120 lines
6.1 KiB
Markdown
120 lines
6.1 KiB
Markdown
Smack: Getting Started
|
|
======================
|
|
|
|
[Back](index.md)
|
|
|
|
This document will introduce you to the Smack API and provide an overview of
|
|
important classes and concepts.
|
|
|
|
Smack Modules and Requirements
|
|
-------------------------------
|
|
|
|
Smack is meant to be easily embedded into any existing Java application. The
|
|
library ships as several modules to provide more flexibility over which
|
|
features applications require:
|
|
|
|
* `smack-core` -- provides core XMPP functionality. All XMPP features that are part of the XMPP RFCs are included.
|
|
* `smack-im` -- provides functionality defined in RFC 6121 (XMPP-IM), like the Roster.
|
|
* `smack-tcp` -- support for XMPP over TCP. Includes XMPPTCPConnection class, which you usually want to use
|
|
* `smack-extensions` -- support for many of the extensions (XEPs) defined by the XMPP Standards Foundation, including multi-user chat, file transfer, user search, etc. The extensions are documented in the [extensions manual](extensions/index.md).
|
|
* `smack-experimental` -- support for experimental extensions (XEPs) defined by the XMPP Standards Foundation. The API and functionality of those extensions should be considered as unstable.
|
|
* `smack-legacy` -- support for legacy extensions (XEPs) defined by the XMPP Standards Foundation.
|
|
* `smack-bosh` -- support for BOSH (XEP-0124). This code should be considered as beta.
|
|
* `smack-resolver-minidns` -- support for resolving DNS SRV records with the help of MiniDNS. Ideal for platforms that do not support the javax.naming API. Also supports [DNSSEC](dnssec.md).
|
|
* `smack-resolver-dnsjava` -- support for resolving DNS SRV records with the help of dnsjava.
|
|
* `smack-resolver-javax` -- support for resolving DNS SRV records with the javax namespace API.
|
|
* `smack-debug` -- an enhanced GUI debugger for protocol traffic. It will automatically be used when found in the classpath and when [debugging](debugging.md) is enabled.
|
|
|
|
Configuration
|
|
-------------
|
|
|
|
Smack has an initialization process that involves 2 phases.
|
|
|
|
* Initializing system properties - Initializing all the system properties accessible through the class **SmackConfiguration**. These properties are retrieved by the _getXXX_ methods on that class.
|
|
* Initializing startup classes - Initializing any classes meant to be active at startup by instantiating the class, and then calling the _initialize_ method on that class if it extends **SmackInitializer**. If it does not extend this interface, then initialization will have to take place in a static block of code which is automatically executed when the class is loaded.
|
|
|
|
Initialization is accomplished via a configuration file. By default, Smack
|
|
will load the one embedded in the Smack jar at _org.jivesoftware.smack/smack-
|
|
config.xml_. This particular configuration contains a list of initializer
|
|
classes to load. All manager type classes that need to be initialized are
|
|
contained in this list of initializers.
|
|
|
|
Establishing a Connection
|
|
-------------------------
|
|
|
|
The `XMPPTCPConnection` class is used to create a connection to an XMPP
|
|
server. Below are code examples for making a connection:
|
|
|
|
```
|
|
// Create a connection and login to the example.org XMPP service.
|
|
AbstractXMPPConnection conn1 = new XMPPTCPConnection("username", "password", "example.org");
|
|
conn1.connect().login();
|
|
```
|
|
|
|
Further connection parameters can be configured by using a configuration builder:
|
|
|
|
```
|
|
// Create a connection to the jabber.org server on a specific port.
|
|
XMPPTCPConnectionConfiguration config = XMPPTCPConnectionConfiguration.builder()
|
|
.setUsernameAndPassword("username", "password")
|
|
.setXmppDomain("jabber.org")
|
|
.setHost("earl.jabber.org")
|
|
.setPort(8222)
|
|
.build();
|
|
|
|
AbstractXMPPConnection conn2 = new XMPPTCPConnection(config);
|
|
conn2.connect().login();
|
|
```
|
|
|
|
Note that maximum security will be used when connecting to the server by
|
|
default (and when possible), including use of TLS encryption. The
|
|
ConnectionConfiguration class provides advanced control over the connection
|
|
created, such as the ability to disable or require encryption. See
|
|
[XMPPConnection Management](connections.md) for full details.
|
|
|
|
Once you've created a connection, you should login with the
|
|
`XMPPConnection.login()` method. Once you've logged in, you can begin
|
|
chatting with other users by creating new `Chat` or `MultiUserChat`
|
|
objects.
|
|
|
|
Working with the Roster
|
|
----------------------
|
|
|
|
The roster lets you keep track of the availability (presence) of other users.
|
|
Users can be organized into groups such as "Friends" and "Co-workers", and
|
|
then you discover whether each user is online or offline.
|
|
|
|
Retrieve the roster using the `Roster.getInstanceFor(XMPPConnection)` method. The roster
|
|
class allows you to find all the roster entries, the groups they belong to,
|
|
and the current presence status of each entry.
|
|
|
|
Reading and Writing Stanzas
|
|
|
|
Each message to the XMPP server from a client is called a packet and is sent
|
|
as XML. The `org.jivesoftware.smack.packet` package contains classes that
|
|
encapsulate the three different basic packet types allowed by XMPP (message,
|
|
presence, and IQ). Classes such as `Chat` and `GroupChat` provide higher-level
|
|
constructs that manage creating and sending packets automatically, but you can
|
|
also create and send packets directly. Below is a code example for changing
|
|
your presence to let people know you're unavailable and "out fishing":
|
|
|
|
```
|
|
// Create a new presence. Pass in false to indicate we're unavailable._
|
|
Presence presence = new Presence(Presence.Type.unavailable);
|
|
presence.setStatus("Gone fishing");
|
|
// Send the stanza (assume we have an XMPPConnection instance called "con").
|
|
con.sendStanza(presence);
|
|
```
|
|
|
|
Smack provides two ways to read incoming packets: `StanzaListener`, and
|
|
`StanzaCollector`. Both use `StanzaFilter` instances to determine which
|
|
stanzas should be processed. A stanza listener is used for event style
|
|
programming, while a stanza collector has a result queue of packets that you
|
|
can do polling and blocking operations on. So, a stanza listener is useful
|
|
when you want to take some action whenever a stanza happens to come in, while
|
|
a stanza collector is useful when you want to wait for a specific packet to
|
|
arrive. Stanza collectors and listeners can be created using an Connection
|
|
instance.
|
|
|
|
Copyright (C) Jive Software 2002-2008
|