Here is the sample OIM API code for submitting request for Provision Application Instance:
public void submitProvisionRequest(RequestService requestService) throws InvalidRequestException, InvalidRequestDataException, RequestServiceException, BulkBeneficiariesAddException, BulkEntitiesAddException{
String beneficiaryKey = "141";
String applicationInstanceName = "ActiveDirectory";
String applicationInstanceKey = "14";
RequestData requestData = new RequestData();
Beneficiary beneficiary = new Beneficiary();
beneficiary.setBeneficiaryKey(beneficiaryKey);
beneficiary.setBeneficiaryType(Beneficiary.USER_BENEFICIARY);
RequestBeneficiaryEntity requestEntity = new RequestBeneficiaryEntity();
requestEntity.setRequestEntityType(OIMType.ApplicationInstance);
requestEntity.setEntitySubType(applicationInstanceName);
requestEntity.setEntityKey(applicationInstanceKey);
requestEntity.setOperation(RequestConstants.MODEL_PROVISION_APPLICATION_INSTANCE_OPERATION);
List targetEntities = new ArrayList();
targetEntities.add(requestEntity);
beneficiary.setTargetEntities(targetEntities);
List beneficiaries = new ArrayList();
beneficiaries.add(beneficiary);
requestData.setBeneficiaries(beneficiaries);
String requestID = requestService.submitRequest(requestData);
System.out.println("Request ID :: " + requestID);
}