COLLEGE OF POLYTECHNICS JIHLAVA Department of Technical Studies Applied Computer Science. Foreigners integration support application

Transcription

1 COLLEGE OF POLYTECHNICS JIHLAVA Department of Technical Studies Applied Computer Science Foreigners integration support application bachelor thesis Author: Oleh Bezpalko Thesis supervisor: PaedDr. František Smrčka, Ph.D. Jihlava 2017

2

3 Abstract The major objective of this thesis is to describe and partially develop a system that will allow non-european citizens from such as Ukraine, Russia, Belarus and Kazakhstan. find work and study opportunities in the Czech Republic. Application will also be able to take all dependent processes under control. It is going to have a role of intermediary that simplifies the submission process and make it possible for applicants to make requests in their mother language and control request status. Keywords Java, spring framework, vaadin framework, hibernate, PostgreSQL, visa, study abroad

4 Prohlašuji, že předložená bakalářská práce je původní a zpracoval/a jsem ji samostatně. Prohlašuji, že citace použitých pramenů je úplná, že jsem v práci neporušil/a autorská práva (ve smyslu zákona č. 121/2000 Sb., o právu autorském, o právech souvisejících s právem autorským a o změně některých zákonů, v platném znění, dále též AZ ). Souhlasím s umístěním bakalářské práce v knihovně VŠPJ a s jejím užitím k výuce nebo k vlastní vnitřní potřebě VŠPJ. Byl/a jsem seznámen s tím, že na mou bakalářskou práci se plně vztahuje AZ, zejména 60 (školní dílo). Beru na vědomí, že VŠPJ má právo na uzavření licenční smlouvy o užití mé bakalářské práce a prohlašuji, že s o u h l a s í m s případným užitím mé bakalářské práce (prodej, zapůjčení apod.). Jsem si vědom/a toho, že užít své bakalářské práce či poskytnout licenci k jejímu využití mohu jen se souhlasem VŠPJ, která má právo ode mne požadovat přiměřený příspěvek na úhradu nákladů, vynaložených vysokou školou na vytvoření díla (až do jejich skutečné výše), z výdělku dosaženého v souvislosti s užitím díla či poskytnutí licence. V Jihlavě dne... Podpis

5 Acknowledgment First of all, I want to thank my parents for their support and understanding over the whole study period, without their help this paper would have never been accomplished. I would also like to express my sincere thanks to PaedDr. František Smrčka, Ph.D. for valuable advices and time spent on helping me with this thesis.

6 Table of contents 1 Introduction Analysis Existing solutions Portal of Ministry of Labour and Social Affairs Portal of Ministry of Education, Youth and Sports Requirements Specification Functional requirements Non-functional requirements Used technologies Java Maven Spring Spring Core Spring Data Spring Boot Vaadin framework Hibernate HQL SCSS Used development tools NetBeans IDE Bitbucket Git SourceTree Pg Admin Implementation Platform and environment Application structure Back-end Front-end ER-Model Use-case model User roles Localization Conclusion... 32

7 9 Future improvements References List of Abbreviations List of used images The contents of the enclosed CD Installation guide... 38

8 1 Introduction As for most of the people the period of studying in the university was is one of the greatest periods of my life. Before applying for study in College of Polytechnics Jihlava programming was my hobby and I couldn`t imagine what is covered on the background. University was that place where I got an idea of what it means to be a programmer. With help of wonderful teachers and well-structured study program I received invaluable knowledge and experience that helped me to choose the profession of life. In this thesis I want to cover the problematics of immigration to the Czech Republic that I faced to 4 years ago. The main purpose of the thesis is to design and at least partially implement a system which will help foreigners with the main aspects of relocation to the Czech Republic. Designed system should simplify general processes mentioned below: 1. Maturity diploma recognition 2. Applying for a job 3. University degree recognition 4. Applying for a visa 5. Document collection and verification 6. Submission process status tracking 8

9 2 Analysis Image 1: Czech Republic immigration statistics Analysing statistical data about number of immigrants that received residence permission on the territory of the Czech Republic provided by Czech Statistical Office I can say that the number of migrants is growing every year. Each year number of immigrants increases with approximately people more than in previous year. That fast growth significantly prolongs application processing time for obtaining a visa, work permit or any other kind of residence. On the image above provided by Czech Statistical Office you can see graphical representation of immigration trend for last 24 years. [1] The second stage of analysis was to concentrate on the purpose of immigration. Due to that I have made more detailed research and statistical data analysis from different sources. As a result, two general reasons were defined. In the first place according to the number of applicants were workers, in the second were students. 9

