一个基于Mule的企业服务总线的案例

原文地址： http://www.theserverside.com/tt/articles/article.tss?l=CaseStudyMule

面向服务架构的关键字之一就是ESB。以前很多厂商靠买消息服务器来提供集成交互的方案，然后出现了SOAP和REST。

早期的尝试基本上都是通过定一个固定的消息格式，例如xml来让各个系统交换。但是这些消息格式本身经常需要修订，就给集成带来了很大的麻烦。

最好的解决方案就是每个应用还是用自己支持的接口，例如EDI或者SOAP，然后构建一个可以集成各种结构的聚合器，每一个应用的接口就开发成聚合器的一个端口。这样一个cobol写的应用就可以和一个j2me的应用交互，而不需要知道彼此的技术细节。

常见ESB供应商比较

 

Product	Vendor	Connects with...
Matrix BusinessWorks	TIBCO	SOAP, EMS, JMS, Rendezvous, MQ, BPEL
Mule ESB	Open-source, MuleSource, Inc.	SOAP, REST, JMS, MQ, JBI, AQ, Caching, JavaSpaces, GigaSpaces, Email, IM, JCA, AS400 Data Queues, System I/O.
OpenESB	Open-source, Sun Microsystems	JBI, JCA, JAX-RPC, JAX-WS
Sonic ESB	Progress Software	JMS, SOAP, JMX
Websphere ESB	IBM	JMS, MQ, SOAP; requires additional adapters to interface with other products and legacy protocols; requires Websphere to work

这里少了一个ServiceMix。

下面是这个案例的细节：

本案例用到的程序包括：

AMD-based 2.6 GHz 4 GB RAM, and Intel-based 3 GHz 4 GB RAM servers

Solaris 10 and Ubuntu Linux Dapper Drake

Java Run-time Environment 1.5.9

Mule current general availability package

A commercial JMS provider

Commercial applications for order capture, inventory management, order management, fulfillment, and reporting

假设有一个项目要集成很多企业级应用程序，出于开发周期的压力，我们选择集成而非重新构建的策略。也就是说order capture, inventory management, order management, fulfillment, and reporting 这些都购买现成的厂商的，我们只需要集中开发一个内容管理系统。

通过和其它六家厂商的协商，他们都提供了JMS和SOAP的接口。因此我们需要一个专业的JMS服务器。

下面我们来看看配置文件：

 

< mule-configuration  id ="Enterprise-Applications-Mashup"  version ="1.0" >  

首先定义一个Mule和JMS交互的连接器，相当于一个连接池
   < connector  name ="jmsConnector"  className ="org.mule.providers.jms.JmsConnector" >  
     < properties >  
       < property  name ="jndiProviderUrl"
                value ="bitjmsnaming://172.28.63.209:7222" />  
       < property  name ="connectionFactoryJndiName"
                value ="QueueConnectionFactory" />  
       < map  name ="jndiProviderProperties" >  
         < property  name ="java.naming.factory.initial"
                  value ="com.bitco.bitjms.naming.bitjmsInitialContextFactory" />  
         < property  name ="java.naming.security.principal"  value ="admin" />  
         < property  name ="java.naming.security.credentials"  value ="" />  
       </ map >  
       < property  name ="username"  value ="admin" />  
       < property  name ="password"  value ="" />  
     </ properties >  
   </ connector >  
   然后定义一些端点，每个端点都是一个外部供应商程序的接口
   < global-endpoints >  
     < endpoint  name ="inJMSGTA"        address ="jms://q.gta.in"  connector ="jmsConnector" />  
     < endpoint  name ="inJMSSeebelle"   address ="jms://q.seebelle.in"  connector ="jmsConnector" />  
     < endpoint  name ="inJMSYenta"      address ="jms://q.yenta.in"  connector ="jmsConnector" />  
     < endpoint  name ="inJMSCatwire"    address ="jms://q.catwire.in"  connector ="jmsConnector" />  
     < endpoint  name ="inJMSBitco"      address ="jms://q.bitco.in"  connector ="jmsConnector" />  
     < endpoint  name ="outJMSGTA"       address ="jms://q.gta.out"  connector ="jmsConnector" />  
     < endpoint  name ="outJMSSeebelle"  address ="jms://q.seebelle.out"  connector ="jmsConnector" />  
     < endpoint  name ="outJMSYenta"     address ="jms://q.yenta.out"  connector ="jmsConnector" />  
     < endpoint  name ="outJMSCatwire"   address ="jms://q.catwire.out"  connector ="jmsConnector" />  
     < endpoint  name ="outJMSBitco"     address ="jms://q.bitco.out"  connector ="jmsConnector" />  
     < endpoint  name ="console"         address ="stream://System.out"   />  
   </ global-endpoints >  

   < transformers >  
     < transformer  name ="JMSMessageToObject"
                 className ="org.mule.providers.jms.transformers.JMSMessageToObject"   />  
     < transformer  name ="ObjectToString"
                 className ="org.mule.transformers.simple.ObjectToString"   />  
   </ transformers >  

   < model  name ="Enterprise-Applications-Mashup-JMS" >  
     < mule-descriptor  name ="JMSMessageSwitchboard"
     implementation ="org.mule.components.simple.PassThroughComponent" >  
系统只有一个inbound，也就是进入系统消息的定义，端口名称叫做outJMSBitco，也就是说outJMSBitco发出一个指令，进入总线，然后Mule把这个消息转换后发送给其它所有的outbound-router，离开总线，进入别的应用程序。
       < inbound-router >  
         < global-endpoint  name ="outJMSBitco" />  
       </ inbound-router >  

       < outbound-router  match-all ="true" >  
         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"
                  expression ="OrderHistoryRequest"   />  
         </ router >              

以下面这条为例：
这条路由的意思是，将消息通过JMS发送给Siebel，JMS的头要标上OrderHistoryResonse，这样Siebel的消息队列受到一条这个消息，Siebel知道对方要做什么操作，将OrderHistory查询出来。
         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSSiebel"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"
                  expression ="OrderHistoryResponse"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSCatwire" />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="item"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSCatwire" />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="item_mapping"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta" />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="PAMInventoryUpdate"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSGTA"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="CustomerSearchRequest"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSSiebel"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="CustomerSearchResponse"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="OrderDetailsRequest"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSSiebel"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="OrderDetailsResponse"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="OrderAddUpdRequest"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSSiebel"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="OrderAddUpdResponse"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="catwireCreateItem"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSGTA"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="catalogupdate"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSGTA"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="productupdate"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSGTA"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="skuupdate"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="gtaCreateOrder"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSYenta"   />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="gtaGetOrderDetails"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="openJmsOutbound" />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="XXXOrderUpdate"   />  
         </ router >              

         < router  className ="org.mule.routing.outbound.FilteringOutboundRouter" >  
           < global-endpoint  name ="inJMSBitco" />  
           < filter  className ="org.mule.samples.jms.JMSHeaderFilter"  expression ="OrderRelease"   />  
         </ router >              
这个端口的意思是把消息打印在DOS窗口上
         < router  className ="org.mule.routing.outbound.OutboundPassThroughRouter" >  
           < endpoint  address ="stream://System.out"  transformers ="ObjectToString"   />  
         </ router >  
       </ outbound-router >  
     </ mule-descriptor >  
   </ model >  
</ mule-configuration >