TuscanySCA6-SCA装配模型

1. Component, service, reference and property naming conventions

    SCA规范名没有定义它们的命名规范，下面只是推荐的命名格式：
    (1) Component,Service以大写字母开头，驼峰式命名；

    (2) Reference,property默认以小写字母开头。

2. 组合定义文件
    组合是被用来定义服务、组件和引用的容器。 它被用来将SCA制品装配成逻辑分组的组件。SCA 组合可粗略的认

    为是和Spring中通常被称作应用程序上下文（application context）的XMl文件类似的东西，而component元

    素，则和Spring配置文件中定义的bean元素在功能上类似。
    SCA组合装配XML示例，problemMgmt.composite.xml：
    <?xml version="1.0" encoding="ISO-8859-15"?>
    <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
              xmlns:hw="http://opensoa.book.chapter3" name="ProblemManagementComposite"
              targetNamespace="http://opensoa.book.chapter3">
       <service name="ProblemTicketComponent" promote="ProblemTicketComponent">
          <binding.ws uri="http://localhost:8085/ProblemTicketService"/>
       </service>
       <component name="ProblemTicketComponent">
          <implementation.java class="opensoa.book.chapter3.impl.ProblemTicketComponentImpl"/>
          <reference name="createTicket" target="CreateTicketComponent"/>
       </component>
       <component name="CreateTicketComponent">
           <implementation.java class="opensoa.book.chapter3.impl.CreateTicketComponentImpl"/>
       </component>
     </composite>

     启动该装配集的方式：

     SCADomain scaDomain = SCADomain.newInstance("problemMgmt.composite");

3. 配置组件

    组件指的是通过代码表达的业务功能，是应用程序构建的单元；组件既可以提供服务，也可以使用服务。

    ProblemTicketComponentImpl的Java实现：

    @Service(ProblemTicketComponent.class)               
    public class ProblemTicketComponentImpl implements ProblemTicketComponent {

          private CreateTicketComponent createTicket;               

          public int createTicket(TicketDO ticket) {

               System.out.println(ticket.toString());
               return createTicket.create(ticket);
          }

          @Reference                               
          public void setCreateTicket( CreateTicketComponent createTicket) {
               this.createTicket = createTicket;
          }
    }

 

    @Remotable
    public interface ProblemTicketComponent {
         public int createTicket(TicketDO ticket);
    }

 

    public class CreateTicketComponentImpl implements CreateTicketComponent {

         public int create(TicketDO ticket) {
              Random r = new Random();

              return r.nextInt(300000);

         }

    }

4. 定义服务

    通过接口类定义的方法签名或interface.wsdl来规定哪些操作被允许，这种做法在容器级别会得到强制保障，是

    安全的；而简单的创建 一个自定义的、只包含哪些你想暴露的操作的WSDL的做法，是不安全的，因为知道源码

    的人还是可以调用哪些没有被显示暴露出来的操作。

    <service name="ProblemTicketComponent" promote="ProblemTicketComponent">
        <interface.java
         interface="opensoa.book.chapter3_23.ProblemTicketComponent" />
       
        <binding.ws uri="http://localhost:8085/ProblemTicketService" />
    </service>

5. 使用属性

    <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
          targetNamespace="http://opensoa.book.chapter3"
          xmlns:hw="http://opensoa.book.chapter3"
          name="ProblemManagementComposite">

          <!-- VARIANT 1
          <property name="username">[e-mail]</property>
          <property name="password">mypassword1</property>
          -->
   
          <!-- VARIANT 2 -->
          <property name="credentials" type="hw:CredentialsType">
               <Credentials>
                     <username>[e-mail]</username>
                     <password>mypassword1</password>
               </Credentials>
          </property>
   
          <service name="ProblemTicketComponent"  promote="ProblemTicketComponent">
               <binding.ws uri="http://localhost:8085/ProblemTicketService" />
          </service>

          <component name="ProblemTicketComponent">
                <implementation.java
                        class="opensoa.book.chapter3_24.impl.ProblemTicketComponentImpl" />

                <!-- use w/VARIANT 1
                        <property name="username" source="$username" />
                        <property name="password" source="$password" />
                -->
       
                <!--  use w/VARIANT 2 -->
                 <property name="username" source="$credentials/*[local-name()='Credentials']/
                          *[local-name()='username']" />
                 <property name="password" source="$credentials/*[local-name()='Credentials']/
                          *[local-name()='password']" />
   
                 <reference name="createTicket" target="CreateTicketComponent" />
           </component>

           <component name="CreateTicketComponent">
                   <implementation.java
                         class="opensoa.book.chapter3_24.impl.CreateTicketComponentImpl" />
           </component>

     </composite>

 

     @Service(ProblemTicketComponent.class)                
     public class ProblemTicketComponentImpl implements ProblemTicketComponent {

         /*第一种使用方式*/
         @Property
         protected String username;
         @Property
         protected String password;

 

         /* 另一种使用方式 */

         protected String username;

