什么是最简单的方法从android.net.Uri对象持有一个文件:类型转换为java.io.File对象在Android?

我尝试了下面的方法,但不管用:

File file = new File(Environment.getExternalStorageDirectory(), "read.me");
Uri uri = Uri.fromFile(file);
File auxFile = new File(uri.toString());
assertEquals(file.getAbsolutePath(), auxFile.getAbsolutePath());

当前回答

添加onActivityResult,获取docx或pdf文件

var imageUriPath = ""
imageUriPath =
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    val split = (imageUri.path ? : "").split(":") //split the path.
    split[1]
  } else {
    imageUri.path ? : ""
  }
val file = File(imageUriPath)

其他回答

使用Kotlin甚至更容易:

val file = File(uri.path)

或者如果你在Android上使用Kotlin扩展:

val file = uri.toFile()

更新: 对于图像,它返回“Uri缺少'file' scheme: content://”

谢谢你的评论

使用内容解析器获取输入流

InputStream inputStream = getContentResolver().openInputStream(uri);

然后将输入流复制到文件中

FileUtils.copyInputStreamToFile(inputStream, file);

样品使用方法:

private File toFile(Uri uri) throws IOException {
        String displayName = "";
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);

        if(cursor != null && cursor.moveToFirst()){
            try {
                displayName = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
            }finally {
                cursor.close();
            }
        }

        File file =  File.createTempFile(
                FilenameUtils.getBaseName(displayName),
                "."+FilenameUtils.getExtension(displayName)
        );
        InputStream inputStream = getContentResolver().openInputStream(uri);
        FileUtils.copyInputStreamToFile(inputStream, file);
        return file;
    }

要正确地使用context uri获取文件, 感谢来自@Mohsents, @Bogdan Kornev, @CommonsWare, @Juan Camilo Rodriguez的回答Durán;

我从uri中创建了一个inputStream,并使用这个iStream创建了一个临时文件,最后我能够从这个文件中提取uri和路径。

fun createFileFromContentUri(fileUri : Uri) : File{

    var fileName : String = ""

    fileUri.let { returnUri ->
        requireActivity().contentResolver.query(returnUri,null,null,null)
    }?.use { cursor ->
        val nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
        cursor.moveToFirst()
        fileName = cursor.getString(nameIndex)
    }
    
    //  For extract file mimeType
    val fileType: String? = fileUri.let { returnUri ->
        requireActivity().contentResolver.getType(returnUri)
    }

    val iStream : InputStream = requireActivity().contentResolver.openInputStream(fileUri)!!
    val outputDir : File = context?.cacheDir!!
    val outputFile : File = File(outputDir,fileName)
    copyStreamToFile(iStream, outputFile)
    iStream.close()
    return  outputFile
}

fun copyStreamToFile(inputStream: InputStream, outputFile: File) {
    inputStream.use { input ->
        val outputStream = FileOutputStream(outputFile)
        outputStream.use { output ->
            val buffer = ByteArray(4 * 1024) // buffer size
            while (true) {
                val byteCount = input.read(buffer)
                if (byteCount < 0) break
                output.write(buffer, 0, byteCount)
            }
            output.flush()
        }
    }
}

public String getRealPathFromURI(Uri uri) {

    String result;
    Cursor cursor = getContentResolver().query(uri, null, null, null, null);
    if (cursor == null) {
        result = uri.getPath();
        cursor.close();
        return result;
    }
    cursor.moveToFirst();
    int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
    result = cursor.getString(idx);
    cursor.close();
    return result;
}

然后使用从URI中获取文件:

        File finalFile = newFile(getRealPathFromURI(uri));

——希望能帮到你----

扩展基于@Jacek kwiecievik回答转换图像uri文件

fun Uri.toImageFile(context: Context): File? {
    val filePathColumn = arrayOf(MediaStore.Images.Media.DATA)
    val cursor = context.contentResolver.query(this, filePathColumn, null, null, null)
    if (cursor != null) {
        if (cursor.moveToFirst()) {
            val columnIndex = cursor.getColumnIndex(filePathColumn[0])
            val filePath = cursor.getString(columnIndex)
            cursor.close()
            return File(filePath)
        }
        cursor.close()
    }
    return null
}

如果我们使用File(uri.getPath()),它将不起作用

如果我们使用扩展从android-ktx,它仍然不能工作,因为 https://github.com/android/android-ktx/blob/master/src/main/java/androidx/core/net/Uri.kt