Android从手机内部存储读取JSON

Question

当您阅读标题时，我正在尝试从手机下载文件夹中读取 JSON 文件。 但它一直给我错误提示，这是我在其中一个函数中实现的（获取文件路径时出错）。

这是 github 链接 https://github.com/giorgishubitidze3/Blaezar

主要功能可以在UploadFragment和viewModel中找到

编辑：我添加了这个 testPush 函数用于测试目的，它给了我 即使我授予应用程序所需的所有权限，FileNotFoundException 也会出现 EACCES（权限被拒绝）错误。 （也将它们添加到清单文件中）

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>

fun testPush(){
        val file = 
File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS), 
"ads_interests.json")
        val result = file.readText()
        myDataReference.setValue(result)
    }

private fun openFilePicker() {
        val intent = Intent(Intent.ACTION_GET_CONTENT)
        intent.type = "*/*"
        intent.addCategory(Intent.CATEGORY_OPENABLE)
        intent.putExtra(Intent.EXTRA_MIME_TYPES, arrayOf("application/json", "application/zip"))

        val tempFile = createTempFile("temp", ".json", requireContext().getExternalFilesDir(null))

        val fileUri = FileProvider.getUriForFile(
            requireContext(),
            "${requireContext().packageName}.fileprovider",
            tempFile
        )

        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri)
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)

        startActivityForResult(intent, FILE_PICK_REQUEST_CODE)
    }

override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        if (requestCode == FILE_PICK_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
            data?.data?.let { uri ->
                val filePath = getPathFromUri(requireActivity().application, uri)
                if (filePath != null) {
                    view?.findViewById<TextView>(R.id.selectedItemTv)?.text =
                        "Selected item: $filePath"
                    selectedFileUri = Uri.parse("file://$filePath")
                } else {
                    Toast.makeText(requireContext(), "Error getting file path", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }

private fun getPathFromUri(application: Application, uri: Uri): String? {
        var path: String? = null
        try {
            val cursor = application.contentResolver.query(uri, null, null, null, null)
            cursor?.use {
                if (it.moveToFirst()) {
                    val columnIndex = it.getColumnIndex(MediaStore.Images.Media.DATA)
                    if (columnIndex != -1) {
                        path = it.getString(columnIndex)
                    }
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return path
    }

fun handleFileSelection(
        application: Application,
        appContext: Context,
        fileUri: Uri,
        callback: (String) -> Unit
    ) {
        viewModelScope.launch(Dispatchers.IO) {
            val fileName = getFileName(application, fileUri)
            if (fileName != null) {
                callback(fileName)
            }

            try {
                // Read the JSON file from the assets folder
                val inputStream = fileName?.let { appContext.assets.open(it) }
                val reader = BufferedReader(InputStreamReader(inputStream))
                val jsonString = reader.use { it.readText() }

                // Parse JSON using Gson
                val gson = Gson()
                val jsonData = gson.fromJson(jsonString, jsonData::class.java)

                // Upload interests to Firebase
                uploadInterests(jsonData)
            } catch (e: Exception) {
                e.printStackTrace()
                // Handle any errors during file reading or Firebase upload
                // For example, show an error message to the user
                callback("Error: $e")
            }
        }
    }

Answer 1

当我在 android 清单文件应用程序标记中添加 android:requestLegacyExternalStorage="true" 时，问题已得到解决

还稍微清理了代码并使其工作。

 uploadButton.setOnClickListener {
            openFilePicker()
        }

 sendButton.setOnClickListener {
            if (fileNamee != null || fileNamee != " ") {
                val fileName = fileNamee
                fileName?.let { it1 -> viewModel.testPush(it1) }
            } else {
                Toast.makeText(requireContext(), "No file selected", Toast.LENGTH_SHORT).show()
            }
        }

 private fun openFilePicker() {
        val intent = Intent(Intent.ACTION_GET_CONTENT)
        intent.type = "*/*"
        intent.addCategory(Intent.CATEGORY_OPENABLE)
        intent.putExtra(Intent.EXTRA_MIME_TYPES, arrayOf("application/json", "application/zip"))

        val tempFile = createTempFile("temp", ".json", requireContext().getExternalFilesDir(null))

        val fileUri = FileProvider.getUriForFile(
            requireContext(),
            "${requireContext().packageName}.fileprovider",
            tempFile
        )

        intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri)
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)

        startActivityForResult(intent, FILE_PICK_REQUEST_CODE)
    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        if (requestCode == FILE_PICK_REQUEST_CODE && resultCode == Activity.RESULT_OK) {
            data?.data?.let { uri ->
                val fileName = getFileNameFromUri(uri)
                if (fileName != null) {
                    view?.let { view ->
                        viewModel.setFileName(fileName, view.findViewById<TextView>(R.id.selectedItemTv)
                        )
                        fileNamee=fileName
                    }
                    Toast.makeText(requireContext(), "Selected file: $fileName", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "Error getting file name", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }


    private fun getFileNameFromUri(uri: Uri): String? {
        var fileName: String? = null
        try {
            val cursor = requireContext().contentResolver.query(uri, null, null, null, null)
            cursor?.use {
                if (it.moveToFirst()) {
                    val columnIndex = it.getColumnIndex(OpenableColumns.DISPLAY_NAME)
                    if (columnIndex != -1) {
                        fileName = it.getString(columnIndex)
                    }
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return fileName
    }

private val database = FirebaseDatabase.getInstance()
    private val myDataReference = database.reference

fun testPush(fileName: String){
        val file = File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS),
            fileName)
        val result = file.readText()
        myDataReference.setValue(result)
    }


    fun setFileName(name:String, textView: TextView){
        textView.text = name
    }