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Smack/documentation/extensions/hoxt.md

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HTTP over XMPP transport
========================
Allows to transport HTTP communication over XMPP peer-to-peer networks.
* Discover HOXT support
* IQ exchange
Discover HOXT support
---------------------
**Description**
Before using this extension you must ensure that your counterpart supports it
also.
**Usage**
Once you have your _**ServiceDiscoveryManager**_ you will be able to discover
information associated with an XMPP entity. To discover the information of a
given XMPP entity send **discoverInfo(entityID)** to your
_**ServiceDiscoveryManager**_ where entityID is the ID of the entity. The
message **discoverInfo(entityID)** will answer an instance of
_**DiscoverInfo**_ that contains the discovered information.
**Examples**
In this example we can see how to check if the counterpart supports HOXT:
```
// Obtain the ServiceDiscoveryManager associated with my XMPPConnection
ServiceDiscoveryManager discoManager = ServiceDiscoveryManager.getInstanceFor(connection);
// Get the information of a given XMPP entity
DiscoverInfo discoInfo = discoManager.discoverInfo("juliet@capulet.com");
// Check if room is HOXT is supported
discoInfo.containsFeature("urn:xmpp:http");
```
IQ exchange
-----------
**Description**
You can use IQ's to perform HTTP requests and responses. This is applicable to
relatively short requests and responses (due to limitation of XMPP message
size).
**Usage**
First you need to register a _**PacketListener**_ to be able to handle
intended IQs.
For the HTTP client you:
* You create and send _**HttpOverXmppReq**_ request.
* Then you handle the _**HttpOverXmppResp**_ response in your _**PacketListener**_.
For the HTTP server you:
* You handle the _**HttpOverXmppReq**_ requests in your _**PacketListener**_.
* And create and send _**HttpOverXmppResp**_ responses.
**Examples**
In this example we are HTTP client, so we send request (POST) and handle the
response:
```
// create a request body
String urlEncodedMessage = "I_love_you";
// create request
HttpOverXmppReq req = new HttpOverXmppReq(HttpMethod.POST, "/mailbox");
req.setVersion("1.1");
// prepare headers
List<Header> list = new ArrayList<Header>();
list.add(new Header("Host", "juliet.capulet.com"));
list.add(new Header("Content-Type", "application/x-www-form- urlencoded"));
list.add(new Header("Content-Length", Integer.toString(urlEncodedMessage.length())));
req.setHeaders(new HeadersExtension(list));
// provide body or request (not mandatory, - empty body is used for GET)
AbstractHttpOverXmpp.Text child = new AbstractHttpOverXmpp.Text(urlEncodedMessage);
AbstractHttpOverXmpp.Data data = new AbstractHttpOverXmpp.Data(child);
req.setData(data);
// add to
req.setTo("juliet@capulet.com/balcony");
// send it
connection.sendIqWithResponseCallback(req, new PacketListener() {
public void processStanza(Stanza iq) {
HttpOverXmppResp resp = (HttpOverXmppResp) iq;
// check HTTP response code
if (resp.getStatusCode() == 200) {
// get content of the response
NamedElement child = resp.getData().getChild();
// check which type of content of the response arrived
if (child instanceof AbstractHttpOverXmpp.Xml) {
// print the message and anxiously read if from console ;)
System.out.println(((AbstractHttpOverXmpp.Xml) child).getText());
} else {
// process other AbstractHttpOverXmpp.DataChild subtypes
}
}
}
});
```