The document provides an overview of using BlazeDS to integrate Flex and Java applications. It discusses BlazeDS remoting services which allow Flex clients to invoke methods on Java objects, messaging services to enable publish-subscribe communication between Flex clients, and proxy services to integrate multiple external services. Code examples are provided for creating remote objects and producers/consumers to call remoting services and send/receive messages. Configuration files and settings for remoting, messaging and channels are also summarized.

1. 1
FLEX & JAVA USING
BLAZEDS
Hien Luu 2009 Silicon Valley Code Camp

2. About Me
2
 Senior Software Engineer at Netflix
 Many years with developing web-based
applications with Java technologies
 Instructor at UCSC-Extension school
 RIA with Flex & Java
 Spring Framework
 Design Patterns

3. Flex & Java Using BlazeDS
3
 Agenda
 BlazeDS Overview
 What & Why
 BlazeDS Tour
 BlazeDS Architecture
 BlazeDS Services
 Remoting
 Messaging
 Proxying
 Demo

4. Flex & Java Using BlazeDS
4
Quick Survey

5. BlazeDS Overview
5
 Open source project from Adobe – 12/07
 Smaller cousin of Adobe LifeCycle Data Services
Servlet Container
BlazeDS
Database
Your
Application

6. BlazeDS Overview
6
 Alternatives
Servlet Container
Your Java Database
application
PHP/Python
Granite, OpeAMF, Cinnamon,

7. AMF
7
 AMF (Action Message Format)
 Wire protocol
 Fast, small – 10x over XML
 AMF3 specification
 Open Source AMF Implementation
 AMFPHP
 OpenAMF
 rubyAMF
 PyAMF

8. BlazeDS Tour
8
 Download Turnkey version
 Include Tomcat 6.x
 BlazeDS sample applications
 Flex 3 SDK
 Unzip and start Tomcat and HSQL
 Come with sample database – product and census data
http://localhost:8400/

9. BlazeDS Architecture
9
BlazeDS Services
Access to enterprise
functionality
RPC Service
Let Flex clients
communicate with
each other
Messaging Service
asynchronously
Proxy service to
integrate multiple
services with a
Proxy Service single application

10. BlazeDS Architecture
10
Flex Client Architecture
Flex Client J2EE Server
BlazeDS Component
BlazeDS
RemoteObject
HTTPService
WebService
HTTP
Consumer
Producer AMF/AMFX
Channel Set
M
A
F
H
P
T
T

11. BlazeDS Architecture
11
BlazeDS Server Architecture
Message
MessageBrokerServlet Broker Service Destination Adapter
• AMFEndPoint
R RemotingService RemotingDestination
• HTTPEndPoint O
• StreamingAMFEndPoint U JavaAdapter
HttpProxyService
T HttpProxyDestination
E
HttpProxy
MessageService
Adapter
M
S MessageDestination
G ActionScript
Adapter
Security JMS
Check point
Adapter

12. BlazeDS Configuration
12
Filename Description
services-config.xml Top level configuration file. Contains security constraints
definitions. Logging settings. Basically common configurations
across services.
remoting-config.xml Remoting service definitions, such as destination.
proxy-config.xml Proxy service definitions for working with web services, HTTP.
remoting-config.xml Messaging service for publish & subscribe

13. BlazeDS Channels & EndPoints
13
 Channel set fallback mechanism
Channel Endpoint Description
AMFChannel AMFEndPoint Transport data over HTTP in binary
AMF format. Use for Remoting.
HTTPChannel HTTPEndPoint Transport data over HTTP in AMFX
format. User for Remoting.
StreamingAMFChannel StringAMFEndPoint Streams data in real time over HTTP
in binary AMF format. User for
Messaging.
StreamingHTTPChannel StreamingHTTPEndPoint Streams data over HTTP in AMFX
foramt.

14. BlazeDS Channels Behavior
14
Channel Description
Non-polling AMF & HTTP channel Good for Remoting
Piggybacking AMF & HTTP channel Enable queuing of messages along with responses to
any messages from client.
Polling AMF & HTTP channel Simple polling mechanism from client side to request
messages
Long polling AMF & HTTP channel To get pushed messages to client. Server parks the
poll request until data arrives for client.
Streaming channel Stream data in real-time. Available in HTTP 1.1 only.
Make sure servers are capable of handling large
concurrent connections

15. Remoting
15
 Invoke methods of Java objects on server side
 HTTP-based request/response data communication
 Use AMFChannel
 Advantages
 AMF binary messaging protocol for exchanging data
 Serialization/de-serialization are handled automatically
 Natively supported by Flash Player
 Gateway services make easier to expose server side
services
Why not use HTTPService or WebService?

