The following code shows the .bpel file that uses the flowN activity to look up information on an arbitrary number of hotels.

The following example shows the sequence name.

  <sequence name="main">
  <!-- Received input from requester. 
    Note: This maps to operation defined in NflowHotels.wsdl
    The requester sends a set of hotels names wrapped into the "inputVariable"
    -->

The following actions take place. A receive activity calls the client partner link to get the information that the flowN activity must define N times and look up the hotel information. The following provides an example:

    <receive name="receiveInput" partnerLink="client"
 portType="client:NflowHotels" operation="initiate" variable="inputVariable"
 createInstance="yes"/>
    <!-- 
       The 'count()' Xpath function is used to get the number of hotelName
       noded passed in.
       An intermediate variable called "NbParallelFlow" is
       used to store the number of N flows being executed
       -->
    <assign name="getHotelsN">
      <copy>
        <from 
expression="count($InputVariable.payload/client:HotelName);"/>
        <to variable="NbParallelFlow"/>
      </copy>
    </assign>
    <!-- Initiating the FlowN activity
        The N value is initialized with the value stored in the
 "NbParallelFlow" variable
        The variable call "Index" is defined as the index variable
        NOTE: Both "NbParallelFlow" and "Index" variables have to be declared
        -->

The flowN activity begins next. After defining a name for the activity of flowN, N is defined as a value from the inputVariable, which is the number of hotel entries. The activity also assigns index as the index variable. The following provides an example:

<bpelx:flowN name="FlowN" N="bpws:getVariableData('NbParallelFlow')
indexVariable="Index'>
      <sequence name="Sequence_1">
        <!-- Fetching each hotelName by indexing the "inputVariable" with the
 "Index" variable.
            Note the usage of the  "concat()" Xpath function to create the
 expression accessing the array element.
            -->

The copy rule shown in the following example then uses the index variable to concatenate the hotel entries into a list:

<assign name="setHotelId">
  <copy>
    <from expression=
"bpws:getVariableData('inputVariable','payload',concat('/client:Nflo
wHotelsProcessRequest/client:ListOfHotels/client:HotelName[',
bpws:getVariableData('Index'),']'))"/>
            <to variable="InvokeHotelDetailInputVariable" part="payload"
 query="/ns2:hotelInfoRequest/ns2:id"/>
          </copy>
        </assign>

Using the hotel information, an invoke activity looks up detailed information for each hotel through a web service. The following provides an example:

 <!-- For each hotel, invoke the web service giving detailed information
 on the hotel -->
        <invoke name="InvokeHotelDetail" partnerLink="getHotelDetail"
 portType="ns2:getHotelDetail" operation="process"
 inputVariable="InvokeHotelDetailInputVariable"
 outputVariable="InvokeHotelDetailOutputVariable"/>
      </sequence>
    </bpelx:flowN>

Finally, the BPEL process sends detailed information on each hotel to the client partner link. The following provides an example:

    <invoke name="callbackClient" partnerLink="client"
 portType="client:NflowHotelsCallback" operation="onResult"
 inputVariable="outputVariable"/>
  </sequence>
  </sequence>