Migration of a Chosen Architectural Pattern to Service Oriented ...

Chapter 5. Guidelines 136The migration process identified few technology related issues affecting themigration. The issues were following:1. Encapsulation – The project had very poor implementation that even didnot include encapsulation of properties of classes.All the properties were accessiblevia ..Lack of access methods (get /set)did not allow migrate classes as there were. Additional implementation ofaccess methods was enforced by openESB. In fact this is very minor issuebecause today Integrated Development Environments (IDE) allows generatingaccess methods automatically. The IDEs allow also to identify placesin the code where a property is used explicitly. Both features helped torefactor code in required scope.2. Redundant operations – Connection to a service requires creation of a serviceclient in the application. Netbeans supports this activity by generationof stubs of services, ports, connections, operations and messages stubs automatically.IDE will generate only stubs of classes that are inputs foroperations or that are building blocks of operation input message. So farso good, but the problem arises in special circumstances as it was withmigrated project, namely one of the classes extended the other (CrComputerextends CrAsset) and this sub class (CrComputer) was neither a partof any existing operation of Canonical Resource service nor a part of anymessage accepted by this service. So when a user wanted to pass CrComputerobject through an operation which takes CrAsset as an argument(what is possible thanks to polymorphism), it was impossible because astub for CrComputer was not created; consequently a user has no possibilityto use CrComputer stub at all. Creation of CrComputer stub manuallydoes not work either because the IDE recognizes changes and before run, itrebuilds generated classes, besides there is no guaranty that autogeneratedclient does not depend on any “behind the scene” configuration files. Theonly possible solution was to create a “doing nothing” operation that takesCrComputer as an input- this operation ensures that the missing stub isgenerated properly.3. Dependency refresh – IDE generates and refreshes automatically dependenciescreated during project development, at least in theory. It appearedseveral times that a part of removed dependency was left somewhere in aWSDL document, configuration file or somewhere else. Each case causedhard to find problems.4. Schema inclusion – XML schema allows to include other schemas from thesame or different namespace and use imported elements/complex types asown. The problem arises when a schema that imports other schemas isused in a WSDL document, this in turn is an input for automatic client