I've found how to read WSDLs of exposed services:

List<Service> services = ServicePublisher.getServices();
                              for (Service service : services) {
                                        List<ServicePublisher> servicePublishers = ServicePublisher
                                                            .getServicePublishers(service);
                                        for (ServicePublisher servicePublisher : servicePublishers) {
                                                  final Publisher publisher = servicePublisher.getPublisher();
                                                  if (publisher instanceof ContractReferencePublisher) {
                                                            final ContractReferencePublisher contractReferencePublisher = (ContractReferencePublisher) publisher;
                                                            final URI serviceContractURI = contractReferencePublisher
                                                                                .getServiceContractURI();
                                                            System.out.println(serviceContractURI);
                                                  }
                                        }
                              }

It is based on code found in /deploy/contract.war/index.jsp.

Does anyone know where publishers data is stored in database?

Does information about ServicePublishers and wsdl files exposed with JBoss ESB is stored in memory? There's no information about exposed wsdl/contracts in juddi database.