10 Years Image 3: Number of foreigners that received work permit NUMBER OF FOREIGN GRADUATE STUDENTS IN CR ,000 2,000 3,000 4,000 5,000 6,000 7,000 8,000 9,000 Graduates Image 2: Number of foreign graduate students in the Czech Republic

11 As we can see from diagram both diagrams the number of foreign employees and students that graduated increased. What means that we can expect similar dynamics in the next years. Statistical data represented here are not complete thousands of employees and students from different countries wish to work and study in the Czech Republic but don t know how to manage that due to lack of information and complicated submission process. Ass a summary I can say that it is necessary to create the system where most of the processes will be automated. That will make all the process much faster, transparent and understandable for ordinary people. 11

12 3 Existing solutions This chapter contains information about the solutions that already exist on the market. After making a research next systems were found: Portal of Ministry of Labour and Social Affairs First of them was internal portal of Ministry of Labour and Social Affairs of the Czech Republic. This portal contains guidelines, descriptions, laws and documents required to obtain work permit. However, it also allows applying for certain work position directly by sending request to employer. Another option of the portal is ability to find open job positions in each of the regions of the Czech Republic. [2] Image 4: Portal of Ministry of Labour and Social Affairs of the Czech 12

13 Portal of Ministry of Education, Youth and Sports Second application that I found allows to search for educational institutions and their degree programs all over the Czech Republic. Person is able to select university location, study program, type of study, degree program and field of study. Application by it-self is accessible on one of the pages of Ministry of Education, Youth and Sports of the Czech Republic. Search results can be exported into CSV file. Image 5: Certified educational institution and degree program searcher 13

14 4 Requirements Specification This chapter provides information about functional and non-functional requirements to the system. With their detailed description. Functional requirements The " Foreigners Support Application" system will support all key processes required in this area. Allows you to search available working positions, university degree program to apply for all or will help you to recognize your studies and degrees from countries out of the Czech Republic. Application will support multiple languages, new user registration with address verification, RBAC, operation execution permissions control, secured pages which requires authentication to be accessed, session data storage. Non-functional requirements As system will work with sensitive data it must be reliable and secure. User interface should be user friendly, even intuitive. However all the processes that foreigners deal with are changing all the time so the system should be as much flexible and extendable as possible to make possible application of immediate changes to it. 14

15 5 Used technologies In this chapter are specified and described in details all technologies, platforms and frameworks that were used to develop an application. Java Java is a programming language and a computational platform that was first released by Sun Microsystems in As it is an object-oriented language this allows you to create modular programs, the source code of which can be used many times. It is fast, highly secured and reliable and is able to run on most of devices from laptops to data centres, from gaming consoles to supercomputers. However, it is easy to learn. [3] `In the development of the language great attention was paid to simplicity of the language so Java programs in comparison with programs in other languages are easier to write, compile, debug and learn. Image 6: Java program execution process Java program execution processes by steps: 1. Program files (.java) that contains source code written in Java language are compiled into byte code files (.class). 2. Byte code of the program is translated into binary code (.exe). 3. Binary code is executed by OS. 15

16 The Java language does not depend on the platform. One of the main advantages of the Java language is the ability to transfer programs from one system to another. Because Java programs do not depend on the platform, either at the source code level or at the binary level, they can be run on different systems which is especially important for programs intended for the WWW. Such flexibility and platform independency is possible thanks Java Virtual Machine platform. One the images below we can see visualization of JVM workflow. Maven Tool for building project in one row with Gradle and Ant. The main purpose of Maven is the input project source code make a runnable application in the output. How is it different from the compiler? Briefly the build system calls the compiler in its work and the compiler does not even suspect the existence of an assembly system. If it is longer the assembly in addition to compiling includes a whole range of tasks for which the compiler is not suitable. You can see the list of standard maven tasks below: validate - checks the correctness of the meta information about the project compile - compiles sources test - runs class tests from the previous step package - packages the compiled classes into a convenient format (jar or war, for example) integration-test - sends packaged classes to the integration testing environment and runs tests verify - verifies the correctness of the package and the satisfaction of quality requirements install - adds the package to the local repository, from where it will be available for use as a dependency in other projects deploy - sends the package to a remote production server, from where other developers can get it and use it The entire project structure is described in the pom.xml (Project Object Model) file which should be in the project's root folder. The key concept of Maven is an artifact - it is any library stored in the repository. It can even be some kind of dependency or plugin. [4] Maven advantages in comparison with other project building tools: OS Independent 16

