OODJ Documentation

Dani Akemdu (TP01835) Object Oriented Development with Java

Table of ContentsIntroduction...........................................................................................................................................2

UML Diagram.......................................................................................................................................3

Use Case Diagram.............................................................................................................................3

Class Diagram...................................................................................................................................4

Sequence Diagram.............................................................................................................................5

Object Oriented Programming Concept.................................................................................................6

Classes...............................................................................................................................................7

Objects...............................................................................................................................................8

Constructor........................................................................................................................................9

Inheritance.......................................................................................................................................10

Polymorphism.................................................................................................................................11

Encapsulation..................................................................................................................................12

Screenshots..........................................................................................................................................13

LOGIN........................................................................................................................................13

MAIN MENU..............................................................................................................................13

ADMINISTRATOR MENU........................................................................................................14

ADMINISTRATIVE STAFF MENU..........................................................................................14

ACADEMIC STAFF MENU......................................................................................................15

STUDENT MENU......................................................................................................................15

Limitation............................................................................................................................................16

Future Enhancement............................................................................................................................17

Conclusion...........................................................................................................................................18

References...........................................................................................................................................19

1


Introduction

Student Grade Management System is an application to mantain student exam details

for university. The main purposes of thi application is to store and edit the complete personal

record and examination record of each student. There are four users type which has different

access priority. They are administrators, lectures, administrative staff and student. In this

system, administator has the highest access priority which enable him or her to perform al the

functions. The administator is able to add, delete, edit search and update all records. The

second users are lecture, in charge of a module has the right to enter, view, delete, and edit

marks for given module. Then, administrative staff only has limited functions which are view

and search student details. The last users are students who able to view their assigment and

ecamination marks and module details. The project has taken advantages of the object

oriented programming concept. The system has flexible design easily tp understood and

customized to enhance the system.

2


UML Diagram

Use Case Diagram

3


Class Diagram

4


Sequence Diagram

5


Object Oriented Programming Concept

Nowadays many modern language support Object Oriented Programming (OOP). In

OOP all data are encapsulated and control of data members is protected by the class, and

makes programmer able to monitor how the data is accessed and manipulated. Object

Oriented Programming makes software easier to build, maintain, modify and reuse. In OOP

Concept, everything is grouped into sustainable objects and this Concept is also known as the

Class-based programming language. There are some basic concepts make the program

become Object Oriented Programming. They are Classes, Objects, Encapsulation,

Constructor, Inheritance, Polymorphism, and Nested Classes.

There are several advantages of using Object Oriented Concept. First of all is

inheritance, the inheritance technique makes programmer able to eliminate the redundant

code and extend the existing class to use. Second advantage of Object Oriented Programming

concept is easy to divide the work because the project based on the objects. (Johnson.P,

Lancaster.A, 1999). Third advantage is encapsulation, this technique helps programmer to

build different access of priority and secure program by implementing encapsulation. Last

advantages of OOP concept is allowed the program to upgrade easily from small to large

system. An overview of my research about OOP Concept will be explained further.

6


ClassesClasses are constructs that define objects of the same type. A java class uses variable

to define data fields and methods to define behaviors. As an example in the real world, there

are many individual objects all the same kind, like there may be thousand various of car in

existence. Each car has built from the same blueprint. So, in object oriented terms, the car is

an existence of an object known as car. It intentionally focuses on the basics, showing how

even simple classes can cleanly model state and behavior. The class is created by using the

code ‘class’.

Example :

7


Objects

Object-oriented programming involves programming using objects. Object is an

instance of class which performs a set of related activities. In other word, an object is an

instance of a class which represent a group of similar object. When the object is createdm that

object is able to act as an instance of class that objects represent. An object is created by

using code ‘new’.

Example :

Constructor

Java constructor is

a method that has the same name as the class name (Deitel.M.Harvey. Deitel.J.Paul, 2002, pg

394). Within a constructor method, it does not include any return type; it is because

constructor does not return any values. The constructor is used to initialize the instance

variable of an object. Constructor is different from the methods, point over here are few

things about the constructor.

It must have the same name with the class name. Class name is equals to the

constructor name

It is automatically created the default constructor when the programmer does not

define constructor for a class. The default constructor in created by the compiler.

The differences between constructor and methods are:

o Constructor does not have any return type while the methods have the return

type.

o There is no statement implemented in constructor while the methods have.

8


Using the keyword "super" in Constructor is use to call the constructor in parent class.

It must state at the first line in the body of a constructor.

Using the keyword "this" is used to calls another constructor within same class.

