Activity - demoExternalInput

Activity Type: Example

Description

This activity demonstrates the use of an external input. An input stream is created, a number of integer blocks that will be written to the stream is specified, the activity sums these and outputs the total.

The activity has one dynamically generated input upon which a specific number of integer blocks are received and summed. The activity has one output - the sum of the values of each block.

Example

<demoExternalInput name="externalInput">
  <nInputBlocks value="4"/>
  <streamName value="input"/>
  <myOutput name="output"/>
</demoExternalInput>

Specification

Element demoExternalInput:

• Attribute name - unique name for the activity within the scope of a request.
• nInputBlocks (required) - number of input blocks to be summed by this activity.
  • Attribute value - number of input blocks.
• streamName (required) - name of the external input stream to create.
  • Attribute value - name of the input stream.
• myOutput (required) - output stream on which the sum of the blocks will be output.
  • Attribute name - name of the activity's output stream.

Input and Output Types

• Inputs: none
• Output: myOutput - java.lang.String containing the sum of the integers received on the external input stream.

Data Resource Accessor

This activity can operate with any data resource accessor.

XML Schema

OGSA-DAI/schema/ogsadai/xsd/activities/demo_external_input.xsd

Class

uk.org.ogsadai.activity.examples.DemoExternalInputActivity

Client Toolkit Class

uk.org.ogsadai.client.toolkit.activity.examples.DemoExternalInput