17 Dependency management Build from command prompt is possible Declarative description of the project Spring Spring - often imply not just a framework but a whole family of projects most of which are developed and supervised by Pivotal company and the community. The key of them that were used are: Image 7: Spring architecture Spring Core The root of the platform that provides basic tools for creating applications - managing components, implementing dependencies, transactions, basic access to the database. Basically they are low-level components which are implicitly used by all other components Spring Data Spring Data - project that makes it easier to create Spring-driven applications and use new ways of accessing data such as non-relational databases, map-reduce frameworks, cloud services, and well-improved support for relational databases. 17

18 5.3.3 Spring Boot One of the most used projects which avoids the entire horror of the XML configuration and allows you quickly configure dependencies between components. Also with its help you can easily package your project into an executable self-contained artifact. [5] Vaadin framework Vaadin - a freely distributed framework for creating web applications developed by the Finnish company of the same name. It supports all common browsers from desktop PC to mobile devices and tablets. All development is carried out in Java, but the Java-code is executed only on the server, on the client side all work is done by JavaScript. Image 8: Vaadin runtime architecture 18

19 Structurally Vaadin consists of a server API, a client API and a set of user interface components. Also this framework has a theme engine for creating an interface and a data model that allows you to bind server components directly to data. You can use two main development models: server-side and client-side (browser). Server-side development model allows you to create complete applications without development of the client side, it simply uses the AJAX engine from client-side part which forms a user interface in the browser. The server approach allows you to virtually forget that the development is for the web and develop the user interface almost like a traditional Java program with direct access to data and services on the server. Client-side model allows you to develop widgets and applications in the Java language which are then compiled into a JavaScript executable using the Vaadin compiler based on GWT library from Google. But if you need full access over the DOM structure you can use JavaScript directly. [6] Hibernate Hibernate - is an object-relational mapping solution for the Java language which not only takes care of linking Java classes to database tables, Java data types in SQL data types but also provides tools for automatically building queries and retrieving data from the database. Image 9: Hibernate java class mapping to database mapping 19

20 This hibernate features can significantly reduce the time of development which is usually spent on manual writing of SQL and JDBC code. Hibernate generates SQL calls and frees the developer from manually processing the resulting data set and converting objects, keeping the application portable to all SQL databases HQL HQL is an object-oriented query language that makes it possible for Hibernate framework to communicate with relational database in the way of object oriented queries, where each object represents entire database table. One of the difference in comparison with standard SQL is that HQL supports queries in the form INSERT INTO SELECT... what means that query like: Image 10: Hibernate query example is possible when standard SQL syntax for the form INSERT INTO... VALUES... not supported. SCSS SCSS - dialect of the SASS is a language designed to simplify the creation of CSS-code. Saying in simple words it s upgraded CSS that allows you define variables, creating templates, do mathematical operations inside your styles. SCSS styles in the end are compiled by ruby compiler into plain old CSS. An example below demonstrates us an advantage of using SCSS against CSS. Image 11: SCSS and CSS code comparison 20

21 On the left side we see SCSS where variable is used to store colour value what allows us to redefine colour in multiple places by simple change in one line of code. On the other side the equivalent code is written in CSS. 21

22 6 Used development tools In this chapter will be discussed development tools used for system implementation. Reasons why specific tool was selected, NetBeans IDE While working on my project I used Net Beans IDE for multiple reasons. First of all, it s because I already had some experience of working with this IDE and it seemed to me familiar with simple understandable UI. Second reason was that it is free and you can easily download it from the official website. Bitbucket For my project s remote repository storage. I decided to use Bitbucket. It provides software developers, designers, writers and other professionals whose job it is to create content using computers, work together on their tasks, access the shared wiki and task scheduler, and study the products of other users' work. In Bitbucket you can create any number of closed for viewing from the side of repositories for free, but no more than five people can participate in the work on your free closed projects. If you want to increase their number, you will have to buy paid access to the service. Git To take full control over my code I decided to use version control system called Git. It is a distributed VCS, what means that we do not work with one repository on the server, but everyone has a local copy of the repository. Accordingly, operations such as checkout and commit are performed with a local repository. With each other (or with that on the server), repositories are synchronized with specially designed pull (fetch) and push commands. [7] On the image you can see how actually the working process with Git looks like. Initialize git repository - to start using VCS with your project, first of all you have to initialize git repository inside your project root folder by executing command git init in your command prompt. 22

