A big variety of new modern programming technologies exist in today's market and each of it provide different approaches for the same problems. It is quite a challenge for a project manager or a system architect to decide which technology is best for their project and a lot of time should be spent for analysis before some decisions could be made. The main purpose of this work is to create a reusable model for JAVA applications that is based on cutting edge technologies such as Aspect-Oriented Programming, Object databases and Model-View-Controller architecture. This work provides research data that could be used for analysing what influence will these new technologies have for the system. Created model is based on aspect oriented programming. The key component is a TransactionalAspect which does automatic database session and transaction management. It also provides session pooling for better reliability and performance and thread safety by using ThreadLocal for more complex applications. As a result a model was created that helps to manage 4 main stages of system development processes: project analysis precess, architecture process, coding process and system support process. Helps to develop a quality system on time and save project expenses at the same time.

Šiame magistro baigiamajame darbe lyginamos objektinių ir reliacinių duomenų bazių taikymo galimybės objektiškai orientuoto programavimo kontekste. Duomenų bazių ir objektiškai orientuoto programavimo naudojimas iškelia dvi pagrindines problemas. Pirma problema yra reliacinių duomenų bazių ir objektiškai orientuotų programavimo kalbų nesuderinamumas. Antra – duomenų bazių naudojimas judriųjų programų sistemų kūrimo metodikų aplinkoje. Norint palyginti reliacinių ir objektinių duomenų bazių taikymo galimybes buvo nuspręsta sudaryti metodų ir įrankių, skirtų iškeltoms problemoms spręsti, vertinimo modelį. Kadangi iškeltos problemos buvo per stambios vertinimo modelio sudarymui, jos buvo detalizuotos. Vertinami įrankiai ir metodai buvo suskirstyti į keturias kategorijas pagal prigimtį. Iš kiekvienos grupės buvo vertinamas vienas įrankis ar metodas. Darbo pabaigoje visi gauti rezultatai agreguoti ir pateiktos objektinių ir reliacinių duomenų bazių taikymo rekomendacijos, išskirti privalumai ir trūkumai. Beveik pagal visus vertinimo kriterijus objektinės duomenų bazės įvertintos maksimaliais balais. Tačiau iš vertinimo rezultatų paaiškėjo, kad ir jos turi tam tikrų taikymo apribojimų - tokių kaip lėtas duomenų išrinkimas esant dideliam transakcijų skaičiui. Automatinio atvaizdavimo įrankiai prastai tinka projektams, naudojantiems judriąsias programų sistemų kūrimo metodikas, ir sunkiai pritaikomi sudėtingoms hierarchinėms struktūroms atvaizduoti. Reliacinių koncepcijų integravimas... [toliau žr. visą tekstą] / This MA paper aims at object and relational databases application comparison in the context of object oriented programming. Joint usage of databases and object oriented programming raises two problems relevant today. First problem is impedance mismatch of relational databases and object oriented programming languages. Second – database usage in agile software development process environment. In order to define application area of object and relational databases it was decided to compose assessment model to compare solutions available today. Since chosen problems were too bulky they were detailed. The evaluated methods and tools were categorized into four groups by their nature. One tool or method from each group was evaluated. In the end of this MA paper all results were aggregated into object and relational databases usage guidelines and databases usage pros and cons. Object databases got the best evaluations in almost all defined criteria. However, evaluation also showed that object databases have some restrictions in application, such as bad performance when using multiple transactions. Object-relational mappers are not suitable for storing complex hierarchical class structures and usage with agile software development processes. Relational concepts integration into intermediate objects can be used only for very simple object schemes. Linq, evaluated in relational concepts integration with object oriented programming languages category, is still in development, but in... [to full text]

GLOBDATA is a project that aims to design and implement a middleware tool offering the abstraction of a global object database repository. This tool, called COPLA, supports transactional access to geographically distributed persistent objects independent of their location. Additionally, it supports replication of data according to different consistency criteria. For this purpose, COPLA implements a number of consistency protocols offering different tradeoffs between performance and fault-tolerance. This paper presents the analysis of one of two strong consistency protocols for the GLOBDATA system, the voting protocol. A protocol relies heavily on the use of atomic translation primitive as a building block to serialize conflicting transactions. The paper presents an in-depth description of the conceptual model using UML-based analysis of the protocol which later is used to define the PLA (piece-linear aggregates) model of the system, a discrete event-based simulation of the processes. As a result of the work, the PLA model is ready to be used to validate, verify and simulate various behavioral and performance characteristics of the model using mathematical proof techniques.