Lecture 56: Case Studies—I – Transcript

00:13so this is the last week of this course it is the twelfth week now so far we have learned a lot of regarding the Java programming and it is our now time to exercise so practice matters in any programming language learning you can improve your skill only if you can

00:37indulge yourself into doing some work and then practice and practice so considering these things we have planned few projects that you can take off so that you can deal the projects try to implement and then okay then you can learn many more things which basically is not possible to learn only just using

01:03or attending a course through video course or whatever it is the earth so project is very important so now we will discuss in this week a bunch of projects will be discussed how to solve all these projects and to solve these projects what are the other skill set that you should have all these things will be

01:26discussed one by one so let us have the past projects that we are going to discuss about it is a data entry systems so by the name you can understand that we have to develop our software by which a data can be entered now obviously data entry should be related to certain

01:51application so here we will consider the application regarding the data entry for the students record so this basically for this project you need basic concepts about encapsulation inheritance and then information hiding in the form of access specifier the

02:17concept of package and little bit DUI programming as you can see we have two develop one program it is just a mini software we can say if you can develop this program then at a later stage any large-scale program also can be developed it's similar to the same application now data entry application

02:41is huge it is a very higher actually and this program is a simple one that we have to plan so that you can do it maximum time that you can think for solving this project only one month so in a month in fact for some students it will take only one week in fact anyway so at the maximum you can spend time to

03:06implement only now let us discuss about the idea of the projects here the idea it is you have to declare a class the name of the class you can give as a student this is because we are going to enter the record or information about a student so there should be a class declaration for that now this class

03:32should take into account the different varieties of students students may not be the uniform only there may be different category of students like some students may be studying only undergraduate course some students may be postgraduate course namely M Tech or PhD there may be some higher than the PE course also say post doctorate fellow or

03:56scientists like so we have and obviously as you know so data entry for UD students may not be same the data in T for a PG student like a research scholar this is because there are maybe some methods which is required which does not require in case of other category of objects then we have to decide a

04:22procedure about data entering from the keyboard so it is first we will consider about console based data entry from the Kiawah keyboard how a user can enter the keyboard it will give a prompt that enter the name of the students then from the keyboard you will give the data and then return then again it will prompt for what is our roll number you have to enter this kind so this is

04:47the console postfix 20 easily you are familiar to this kind of entry when you are learning about C programming or something like that anyway so this is a very trivial job and then finally we have to do the same idea using some different way different way because whenever you use the console based aren t the data usually stored in your main memory and so long your program is in

05:13execution the data will be available however if you quit the program or your system is goes off then your data will be lost on the other hand the data that you entered even if it is a console based also you can pump it into secondary storage so that in file the data can be stored so here data entry also very important that how you enter

05:37the data and where this data ultimately goes to so it is basically file and then finally we will consider about a little bit sophisticated data entity is not console based it is basically we can develop a GUI windows program which allow user to enter the data prompt will be in the UI excel and then data once it is entered from the GI it will directly

06:03go to the file anyway so this is the idea about this project now let us have the different steps so it is better that if the project is of large size we have to solve this project in a physic manner I am giving an idea about how in phase by phase this project can be implemented so the past version of the project that

06:27we have planned here that console based data entry and for these things we have to have the class declaration so encapsulation of all the class two of the students based of inheritance also and all the class that you will build based on this class declaration they should be stored in a package because whenever the large

06:54classes are involved the better idea that you should not store all the classes in on directory instead of you could you should maintain all the classes in a safer safer several several directory in a different directory this will basically help to manage the program at a later stage it is basically required for either modification or up

07:20gradation to latter version like so that is the package concept that you should exercise from here so all the class declaration that you will give it is basically in the form of a package I am giving you a quick look of that how a class of the students will look like so first you have to decide a base class the name of the base class that you can give as a student and then student base

07:48class can includes the fields and methods which I have mentioned here as we see here so these are the different different methods and fields not limited to these on you can think something else also that may be more suitable I have given here for your just a hint now so this is the base class and then as you have told you that class may be a different then all students belongs to

08:16this class student actually and then there will be a category is that ug so Yugi has again different fields which is not there or there may be some method which needs to be over it in there or the method you can declare here you can reuse to define this method here so this is a concept of inheritance that you can follow is a single inheritance Java provides only you use the Sun and also some other data that you can include

08:42which is not here so result ug and this result ug itself is another class okay so course may be another class because a course can include some other what is called the subjects also course under this course subject or on subject to subject 3 and for each subject again they are may be marks Ron marks to marks 3 so these basically the composite subjects now it is up to you up to which details level that you want to go so it

09:09is basically an example of nested class that you can do even the class also all those classes can be declared in the package and I can use it by means of import and others so this way the Batchelor class can be declared like master class can be declared PhD and scientist class can be declared and they are the different class because it has certain fields or methods which is not there either here or there so that is why the different class compositions are

09:35to be taken into account okay so so this is about the different class concepts that you should follow and then store them in the package as you have mentioned that student package it is and then our next step that you should after declaring the class and everything you have to create the objects there may be a number of students can be created belongs to a particular category you can

10:03create the array of objects and for each array of objects you can read the field values the member elements from the keyboard so that is what the idea about and then once you read it whether you're reading is successful or not then you can just define a method the print record so that all these things the data entry through the console again you can plan as a separate class and all these

10:29classes can be put into another directory let the name of this directory that is the package as entry so this is the second part of this first phase namely the entering the data and then hearing the next phase of this is storing the data as you have seen that okay data that you have stored it is stored in the objects only and those objects are stored in an array and this

10:54array is basically in primary memory now so you have to store all the objects into a pile that means of the values that is there in the different fields of an object should be passed into file so in this case you can use the iostream handling more basically you can file handling data for class and then use it and the you can do that and then you can save

11:20this class for the data in tea in another packaged application and this will be your main class actually the data in tea in this case is the main class so in the main class you can use all other class that you have declared in the different packages like students and then data in the NT package it is there so this is a version one our next version is basically so long we have

11:46entered the data and then store it in a file our next version is basically date int 2 so we can store ok earlier okay in the next last version you can think about that ok don't store the data into any file now in the next version we can store the data into a file everything is same only the thing is that the input from the May primary memory will go to

12:09the snow pile memory actually and then this is the version 3 the third third phase of the program we can say here you have to define a GUI for data entry now here again the data will be enter from the graphical user interface that means some text field and then some button will be there all those button also needs to be handled properly and then

12:35keyboard handling event should also be implemented and then once the data is enter one by one it will basically go to the file again now I am giving a quick look up how a data entry skill would look like it is very simple one you can use the AWT package for for these to develop it and in this case you have to have a this is basically the frame this