23 Add files with changes to the staging area - after gin repository initialization you can start work with your files. Then all required changes to the files are done and you want to save them, first thing that should be done is adding all files to staging area by command git add. Doing so tells Git that you want to save the actual state of all files which are in the staging area. Commit staged changes - next required step to save your changes is commit. This command works like confirmation, and after its execution staged files will be saved with their actual changes. By it-self commit tells Git to save changes locally but if you are working in team or your project is stored remotely you have to perform next step to get your changes to the remote instance. Pushing changes - push command stands for sending your committed files to the remote repository instance. On the other side if you are working in a team and changes to remote repository were made by someone else you have to execute Git pull command to apply remote changes to your local repository. Image 12: Git workflow 23

24 SourceTree To have better understanding of what is going on in my project and what changes are applied instead of using standard Git command prompt I decided to use Source tree. If you will take a look on the image below you will understand why I did so. On the images you can see how does it looks working with Git from the command prompt and using SourceTree. Image 13: Work with Git using command line Image 14: Work with Git using SourceTree 24

25 As you can see SourceTree is much more sophisticated tool for working with VCSs, here you can easily track project changes, for teams with multiple participants it is possible to keep on track of who and when made changes and which files were changed. [8] Pg Admin To run postgres database on my machine I installed free database management tool Pg Admin. It is freely available DBMS for comfortable user interface, ability of creating tables, insert, update and delete data. Image 15: Pg Admin tool user interface 25

26 7 Implementation This chapter describes architecture of the application, with visual representation model, detailed explanation of communication between layers and the reason of selection Java platform as a base. Platform and environment After making an analysis for my project I decided to implement it in Java language. Not only due to experience that I had working with this language but also due to great range of out of the box solutions that are already built-in. Application structure The whole project is separated into two modules. First one for frontend development which is based on Vaadin framework and the second one for application business logic that using Spring family projects. Nevertheless, backend part is also a combination of components like data access objects (DAOs) represented as repositories, business objects (BOs) that represents real world objects and services for saving and processing BOs. Image that you see below represents modules connectivity and communication. Image 16: Application structure levels 26

27 On the image we can see four basic layers: 1) On the application top level User interface - sends data transfer objects (DTO) from the user pages to services 2) In case of API use JSON objects 3) Service layer - receives DTOs, validates, process them and convert to BOs, after that generated BOs are sent to repository. 4) Repository receives BOs, binding parameters to HQL query and gives Hibernate to process them. Hibernate depending on database, dialect generates native query and sends it to the database. 5) Database receives the queries and processes them. Back-end Back-end part of the application consists of application business logic and PostgreSQL database. On the application side due to use of Hibernate and Spring Data project, was no need to write even a line of SQL. All of the business object classes are automatically mapped to database tables. Database create-read-update-delete (CRUD) functionality is provided by Java Persistence API (JPA), that takes care over generating CRUD request to the end database. My main idea was to crate back-end services in such a way that they can be would be shared for front-end and API part. That means that all data transfer objects that are used to transfer data from GUI will be also used for API module. Doing so eliminates code duplications, makes it easier to understand. Front-end Front-end part consists of Vaadin framework components, custom views. As the base of UI was created TemplateUI which is parent for all application pages. This TemplateUI contains elements that are shared for all pages such as main application menu, language switcher and other. 27

28 ER-Model In case of using hibernate framework for mapping Java objects to tables, ER-model diagram looks identically with application class diagram. Image 17: ER-model diagram 28

29 Use-case model Image 18: Use-case model representation User roles Table 1: User roles Role Actions Administrator Manages users access rights Manager Register new users Update user personal information Verify user profile Translator Translate new work positions into several languages User Orders services Apply to university Apply for work position 29

30 Localization One of the requirements for this project was to make it usable for user from different countries, for that reasons all text labels and messages are translated into four languages at the moment: English Czech Russian Ukrainian Application localized messages are stored in property (.property) files also called bundles, one property file per language. Example of such file you can see on the image below: Image 19: Localization file example All localization messages are stored in key = value format and are loaded by special resource bundle loader class. The input of this class is message key and language of locale property file. 30

