flex与java通信：blazeds配置文件

一、web.xml中对blazeds的配置

<listener>
		<listener-class>flex.messaging.HttpFlexSession</listener-class>
	</listener>

<listener>用于将HttpFlexSession类作为监听器注册到web.xml中,这样系统就可以检测到J2EE HttpSession属性和代理属性的变化,进而通知FlexSession属性和目前绑定的listener做相应处理.

<servlet>
		<servlet-name>MessageBrokerServlet</servlet-name>
		<servlet-class>flex.messaging.MessageBrokerServlet</servlet-class>
		<init-param>
			<param-name>services.configuration.file</param-name>
			<param-value>/WEB-INF/flex/services-config.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>MessageBrokerServlet</servlet-name>
		<url-pattern>/messagebroker/*</url-pattern>
	</servlet-mapping>

其实现是基于一个叫flex.messaging.MessageBroker的Servlet。各种消息通道的配置都存在于WEB-INF\flex\services-config.xml及其包含的3个XML文件中。

MessageBrokerServlet的Servlet将负责对对所有URL符合/messagebroker/*模式的请求进行处理,它会在Servlet容器启动时启动,并在启动时读取配置文件/WEB-INF/flex/services-config.xml.

<login-config>
		<auth-method>BASIC</auth-method>
	</login-config>

1、service-config.xml

services-config.xml包含BlazedDS引用的服务文件,安全设置,通道定义,系统参数.

----------services

<services>
  
  <service class="flex.samples.DatabaseCheckService" id="hsqldb" />
  <service-include file-path="remoting-config.xml" />
  <service-include file-path="proxy-config.xml" />
  <service-include file-path="messaging-config.xml" />
  
	<service class="flex.samples.runtimeconfig.EmployeeRuntimeRemotingDestination" id="runtime-employee-ro" />

 	<!-- 
 	Application level default channels. Application level default channels are 
 	necessary when a dynamic destination is being used by a service component
 	and no ChannelSet has been defined for the service component. In that case,
 	application level default channels will be used to contact the destination.
  -->
  <default-channels>
  <channel ref="my-amf"/>
  </default-channels>
 
	</services>

----------remoting-config.xml配置的就是一个flex.messaging.services.RemotingService

<service id="remoting-service"
 class="flex.messaging.services.RemotingService"></service>

remoting-service的内容：

<adapters>
  <adapter-definition id="java-object" class="flex.messaging.services.remoting.adapters.JavaAdapter" default="true"/>
 </adapters>

 <default-channels>
  <channel ref="my-amf"/>
 </default-channels>

 <destination id="product">
  <properties>
<source>flex.samples.product.ProductService</source>
  </properties>
 </destination>
 ..............destinations

adapters为用户设置设配器

channel的ref属性表明引用了信息通道

destination设置服务终端的目的地

----------messaging-config.xml配置的就是一个flex.messaging.services.MessageService

<service id="message-service" class="flex.messaging.services.MessageService"></service>

messaging-service的内容：

<adapters>
  <!-- Blazeds提供了两种消息适配器，actionscript和jms --><adapter-definition id="actionscript" class="flex.messaging.services.messaging.adapters.ActionScriptAdapter" default="true" />
  <adapter-definition id="jms" class="flex.messaging.services.messaging.adapters.JMSAdapter"/>
 </adapters>
 
 <default-channels>
		<channel ref="my-streaming-amf"/>
		<channel ref="my-polling-amf"/>
 </default-channels>

 <destination id="market-data-feed">
  <properties>
<server>
 <allow-subtopics>true</allow-subtopics>
 <subtopic-separator>.</subtopic-separator>s
</server>
  </properties>
  <channels>
			<channel ref="my-polling-amf"/>
			<channel ref="my-streaming-amf"/>
<channel ref="per-client-qos-polling-amf"/>
  </channels>  
 </destination>..............destinations

jms消息适配器。消息先发送到消息服务器上，flex端订阅消息，如果服务器上有消息在客户端就显示出来。消息服务器很多都是收费的，开源的有ActiveMQ、OPENJMS等。ActiveMQ
是Apache的产品，最流行的，能力强劲的开源消息总线。ActiveMQ 是一个完全支持JMS1.1和J2EE 1.4规范的 JMS Provider实现,尽管JMS规范出台已经是很久的事情了,但是JMS在当今的J2EE应用中间仍然扮演着特殊的地位。blazeds的官方文档上的例子就是用的ActiveMQ作为消息服务器

其他：Blazeds的消息机制是采用不断的轮询实现的，因此性能不怎么好，并发数最大为100，LCDS的消息机制是采用java的NIO，最高并发数是1000，Blazeds和LCDS相比性能还是比较差的，不过***系统的用户数比较少的情况下，Blazeds还是可以的，毕竟，客户都是比较吝啬的，有免费的肯定不想掏钱买昂贵的LCDS。