         @Property(name="username")

         public void setMyUserName(String username){

                this.username = username

         }
      
         private CreateTicketComponent createTicket;               

         public int createTicket(TicketDO ticket) {
               System.out.println(ticket.toString());
     
               /* username variable passed as injected property value */
               System.out.println("username is: " + username);
     
               return createTicket.create(ticket);
         }

         /* Note, instead of using a setter, you could inject the reference
          * directly at the variable reference level, similar to what
          * is done for the propery injections shown above.
          */
         @Reference                               
         public void setCreateTicket(CreateTicketComponent createTicket) {
               this.createTicket = createTicket;
         }
    }

6. 实现选项

    Apache Tuscany 的SCA实现类型：

    Java组件，Spring程序集，脚本：JS,Groovy，Ruby,Pythin,XSLT,BPEL,XQuery,OSGi

    实现组示例：

    <?xml version="1.0" encoding="ISO-8859-15"?>
    <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
           xmlns:hw="http://opensoa.book.chapter325"
           name="IssueManagementComposite"
           targetNamespace="http://opensoa.book.chapter325">
   
          <service name="SystemErrorService" promote="SystemErrorComponent">
                    <binding.ws uri="http://localhost:8085/SystemErrorService"/>
          </service>
 
          <component name="SystemErrorComponent">
                <implementation.java  

                          class="opensoa.book.chapter3_25.impl.SystemErrorComponentImpl"/>
                <reference name="problemTicket" target="ProblemTicket"/>
          </component>
 
          <component name="ProblemTicket">
                  <implementation.composite name="hw:ProblemManagementComposite"/>
          </component>
      </composite>

 

      实现类：

      @Service(SystemErrorComponent.class)
      public class SystemErrorComponentImpl implements  SystemErrorComponent {

             @Reference
             public ProblemTicketComponent problemTicket;

             public int systemProblem(String system, String title,String problem) {
                   System.out.println("*** SystemErrorComponentImpl ***");
                   int rval = 0;
     
                   TicketDO ticket = new TicketDO();
                   ticket.setSubject(title);
                   ticket.setSubject(problem);
                   ticket.setSource(system);

                   rval = problemTicket.createTicket(ticket);
     
                   System.out.println("problemTicket:" + rval);
     
                   return rval;
            }
      }

7. 使用引用进行依赖注入

    <composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
         targetNamespace="http://opensoa.book.chapter3"
         xmlns:hw="http://opensoa.book.chapter3"
         name="IssueManagementComposite">

         <service name="SystemErrorService" promote="SystemErrorComponent">
               <binding.ws uri="http://localhost:8085/SystemErrorService" />
         </service>

         <component name="SystemErrorComponent">
              <implementation.java
                    class="opensoa.book.chapter3_26.impl.SystemErrorComponentImpl" />
         </component>

         <reference name="ProblemTicket" promote="SystemErrorComponent/problemTicket">
                   <binding.ws uri="http://localhost:8086/ProblemTicketService" />
         </reference>
     </composite>

 

     @Reference
      public void setProblemTicket(ProblemTicketComponent problemTicket) {
            this.problemTicket = problemTicket;
      }

8. 定义可用的绑定

    Apache Tuscany的绑定类型：

    WebService， JMs,  JSON-RPC，EJB,  Feed

    将多个Web服务合并到单个WSDL文件中：

    <composite
          xmlns="http://www.osoa.org/xmlns/sca/1.0"
          targetNamespace="http://opensoa.book.chapter327"
          xmlns:hw="http://opensoa.book.chapter327"
          name="IssueManagementComposite">

          <service  name="SystemErrorService" promote="SystemErrorComponent">

          <binding.ws   wsdlElement="http://chapter327.book.opensoa#wsdl.binding(

              SystemErrorServiceJMSBinding)"     

              uri="jms:/SystemErrorInQueue?transport.jms

              .ConnectionFactoryJNDIName=QueueConnectionFactory

              &amp;java.naming.factory.initial=org.apache.activemq

              .jndi.ActiveMQInitialContextFactory&amp;java.naming.provider.url

              =tcp://localhost:61616?wireFormat.maxInactivityDuration=0" />

          <binding.ws
          wsdlElement="http://chapter327.book.opensoa#wsdl.port(SystemErrorService/SOAP)" />

          <!--
          <binding.ws uri="http://localhost:8085/SystemErrorService" />
          -->
          </service>

          <component name="SystemErrorComponent">
                 <implementation.java
                       class="opensoa.book.chapter3_27.impl.SystemErrorComponentImpl" />
        
          <reference   name="problemTicket"     target="ProblemTicket" /></component>

          <component name="ProblemTicket">
                <implementation.composite name="hw:ProblemManagementComposite" />
          </component>  
    </composite>

    SCA与远程协议(如：Web Service)之间的不同：

    SCa定义可入如何将网络服务装配成可用的应用程序，并且提供了一种语言用于描述这种装配；而Web Service

    描述了怎样使用协议去调用单个的服务。