31 Image 20: Function for localized messages loading 31

32 8 Conclusion In conclusion I want to say that high quality analysis and design are the prerequisites for the successful development of the information systems. It is at the initial stages that determine the fundamental aspects of system modelling on which the success of the project depends. Unfortunately, due to system complexity the main goal was not completely reached. Mostly all back-end components and services were developed,but the system is not completely functioning, here you can see the list of remaining issues that have to be fixed: 1) Create UIs for pages 2) Connect UIs with back-end services 3) Connect API Controllers to back-end services 32

33 9 Future improvements This chapter is about future development of the system, new features implementation. 1) Modify application localization process 2) Change user access rights configuration 3) Let the administrator to create user groups with specific roles and permissions 4) Add Google translator API support to translator page to improve translation speed 5) Add intermediate validation service layer for frontent and backend 6) Update parser for work positions loading 7) Add new account type for companies 33

34 10 References 1. Cizinci vzdělávající se na českých školách Statistika&My - měsíčník Českého statistického úřadu. Statistika&My - měsíčník Českého statistického úřadu [online]. Copyright 2016 Český statistický úřad, Statistika [cit ]. Dostupné z: 2. Integrovaný portál MPSV [online]. Dostupné z: 3. Trail: Learning the Java Language (The Java Tutorials). Moved [online]. Copyright 1995, 2015 Oracle and [cit ]. Dostupné z: 4. Maven Welcome to Apache Maven. Maven Welcome to Apache Maven [online]. Copyright 2002 [cit ]. Dostupné z: 5. Spring Boot. [online]. Copyright [cit ]. Dostupné z: 6. Vaadin Framework - #1 Java Web UI Framework for Business Applications - vaadin.com. 301 Moved Permanently [online]. Copyright 2017 Vaadin Ltd. All rights reserved. [cit ]. Dostupné z: 7. Git - giteveryday Documentation. Git [online]. Dostupné z: 8. SourceTree - A free Git & Mercurial client for Windows or Mac Atlassian. Atlassian Software Development and Collaboration Tools [online]. Copyright 2017 Atlassian [cit ]. Dostupné z: 34

35 11 List of Abbreviations DOM - Document Object Model VCS - Version Control System DB - Database RBAC - Role-Based Access Control IDE - Integrated Development Environment SQL - Structured Query Language XML - Extensible Markup Language JSON - JavaScript Object Notation AJAX - Asynchronous JavaScript and XML MVC - Model view controller GUI - Graphical user interface UML - Unified Modelling Language ER-diagram - Entity Relationship Diagram HTTP - Hyper Text Transfer Protocol IMAP - Internet Message Access Protocol POP3 - Post Office Protocol SOAP - Simple Object Access Protocol REST - Representational State Transfer API - Application programming interface OOP - Object-oriented programming CMS - Content Management System CSS - Cascading Style Sheets JVM - Java virtual machine JIT - Just-in-time compilation JRE - Java Runtime Environment 35

36 12 List of used images Image 1: Czech Republic immigration statistics Image 2: Number of foreign graduate students in the Czech Republic Image 3: Number of foreigners that received work permit Image 4: Portal of Ministry of Labour and Social Affairs of the Czech Image 5: Certified educational institution and degree program searcher Image 6: Java program execution process Image 7: Spring architecture Image 8: Vaadin runtime architecture Image 9: Hibernate java class mapping to database mapping Image 10: Hibernate query example Image 11: SCSS and CSS code comparison Image 12: Git workflow Image 13: Work with Git using command line Image 14: Work with Git using SourceTree Image 15: Pg Admin tool user interface Image 16: Application structure levels Image 17: ER-model diagram Image 18: Use-case model representation Image 19: Localization file example Image 20: Function for localized messages loading

37 13 The contents of the enclosed CD 37

38 14 Installation guide Download and install Java version Set JAVA_HOME system variable to C:\Program Files\Java\jdk1.8.0_144 Add C:\Program Files\Java\jdk1.8.0_144\bin to PATH system variable to check if you set your system variables properly open command prompt and type java -version and press ender as an output you should see java version 1.8.0_144 Download and unzip maven to location suitable for you Set M2_HOME system variable to the root of unzipped maven like this D:\Programs\apache-maven Set M2 system variable to %M2_HOME%\bin Add %M2% to the PATH system variable to check if you set your system variables properly open command prompt and type mvn -v and press enter as an output you should see maven version and java version Download NetBeans Ide from its official web page and install it Download and install pg Admin from its official web page In Pg admin create new role mg_admin with password admin Then create database with name mg_data and set mg_admin as the owner After all this steps will be done NetBeans and import project go to Application class and run the application 38