Solution :
During the installation of SOA Suite, , If the path location for Disk4,Stage location is wrong or any issues during instllation, then the Oracle SOA Common Adapters - 11.1.1.0 jar file is not copied properly.
Installation log is found :
C:\Program Files\Oracle\Inventory\logs\install2012-09-22_02-19-54AM
Either you can copy the required jar files or Uninstall soa suite and reinstall.
It worked for me. problem resolved.