Android Uri到Filesize

import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.provider.OpenableColumns;

import java.io.File;

public class FileUtil {
    public static long getFileSizeFromUri(Context context, Uri uri) {
        Cursor cursor = null;
        try {
            cursor = context.getContentResolver().query(uri, null, null, null, null);
            if (cursor != null && cursor.moveToFirst()) {
                int sizeIndex = cursor.getColumnIndex(OpenableColumns.SIZE);
                if (sizeIndex != -1) {
                    return cursor.getLong(sizeIndex);
                }
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }
        return 0;
    }

    public static String formatFileSize(long size) {
        if (size <= 0) {
            return "0 B";
        }
        final String[] units = new String[]{"B", "KB", "MB", "GB", "TB"};
        int digitGroups = (int) (Math.log10(size) / Math.log10(1024));
        return String.format("%.1f %s", size / Math.pow(1024, digitGroups), units[digitGroups]);
    }
}