这里将会进一步补充jms有关内容。

----------proxy-config.xml配置的就是一个flex.messaging.services.HTTPProxyService

<service id="proxy-service" class="flex.messaging.services.HTTPProxyService">
</service>

proxy-confige的内容：

 <properties>
  <connection-manager>
<max-total-connections>100</max-total-connections>
<default-max-connections-per-host>2</default-max-connections-per-host>
  </connection-manager>
  <allow-lax-ssl>true</allow-lax-ssl>
 </properties>

 <default-channels>
  <channel ref="my-http"/>
  <channel ref="my-amf"/>
 </default-channels>

 <adapters>
  <adapter-definition id="http-proxy" class="flex.messaging.services.http.HTTPProxyAdapter" default="true"/>
  <adapter-definition id="soap-proxy" class="flex.messaging.services.http.SOAPProxyAdapter"/>
 </adapters>

 <destination id="DefaultHTTP">
		<properties>
		</properties>
 </destination>
 
 <destination id="ws-catalog">
  <properties>
<wsdl>http://feeds.adobe.com/webservices/mxna2.cfc?wsdl</wsdl>
<soap>*</soap>
  </properties>
  <adapter ref="soap-proxy"/>
 </destination>	..............destinations

----------security

 <security>
  <security-constraint id="sample-users">
<auth-method>Custom</auth-method>
<roles>
 <role>sampleusers</role>
</roles>
  </security-constraint>

		<login-command class="flex.messaging.security.TomcatLoginCommand" server="Tomcat"/>  
  <!-- Uncomment the correct app server
  <login-command class="flex.messaging.security.TomcatLoginCommand" server="JBoss">
  <login-command class="flex.messaging.security.JRunLoginCommand" server="JRun"/>
  <login-command class="flex.messaging.security.WeblogicLoginCommand" server="Weblogic"/>
  <login-command class="flex.messaging.security.WebSphereLoginCommand" server="WebSphere"/>  
  -->
 </security>

security为配置安全性选项,然而,为remoting-config.xml或message-config.xml中的service添加安全性选项也是可以的.目的是只有通过身份验证,并具有某些role的用户才可以访问相应的destination.

security-constraint为安全约束.可以为destination应用安全约束.定义的方式有两种:一种是引用,一种是在destination定义的内部声明安全约束.

----------redeploy

  <redeploy>
<enabled>true</enabled>
<watch-interval>20</watch-interval>
<watch-file>{context.root}/WEB-INF/flex/services-config.xml</watch-file>
<watch-file>{context.root}/WEB-INF/flex/proxy-config.xml</watch-file>
<watch-file>{context.root}/WEB-INF/flex/remoting-config.xml</watch-file>
<watch-file>{context.root}/WEB-INF/flex/messaging-config.xml</watch-file>
<touch-file>{context.root}/WEB-INF/web.xml</touch-file>
  </redeploy>

----------logging

 <logging>
  <!-- You may also use flex.messaging.log.ServletLogTarget -->
  <target class="flex.messaging.log.ConsoleTarget" level="Error">
<properties>
 <prefix>[BlazeDS] </prefix>
 <includeDate>false</includeDate>
 <includeTime>false</includeTime>
 <includeLevel>true</includeLevel>
 <includeCategory>false</includeCategory>
</properties>
<filters>
 <pattern>Endpoint.*</pattern>
 <pattern>Service.*</pattern>
 <pattern>Configuration</pattern>
</filters>
  </target>
 </logging>

<target>为日志信息的目标,默认的目标是控制台输出,即System.out(Java).
若要使用Servlet日志文件作为目标,将class属性改为"flex.messaging.log.ServletLogTarget".
level="Error"为日志的记录级别.有None,Error,Warn,Info,Debug,All六种选择.

<properties>为日志信息的显示格式.包括信息前缀(prefix)以及是否包含时间(includeTime),日期(includeDate),级别(includeLevel)或者类别.

<filters>为信息的过滤条件,只有匹配的类别才会被记录到指定的目标中.

----------channels

	<channels>
  <channel-definition id="per-client-qos-polling-amf" class="mx.messaging.channels.AMFChannel">
<endpoint url="http://{server.name}:{server.port}/{context.root}/messagebroker/qosamfpolling" class="flex.messaging.endpoints.AMFEndpoint"/>
<properties>
 <polling-enabled>true</polling-enabled>
 <polling-interval-millis>500</polling-interval-millis>
 <flex-client-outbound-queue-processor class="flex.samples.qos.CustomDelayQueueProcessor">
  <properties>
<flush-delay>5000</flush-delay>
  </properties>
 </flex-client-outbound-queue-processor>
</properties>
  </channel-definition>
	...............
 </channels>

channel-definition定义了Channel的标识及其实现类

endpoint定义了endpoint的实现类和Channel和Endpoint通信的url

Channel的作用就是帮助我们传输消息.Channel使用URL与Endpoint通信.Endpoint就是消息传输的***,它并不真正处理消息,它将处理过程委托给service.这样就分离了协议和消息类型这两个正交的关注点.Endpoint在接收到消息时会根据消息的destination获得合适的service,然后调用service.service.Message方法处理消息.BlazeDS定义了RemotingService,HttpProxyService,MessageService三类service,分别处理前端RemoteObject,HTTPService和WebService等组件发起的请求