Android 7.0以上系統獲取文件拿不到正確路徑，報錯column-data-does-not-exist

簡介：
上一篇文章【Android 選擇文件並返回路徑】中介紹了選擇文件並返回文件路徑的示例。使用過程中發現，Android 7.0以上系統通過手機自帶的文件管理選擇文件，程序崩潰，參考網上方法，優化選擇文件的功能。

效果圖:

1. 文件選擇器類

public class ContentUriUtil {

    /**
     * Get a file path from a Uri. This will get the the path for Storage Access
     * Framework Documents, as well as the _data field for the MediaStore and
     * other file-based ContentProviders.
     *
     * @param context The context.
     * @param uri The Uri to query.
     * @author paulburke
     */
    public static String getPath(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }

                // TODO handle non-primary volumes
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[] {
                        split[1]
                };

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {

            // Return the remote address
            if (isGooglePhotosUri(uri))
                return uri.getLastPathSegment();

            if (Build.VERSION.SDK_INT >= 24) {
                return getFilePathFromURI(context, uri);
            } else {
                return getDataColumn(context, uri, null, null);
            }
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }

        return null;
    }

    public static String getFilePathFromURI(Context context, Uri contentUri) {
        File rootDataDir = context.getFilesDir();
        String fileName = getFileName(contentUri);
        if (!TextUtils.isEmpty(fileName)) {
            File copyFile = new File(rootDataDir + File.separator + fileName);
            copyFile(context, contentUri, copyFile);
            return copyFile.getAbsolutePath();
        }
        return null;
    }

    public static String getFileName(Uri uri) {
        if (uri == null) return null;
        String fileName = null;
        String path = uri.getPath();
        int cut = path.lastIndexOf('/');
        if (cut != -1) {
            fileName = path.substring(cut + 1);
        }
        return fileName;
    }

    public static void copyFile(Context context, Uri srcUri, File dstFile) {
        try {
            InputStream inputStream = context.getContentResolver().openInputStream(srcUri);
            if (inputStream == null) return;
            OutputStream outputStream = new FileOutputStream(dstFile);
            copyStream(inputStream, outputStream);
            inputStream.close();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static int copyStream(InputStream input, OutputStream output) throws Exception, IOException {
        final int BUFFER_SIZE = 1024 * 2;
        byte[] buffer = new byte[BUFFER_SIZE];
        BufferedInputStream in = new BufferedInputStream(input, BUFFER_SIZE);
        BufferedOutputStream out = new BufferedOutputStream(output, BUFFER_SIZE);
        int count = 0, n = 0;
        try {
            while ((n = in.read(buffer, 0, BUFFER_SIZE)) != -1) {
                out.write(buffer, 0, n);
                count += n;
            }
            out.flush();
        } finally {
            try {
                out.close();
            } catch (IOException e) {
            }
            try {
                in.close();
            } catch (IOException e) {
            }
        }
        return count;
    }

    /**
     **
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context The context.
     * @param uri The Uri to query.
     * @param selection (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public static String getDataColumn(Context context, Uri uri, String selection,
                                       String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {
                column
        };

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst()) {
                final int index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is Google Photos.
     */
    public static boolean isGooglePhotosUri(Uri uri) {
        return "com.google.android.apps.photos.content".equals(uri.getAuthority());
    }

    /**
     * 判斷是否爲txt文件
     * @param path 文件路徑
     * @return
     */
    public static boolean isFile(String path) {
        if (null == path || path.isEmpty() || !path.contains("txt"))
            return false;
        File file = new File(path);
        return file.isFile();
    }

}

2. 主界面

public class Main2Activity extends AppCompatActivity {

    private TextView filePath;
    private Button btnSelect;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        filePath = findViewById(R.id.file_path);
        btnSelect = findViewById(R.id.open_file);

        btnSelect.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                openSystemFile();
            }
        });
    }

    public void openSystemFile() {
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        // 所有類型
        intent.setType("*/*");
        intent.addCategory(Intent.CATEGORY_DEFAULT);
        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
        try {
            startActivityForResult(Intent.createChooser(intent, "請選擇文件"), 1);
        } catch (ActivityNotFoundException e) {
            e.printStackTrace();
            Toast.makeText(Main2Activity.this, "請安裝文件管理器", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
            //Get the Uri of the selected file
            Uri uri = data.getData();
            if (null != uri) {
                String path = ContentUriUtil.getPath(this, uri);
                Log.i("filepath", " = " + path);
                updateFilePath(path);
            }
        }
    }

    private void updateFilePath(final String path) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                filePath.setText(path);
            }
        });
    }

}

3. 界面文件

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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"
    tools:context=".Main2Activity">

    <TextView
        android:id="@+id/file_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="文件路徑:"
        android:textSize="18sp"
        android:textColor="#353535"
        android:layout_marginTop="60dp"
        android:layout_marginStart="40dp"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"/>

    <TextView
        android:id="@+id/file_path"
        android:layout_width="160dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        app:layout_constraintTop_toTopOf="@id/file_name"
        app:layout_constraintBottom_toBottomOf="@id/file_name"
        app:layout_constraintLeft_toRightOf="@id/file_name"/>

    <Button
        android:id="@+id/open_file"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="選擇文件"
        android:background="@drawable/button_corner"
        app:layout_constraintLeft_toRightOf="@id/file_path"
        app:layout_constraintTop_toTopOf="@id/file_name"
        app:layout_constraintBottom_toBottomOf="@id/file_name"/>

</androidx.constraintlayout.widget.ConstraintLayout>