You can test your Composite Application project by navigating to the c:\temp folder and creating a input.txt file.
Navigate to the c:\temp folder of your system.
Note that c:\temp was the designated polling directory for both Poll and Write operations when WSDL documents were created.
Create a .txt file and add some content to the file and rename it as input.txt.
Instantly the input.txt file is replaced by output.txt file.
The output.txt file retains the content of the input.txt file. That is, the content of input.txt is written to output.txt.