16. Remoting
16
 RemoteObject – client side component
 destination– source of Remoting Service destination
 result – when service call successfully returns
 fault – when service call fails
 concurrency – how to handle multiple calls
 multiple – existing requests are not cancelled
 single – one at a time, multiple requests generate fault
 last – New request cancels any existing request

17. BlazeDS Architecture
17
BlazeDS Server Architecture
Message
MessageBrokerServlet Broker Service Destination Adapter
• AMFEndPoint
R RemotingService RemotingDestination
O
U JavaAdapter
T
E
M
S
G
Security
Check point

18. Remoting
18
<mx:Script>
private function getProducts() : void {
ro.getProducts();
}
private function handleGetProdudctResult(event:ResultEvent) : void {
}
private function handleUpdateProdudctResult(event:ResultEvent) : void {
}
private function handleFault(event:FaultEvent) : void {
Alert.show(event.fault.faultString);
}
</mx:Script>
<mx:RemoteObject id="ro" destination="tutorial-product" showBusyCursor="true">
<mx:method name="getProducts" fault="handleFault(event)"
result="handleGetProductsResult(event)" />
<mx:method name="updateProduct" fault="handleFault(event)"
result="handleUpdateProductResult(event)" />
</mx:RemoteObject>
<mx:Button label=“Get Products” click=“getProduct()” />
http://localhost:8400/samples/blazeds-debug/Census.html

19. Remoting
19
remoting-config.xml
<destination id="tutorial-product">
<properties>
<source>tutorial.ProductDAO</source>
</properties>
</destination>
Java Class Java Class
package tutorial; package tutorial;
public class ProductDAO { public class Product {
public List<Product> getProducts() { private int productId;
// DB logic private String name;
} private double price;
private int qty;
public void updateProduct(Product prod){
// DB logic // getters and setters for
} // above member variables
} }

20. Remoting
20
<mx:Script>
[Bindable]
private var products:ArrayCollection
private function handleGetProductsResult(event:ResultEvent) : void {
products = event.result as ArrayCollection;
}
private function handleFault(event:FaultEvent) : void {
Alert.show(event.toString());
}
</mx:Script>
<mx:DataGrid dataProvider="{products}" width="100%" height="100%" id="dg" >
<mx:columns>
<mx:DataGridColumn headerText="Serial Number" dataField="productId" />
<mx:DataGridColumn headerText="Name" dataField="name" />
<mx:DataGridColumn headerText="Price" dataField="price" />
<mx:DataGridColumn headerText="Quantity" dataField="qty" />
</mx:columns>
</mx:DataGrid>

21. Remoting
21
 Destination scope
 request – server creates an instance of Java class per
request (Default)
 application – one instance for entire application
 session - one instance per session
<destination id="tutorial-product">
<properties>
<source>tutorial.ProductDAO</source>
<scope>request</scope>
</properties>
</destination>

22. Remoting
22
 Concurrency
 multiple – existing requests are not canceled
 Single – one at a time
 last – latest request cancels any existing request
<mx:RemoteObject id="ro" destination="tutorial-product"
showBusyCursor="true">
<mx:method name="getProducts" fault="handleFault(event)"
result="handleGetProductsResult(event)"
concurrency=“multiple”/>
</mx:RemoteObject>

23. Data Serialization
23
Servlet Container
AS Java
BlazeDS
AS Java Your Application

24. Data Serialization
24
 Serializing Between ActionScript & Java
AS Type Java
Array(dense) java.util.List
Array(sparse) java.util.Map
Boolean java.lang.Boolean
Date java.util.Date
int/uint java.lang.Integer
Object java.util.Map
Typed Object Typed Object [RemoteClass]
XML org.w3c.dom.Document
• Dense array – all numeric indexes are consecutive (no gap)
• Sparse – gap between numeric indexes

25. Remoting
25
 AS Serialization Rule
 Public bean properties w/ getter/setter methods
 Public variables
 Private properties, constants are not serialized
 Client side
 Use [RemoteClass(alias=“ “)] to map directly to Java object
 Custom Serialization
package {
 Iexternallizable interface [Bindable]
[RemoteClass(alias="tutorial.Product")]
 [Transient] public class Product {
public var productId:int;
public var name:String;
public var price:Number;
public var qty:int;
}
}

26. Remoting
26
java.util.ArrayList
ActionScript ActionScript
Array java.util.TreeSet
ArrayCollection
java.util.TreeSet
public class ProductService {
public void addProduct(java.util.Set products) {}
public void addProduct(java.util.SortedSet products) {}
public void addProduct(java.util.List products) {}
}

27. Messaging
27
 Publish-subscribe messaging
 Among multiple Flex clients
 Support bridging to JMS topics (only)
 Server can push message to client on its own.
Consumer
Message
Producer
Messaging Consumer
Service

