When we were using Java EE for developing web pages then for creating any object of any class we were using new keyword but let suppose our application has to many classes then managing all objects and classes was not easy, then spring comes up with a principle/pattern by which the control of objects(creation, destruction …etc), is transferred to a framework. Which means that the act of connecting objects with other objects, or “injecting” objects into other objects, is done by a framework rather than by the objects themselves. It is called inversion of control.

IOC container in Spring Framework:

We know in IOC control…

why coding guidelines :

We know Java is one of the most popular and widely used programming language. As a developer when we write code then we should flow some coding standard, because when software goes to maintenance then it possible that code will reviewed by some other developer. So as a developer we should make sure that whatever code we are writing should be readable and extendable.

Few of guidelines are :

Naming conventions for classes and interfaces:

All the classes and interfaces should be noun. First letter of class name and interfaces name should be capital and If it contains multiple word than every inner word should start with uppercase. …

when we open any website in our mobile or computer then as a client if we make any request to website then that request will go to server. If our request is for static web page then server will return that static page directly but what happen if we make request for dynamic web page ?

If client make a request which needs to formed dynamically then server send that request to web container like tomcat. In web container there will many servlet for making dynamic web page and In server there is deployment descriptor file(web.xml) …

Database normalization is the process of organizing the attributes of the database to reduce the redundancy in database.

Now we will see why normalization is important in a database -

Let’s suppose we are creating database for our university where detail of each student is stored. In a table we are storing personal information of a student as well as his course detail.

Insertion anomaly :

Now let’s suppose we have to add few new student in our database and all student belongs to same course, then during insertion of these new student we have to add same course information many times which unnecessarily increase the size of our database. …

An exception is an unwanted or unexpected event which occurs during execution of a program and breaks the normal flow of program. It normally happens due to some edge cases mistake by programmer , java provides various way by which we can handle that exception and will make sure that rest of the program after that exception will successfully executed , if we not handle that exception then rest of the code of that program will not executed.

Exception Hierarchy :

All exception and errors are sub class of class Throwable which is base class of hierarchy.

How JVM handle exception :

In java if any exception occur…

Object Oriented Programming :

OOP stands for Object-Oriented Programming. In procedural programming we create procedures or methods that perform operation on data , it becomes highly complex when we use procedural programming on large application , there was lot of security issue then after object oriented programming came where we deal with everything in the form of class and object.

Object and Classes :

Classes and object are two main aspects of object oriented programming. For understanding about object and classes we can think object as a real world entity and class as a template for object. for example let…


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