Example:

InheritanceInheritance means that defining relationship between a super class and its subclass.

Inheritance creates a new class definition building upon an existing definition (extends the

original class). The code "extends" is used in this technique to extend the existing class from

the new class. As an example; the child class extends the parent class, so everything that

parent can do, the child class also can perform like parent class. This is how the inheritance

creates relationship between classes. In other word, the subclass can use whatever an object

in the super class. This section explains how classes inherit state and behavior from their

super classes, and explains how to derive one class from another using the simple syntax

provided by the Java programming language.

Example:

9


Polymorphism

Polymorphism plays an important role in allowing objects having different internal

structures to share the same external interface. Polymorphism is a technique to request the

same operation be performed by a wide range of different types of things. This technique

allows method to have the same name to act or perform differently within the same class

family. In OOP concept, the Polymorphism is achieved by different techniques, Method

overloading, operator overloading, and method overriding. Polymorphism shown below is

implemented using the method Overloading technique. It has 2 methods that has the same

name which is set and get methods that perform different function. This shows how the

Polymorphism is implemented in the programming to make extensible for the methods.

Example:

10


11


Encapsulation

Encapsulation or also known as information Hiding is a technique in Object Oriented

Programming Language to combined the data and action or methods into single item and hide

the details of implementation (Tutorial Point, 2010). Meaning that, the class is like a

container or capsules which hide the set of methods, attributes and properties. Some

keywords in encapsulation are private and protected. Private access modifier cannot be use

anywhere outside of the class. To get an access to access private field, it has to create a public

field’s getter method to access from other class. Protected access modifier is slightly much

more not strict, it can access from other class as long as it is in the same package.

Example:

12


Screenshots

LOGIN

This is the login system, if users input valid username and password, the system will go

through to the main menu

MAIN MENU

This is the main menu for administrator, the highest access control of this system can perfom

all feature.

13


ADMINISTRATOR MENU

Administrator menu which is provides the user within the authority to create new

administrator, admin staff, lecturer and student into the system.

ADMINISTRATIVE STAFF MENU

This is Administrative Staff Menu, where the system allows the user to search and view

student information includes module details.

14


ACADEMIC STAFF MENU

This menu shows that Academic Staff user which is lecturer able to search, edit and delete

module mark.

STUDENT MENU

These are the student function. Student use is able to view module and module mark.

15


Limitation

There are some limitations which can be found in the system. The first limitation of

the system is when the system is closed all the data will be lost. Since the program is not

using a database to store the input, the program only keeps the data using the Vector where

once the program exit or stop running, the data also lost. Second limitation is this system not

GUI application, which is not really user friendly.

16


Future Enhancement

To make the system become better in the future, the programmer has chosen several

points as enhancement to be developed:

o Connecting system with database to keep and store the user record which can be

permanently store in the database.

o Implementing Graphical User Interface to make an interactive user friendly system.

o Advancing the Object Oriented Concept into the system developing to make the system

more extensible.

17


Conclusion

This assignment main purpose is to develop an application to maintain student exam

details for a university. The system can help people in University environment to find what

they need, to store and keep track the record. This Student Grade Management System will

be very useful for the user because it helps the staff and administrator to manage all records

in the system, helps student to view the module detail and help lecturer to store the module

marks to the system with different level of user access. In implementation users has much

flexibility to run this program because every user has different access control to perform

selected feature in the system. In conclusion object oriented programming concept is high

reusability.

18


References

Deitel.M.Harvey, Deitel.J.Paul, (2002), Object Base Programming. In: n.d Java How

to Program. 4th ed. USA: Prentice Hall. 394-395, 472

Hariyanto,B., Esensi-esensi bahasa pemograman JAVA.3rd ed. Bandung:

Informatika

Java with object oriented programming and world wide web application “PAUL S.WANG” 1998

Johnson.P, Lancaster.A, (1999), the Advantages of Object Oriented Programming [online], Available:http://pj.freefaculty.org/Swarm/Beta/SwarmUserGuide/swarm.user.user1.02-obj-adv.sect1.html, Last accessed [4th May 2012]

Rob M., 2004, Issues of Structured vs. Object Oriented Methodologies of Systems

Analysis and Design, [online], Available from

http://www.iacis.org/iis/2004_iis/PDFfiles/Rob.pdf [Accessed 10th May 2011]

Tutorial Point, (2010), Java – Encapsulation [online], Available:

http://www.tutorialspoint.com/java/java_encapsulation.htm, Last accessed [12th May

2011]

19

http://www.iacis.org/iis/2004_iis/PDFfiles/Rob.pdf

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OODJ Documentation