id/chart_pressure"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="2"/>

    </LinearLayout>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:id="@+id/btn_save"
        android:text="Save Start"
        android:textSize="20dp"/>

</LinearLayout>

Answer 1

val file = File(dir, fileName)
var fileExists = file.exists()

if(fileExists){
   // file already there. so delete and new here
} else {
   // create new file
}