Trigger mediascanner on specific path (folder), how to?

Question

I got this class:

import android.content.Context;
import android.media.MediaScannerConnection;
import android.net.Uri;
import android.util.Log;

public class MediaScannerWrapper implements  
MediaScannerConnection.MediaScannerConnectionClient {
    private MediaScannerConnection mConnection;
    private String mPath;
    private String mMimeType;


    // filePath - where to scan; 
    // mime type of media to scan i.e. "image/jpeg". 
    // use "*/*" for any media
    public MediaScannerWrapper(Context ctx, String filePath, String mime){
        mPath = "/sdcard/DCIM/Camera";
        mMimeType = "jpg";
        mConnection = new MediaScannerConnection(ctx, this);
    }

    // do the scanning
    public void scan() {
        mConnection.connect();
    }

    // start the scan when scanner is ready
    public void onMediaScannerConnected() {
        mConnection.scanFile(mPath, mMimeType);
        Log.w("MediaScannerWrapper", "media file scanned: " + mPath);
    }

    public void onScanCompleted(String path, Uri uri) {
        // when scan is completes, update media file tags
    }
}

How to use it in the other class? I don't know how to properly use classes, I tried but nothing is working. I do something wrong, but I don't know what, can someone help me with this.