Facebook: post a photo on a friend's wall

I'm trying to post a photo on the wall of a friend using RestFB, a Java API for Facebook. I tried various solutions like:

facebookClient.publish(fbu+"/photos/",FacebookType.class,new FileInputStream(pathOrig));

fbu is the Facebook user id of the friend. This code actually posts the photo on my wall!

facebookClient.publi开发者_如何学JAVAsh(fbu+"/feed/",FacebookType.class,new FileInputStream(pathOrig),Parameter.with("message",message));

This code posts the message on my friend's wall, but without the photo.

Strangely, it's possible using directly Facebook to upload photos on friends wall, so it should be possible using Graph, in my opinion...

Any clue?

---

You can't post a photo on your friends wall. You can, however, upload a photo and tag your friend in it.

According to the Photo Documentation you set the tags on a photo by setting the tags parameter on the graph request, and formatting like so:

[{
    "tag_uid": <fb uid>,
    "x":74,
    "y":62
},
{
    "tag_uid": <fb uid 2>,
    "x":8,
    "y":27
}]

Each object is the has your friend's FBuid and the x and y position of the tag location on the photo.

You can, however, publish a link on your friend's wall to a photo and have the link go off Facebook for them to view it. This is probably not what you're looking to do, but it's an option.