Processor Chains and the Pipeline Manager

Processor 就是一个执行一些功能和返回状态码的一个组件，状态码决定chain中下一个是哪一个processor被执行。

 

PipelineManager 可以使你动态的添加或删除processor.Pipeline要执行processor。需要调用runProcess().他首先会找请求的链，如果is enable,PipelineManager 调用runProcess()，如果isn't enable,就会抛出一个异常。

 

The following sections describe how to create a processor pipeline：

 

配置Pipeline Manager:

每一个processor chain 都是有pipeline manager 控制的，它位于/atg/commerce/

PipelineManager. The PipelineManager属性：

$class=atg.commerce.pipeline.CommercePipelineManager

# The location of the XML configuration file in the classpath.
# Default: /atg/commerce/CommercePipeline.xml
definitionFile=/atg/commerce/commercepipeline.xml


# The transaction manager that the PipelineManager will use to coordinate its
# transactions.
transactionManager=/atg/dynamo/transaction/TransactionManager

# The amount of time in milliseconds that a thread will wait to execute a pipeline.
# Default: 15000 msec
chainLockWaitTimeout=15000

#
# The schedule to reinitialize the PipelineManager.
#
scheduler=/atg/dynamo/service/Scheduler
schedule=every 6 hours in 6 hours

 definitionFile是定义processor chains的。

 

Creating Processors：

首先要实现atg.service.pipeline.PipelineProcessor interface。

 

public abstract interface PipelineProcessor
{
  public static final String CLASS_VERSION = "$Id: //product/DAS/version/10.2/Java/atg/service/pipeline/PipelineProcessor.java#2 $$Change: 768621 $";
  public static final int STOP_CHAIN_EXECUTION_AND_COMMIT = 0;
  public static final int STOP_CHAIN_EXECUTION = 0;
  public static final int STOP_CHAIN_EXECUTION_AND_ROLLBACK = -1;
  
  public abstract int runProcess(Object paramObject, PipelineResult paramPipelineResult)
    throws Exception;
  
  public abstract int[] getRetCodes();
}

 

public abstract class ProcProcessPaymentGroup extends GenericService
  implements PipelineProcessor
{
  public static String CLASS_VERSION = "$Id: //product/DCS/version/10.2/Java/atg/commerce/payment/processor/ProcProcessPaymentGroup.java#2 $$Change: 768796 $";
  public static final int SUCCESS = 1;

  protected void invokeProcessorAction(PaymentManagerAction pProcessorAction, PaymentManagerPipelineArgs pParams)
    throws CommerceException
  {
    PaymentStatus status = null;

    if (isLoggingDebug()) {
      logDebug("Obtained processorAction with: " + pProcessorAction);
    }
    if (pProcessorAction == PaymentManagerAction.AUTHORIZE)
      status = authorizePaymentGroup(pParams);
    else if (pProcessorAction == PaymentManagerAction.DEBIT)
      status = debitPaymentGroup(pParams);
    else if (pProcessorAction == PaymentManagerAction.CREDIT)
      status = creditPaymentGroup(pParams);
    else if (pProcessorAction == PaymentManagerAction.DECREASE_AUTH_AMT)
      status = decreaseAuthorizationForPaymentGroup(pParams);
    else {
      throw new CommerceException("Invalid processor action specified: " + pProcessorAction);
    }
    pParams.setPaymentStatus(status);
  }

  public PaymentStatus decreaseAuthorizationForPaymentGroup(PaymentManagerPipelineArgs pParams)
    throws CommerceException
  {
    return null;
  }

  public abstract PaymentStatus authorizePaymentGroup(PaymentManagerPipelineArgs paramPaymentManagerPipelineArgs)
    throws CommerceException;

  public abstract PaymentStatus debitPaymentGroup(PaymentManagerPipelineArgs paramPaymentManagerPipelineArgs)
    throws CommerceException;

  public abstract PaymentStatus creditPaymentGroup(PaymentManagerPipelineArgs paramPaymentManagerPipelineArgs)
    throws CommerceException;

  public int runProcess(Object pParam, PipelineResult pResult)
    throws Exception
  {
    PaymentManagerPipelineArgs params = (PaymentManagerPipelineArgs)pParam;
    PaymentManagerAction action = params.getAction();
    try {
      invokeProcessorAction(action, params);
    }
    catch (CommerceException e) {
      logError(e);
      pResult.addError("ProcProcessPaymentGroupFailed", e);
      return 0;
    }

    return 1;
  }

  public int[] getRetCodes()
  {
    int[] retCodes = { 1 };
    return retCodes;
  }
}

 Pipeline Definition Files:

PipelineManager:定义文件根节点

pipelinechain： 定义一个procesor chain

• name：名字
• transaction：processor默认使用的事物模式
• headlink:在processor chain中的第一个processor被执行
• classname:将被实例化和用于PipelineChain对象，默认是atg.service.pipeline.PipelineChain.而且一定是他的子类
• resultclassname:用于pipleineResult对象，The default is atg.service.pipeline.PipelineResult. The value must implement PipelineResult.

pipelinelink:在 processor chain中定义processor.

• name：processor的名字
• transaction

processor：The name of the PipelineProcessor object.

1. jndi ：所引用processor类，这个对象是通过JNDI来解决的e

transition：根绝返回值决定下一个将要被执行的引用

1. returnvalue：An integer string that is used to define the next pipeline element.
2. 下一个将会被执行的pipelineprocessor,如果当前的返回值匹配return value

<?xml version="1.0"?>
<!DOCTYPE PipelineManager SYSTEM "PipelineManager.dtd">
<PipelineManager>
<pipelinechain name="AddToCart" transaction="TX_REQUIRED" headlink="proc1">
<pipelinelink name="proc1">
<processor class="atg.commerce.addA"/>
<transition returnvalue="1" link="proc2"/>
<transition returnvalue="2" link="proc3"/>
</pipelinelink>
<pipelinelink name="proc2" transaction="TX_REQUIRES_NEW">
<processor class="atg.commerce.addB"/>
<transition returnvalue="1" link="proc4"/>
<transition returnvalue="2" link="proc5"/>
</pipelinelink>
<pipelinelink name="proc3">
<processor class="atg.commerce.addE"/>
<transition returnvalue="1" link="proc6"/>
<transition returnvalue="2" link="proc7"/>
<transition returnvalue="3" link="proc2"/>
</pipelinelink>
<pipelinelink name="proc4">
<processor class="atg.commerce.addC"/>
</pipelinelink>
<pipelinelink name="proc5" transaction="TX_REQUIRES_NEW">
<processor class="atg.commerce.addD"/>
</pipelinelink>
<pipelinelink name="proc6" transaction="TX_NOT_SUPPORTED">
<processor class="atg.commerce.addF"/>
</pipelinelink>
<pipelinelink name="proc7" transaction="TX_SUPPORTS">
<processor jndi="/dynamo/atg/commerce/addG"/>
</pipelinelink>
</pipelinechain>
<pipelinechain name="RemoveFromCart" transaction="TX_REQUIRED"
headlink="proc99" classname="atg.service.pipeline.PipelineMonoChain">
<pipelinelink name="proc99">
<processor class="atg.commerce.removeA"/>
</pipelinelink>
</pipelinechain>
</PipelineManager>