Asmack源码入门

Smack的初始化涉及到两个步骤： 1.初始化系统属性——通过SmackConfiguration进行系统属性初始化。这些属性可以通过getxxx()方法获

Smack的初始化涉及到两个步骤：

1.初始化系统属性——通过SmackConfiguration进行系统属性初始化。这些属性可以通过getxxx()方法获取。

2.初始化启动类——初始化类意味着在启动时候实例化该类，如果继承SmackInitializer则需要调用initialize()方法。如果不继承SmackInitializer则初始化的操作必须在静态代码块中，一旦加载类时自动执行。

Establishing a Connection创建连接

XmppTCPConnection类是被用来创建连接到xmpp服务器的。

// Create a connection to the jabber.org server._

XMPPConnection conn1 = new XMPPTCPConnection("jabber.org");

conn1.connect();

// Create a connection to the jabber.org server on a specific port._

ConnectionConfigurationconfig = new ConnectionConfiguration("jabber.org", 5222);

XMPPConnection conn2 = new XMPPTCPConnection(config);

conn2.connect();

ConectionConfiguration类提供一些控制操作，譬如是否加密。

Working with the Roster 花名册

Roster可以让你保持获取其他用户的presence状态，用户可以添加进组“Friend”或者“Co-workers”，你可以知晓用户是否在线。

检索roster可以通过XMPPConnection.getRoster()方法，roster类允许你查看所有的roster enteries ,群组信息当前的登录状态。

Reading and WritingPackets读写数据包

XMPP服务器和客户端间以XML传递的信息被称为数据包。

org.jivesoftware.smack.packet包内有三种封装好的基本的packet，分别是message, presence和IQ。

比如Chat和GroupChat类提供了更高级别的结构用以创建发送packet，当然你也可以直接用packet。

// 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 packet (assume we have aXMPPConnection instance called "con").

con.sendPacket(presence);

Smack提供两种读取packets

PacketListener和PacketCollector，这两种都通过PacketFilter进行packet加工。

A packet listener is used for event style programming, while a packet collector has a result queue of packets that you can do polling and blocking operations on.

（packet listener事件监听，而packet collector是一个packets的可以进行polling和blocking操作的结果集队列。）

So, a packet listener is useful when you want to take some action whenever a packet happens to come in, while a packet collector is useful when you want to wait for a specific packet to arrive.

（packet listener一旦数据包传递抵达的时候你可以进行处理，packet collector则被使用在你需要等待一个指定的packet传递抵达时候。）

Packet collectors and listeners can be created using an Connection instance.

（packet listener和packet collector在connection实例中被创建。）

// Create a packet filter to listen for new messages from a particular

// user. We use an AndFilter to combine two other filters._

PacketFilter filter = new AndFilter(new PacketTypeFilter(Message.class),

newFromContainsFilter("mary@jivesoftware.com"));

// Assume we've created a XMPPConnection name "connection".

// First, register a packet collector using the filter we created.

PacketCollectormyCollector = connection.createPacketCollector(filter);

// Normally, you'd do something with the collector, like wait for new packets.

// Next, create a packet listener. We use an anonymous inner class for brevity.

PacketListenermyListener = new PacketListener() {

public void processPacket(Packet packet) {

// Do something with the incoming packet here._

}

};

// Register the listener._

connection.addPacketListener(myListener, filter);

Managing Connection

Connect and disConnect

// Create the configuration for this new connection_

ConnectionConfigurationconfig = new ConnectionConfiguration("jabber.org", 5222);

AbstractXMPPConnection connection = new XMPPTCPConnection(config);

// Connect to the server_

connection.connect();

// Log into the server_

connection.login("username", "password", "SomeResource");

...

// Disconnect from the server_

connection.disconnect();

Messaging using Chat

Chat

org.jivesoftware.smack.Chat

// Assume we've created a XMPPConnection name "connection"._

ChatManagerchatmanager = connection.getChatManager();

Chat newChat = chatmanager.createChat("jsmith@jivesoftware.com", new MessageListener() {

public void processMessage(Chat chat, Message message) {

System.out.println("Received message: " + message);

}

});

try {

newChat.sendMessage("Howdy!");

}

catch (XMPPException e) {

System.out.println("Error Delivering block");

}

Message newMessage = new Message();

newMessage.setBody("Howdy!");

message.setProperty("favoriteColor", "red");

newChat.sendMessage(newMessage);

// Assume a MessageListener we've setup with a chat._

public void processMessage(Chat chat, Message message) {

// Send back the same text the other user sent us._

chat.sendMessage(message.getBody());

}

incoming Chat

_// Assume we've created a XMPPConnection name "connection"._

ChatManagerchatmanager = connection.getChatManager().addChatListener(

newChatManagerListener() {

@Override

public void chatCreated(Chat chat, booleancreatedLocally)

{

if (!createdLocally)

chat.addMessageListener(new MyNewMessageListener());;

}

});

Roster and Presence

roster entries

包含xmpp地址，备注名，群组（假如该用户不属于任何一组，则调用“unfiled entry”）：

Roster roster = connection.getRoster();

Collection entries = roster.getEntries();

for (RosterEntry entry : entries) {

System.out.println(entry);

}

监听roster和presence更改：

Roster roster = con.getRoster();

roster.addRosterListener(new RosterListener() {

// Ignored events public void entriesAdded(Collection addresses) {}

public void entriesDeleted(Collection addresses) {}

public void entriesUpdated(Collection addresses) {}

public void presenceChanged(Presence presence) {

System.out.println("Presence changed: " + presence.getFrom() + " " + presence);

}

});

Provider architecture

smack provider是用于解析packet extension 和 IQ xml流的，有两种类型的provider：

IQProvider -parses IQ request into java objects

Extension Provider - parses XML sub-documents attached to packets into PacketExtension instances. By default, Smack only knows how to process a few standard packets and sub-packets that are in a few namespaces such as:

(解析packet的xml子元素到PacketExtension实例中。Smack默认仅知道处理少数的标准packets和少数的指定的namespaces下的子packets)