修改自：https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooser/src/com/ipaulpro/afilechooser/utils/FileUtils.java
原帖：https://stackoverflow.com/questions/19985286/convert-content-uri-to-actual-path-in-android-4-4

import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.database.DatabaseUtils;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;

public class ContentUriUtils {
//修改自https://github.com/iPaulPro/aFileChooser/blob/master/aFileChooser/src/com/ipaulpro/afilechooser/utils/FileUtils.java
//原帖：https://stackoverflow.com/questions/19985286/convert-content-uri-to-actual-path-in-android-4-4

    /**
     * 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.<br>
     * <br>
     * Callers should check whether the path is local before assuming it
     * represents a local file.
     *
     * @param context The context.
     * @param uri     The Uri to query.
     * @author paulburke
     */
    public static String getPath(final Context context, final Uri uri) {


        // DocumentProvider
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
            if (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];
                    }

                }
                // 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();

                return getDataColumn(context, uri, null, null);
            }
            // File
            else if ("file".equalsIgnoreCase(uri.getScheme())) {
                return uri.getPath();
            }
        }

        return null;
    }

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

    /**
     * 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.
     * @author paulburke
     */
    private 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()) {
                DatabaseUtils.dumpCursor(cursor);
                final int column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }
}