28. Messaging
28
BlazeDS Server Architecture
Message
MessageBrokerServlet Broker Service Destination Adapter
R MessageService MessageDestination
• Producer
O
• Consumer U ActionScript
Adapter
T
E
JMS
M Adapter
S
G Custom
Adapter

29. Messaging
29
messaging-config.xml
<destination id=’chat’>
<channels>
<channel ref=‘sample-amf’>
</channels>
</destination>
<mx:Application>
<mx:Script>
private function sendMessage(): void {
var msg = new AsyncMesage();
msg.body = “Hello there”
producer.send(msg);
}
private function handler(event:MessageEvent) : void {
Alert.show(“Got it: “ + event.message.body;
}
</mx:Script>
<mx:Producer id=“producer” destination=“chat”>
<mx:Consumer id=“consumer” destination=“chat”
message=“handler(event)”>
</mx:Application>

30. Messaging
30
 Message filtering
 Through message header and subtopic information
 Subscriber defines the filter criteria
 Send to server during the subscripting step
 Message filtering is done on the server
<mx:Application>
<mx:Script>
private function sendMessage(): void { <mx:Application>
var msg = new AsyncMesage(); <mx:Script>
msg.headers = new Array(); …
msg.headers[“user”]= “John”; </mx:script>
msg.body = “Hello there”; <mx:Consumer id=“consumer”
producer.send(msg); destination=“chat”
} message=“handler(event)”
</mx:script> selector=“user = ‘John’”>
… </mx:Application>
</mx:Application>

31. Messaging
31
 Filtering through subtopic
 Usesubtopic property of AsyncMessage
 Support single-token wildcard in subtopic string
<mx:Application>
<mx:Script>
private function sendMessage(): void {
var msg = new AsyncMesage();
msg.body = “Hello there”;
producer.subtopic = “chat.gossip”;
producer.send(msg); <mx:Application>
} <mx:Script>
</mx:script> …
<mx:Producer id=“producer” </mx:script>
destination=“chat”> <mx:Consumer id=“consumer”
… destination=“chat”
</mx:Application> message=“handler(event)”
subtopic=“chat.gossip”>
</mx:Application>

32. Messaging
32
Enable destination to support subtopic
<destination id=“chat” >
<properties>
<server>
<allow-subtopics>true</allow-subtopics>
<subtopic-separator>.</subtopic-separator>
</properties>
<channels>
<channel ref=‘sample-amf’>
</channels>
</destination>

33. Messaging
33
Performance related settings
Property Description
throttle-inbound Control # of inbound messages per second
throttle-outbound Control # of outbound messages per second
message-time-to-live How long server should keep a message pending
delivery before being discarded as undeliverable
Additional settings for security

34. Messaging
34
 Measuring message processing performance
 Message size
 Sever processing time
 Network travel time
 Message waiting time
 Ensure clients & server clocks are synchronized
 Enable at the channel level

35. Messaging
35
<channel-definition id="my-streaming-amf”
class="mx.messaging.channels.StreamingAMFChannel">
<endpoint
url="http://{server.name}:{server.port}/{context.root}/
messagebroker/streamingamf”
class="flex.messaging.endpoints.StreamingAMFEndpoint"/>
<properties>
<record-message-times>true</record-message-times>
<record-message-sizes>true</record-message-sizes>
</properties>
</channel-definition>

36. Messaging
36
 Use MessagePerformanceUtils to access processing
metrics
private function messageHandler(message:IMessage):void {
log.text += message.headers["user"] + ": " +
message.body.chatMessage + "n";
var perfInfo:MessagePerformanceUtils = new
MessagePerformanceUtils(message);
Alert.show(perfInfo.prettyPrint());
}

37. Proxy
37
google.com
Servlet Container
BlazeDS yahoo.com
Your
Application
amazon.com

38. Proxy
38
 HTTPService
 REST functionality
 All HTTP method
 PUT, DELETE, HEAD, POST, GET
 Get response data when status code != 200
 URL alias control on server side
<mx:HTTPService destination="CNNFeed" useProxy="true" id="topNewService"
resultFormat="e4x” result="handleTopNewResult(event)"/>
<!– using default proxy destination 
<mx:HTTPService useProxy="true" id="searchService" resultFormat="e4x”
result="handleSearchResult(event)” />

39. Proxy
39
 Proxy-config.xml
 Server side configuration
<destination id="DefaultHTTP">
<properties>
<dynamic-url>http://*</dynamic-url>
</properties>
</destination>
<destination id="CNNFeed">
<properties>
<url>http://rss.cnn.com/rss/cnn_topstories.rss</url>
</properties>
</destination>

40. Resources
40
 BlazeDS
 http://opensource.adobe.com/wiki/display/blazeds/Overview
 AMF Benchmark
 http://www.jamesward.com/census
 Architecting RIAs with Flex Data Management Services
 http://www.adobe.com/devnet/flex/articles/architecting_rias.html