Technigally

Java

Java is a high-level programming language. It was developed by Sun Mircrosystems and the first version was released in 1995. Java is a object-oriented programming language.

Advantages of Java:
The Features of java listed below:

  • Object-Oriented
  • Platform Independent
  • Simple
  • Portable
  • Robust
  • Interpreted
  • High Performance
  • Multithreaded
What is method Overloading?
When a java program contains more than one method with the same name but having different signatures/properties, then it is called method Overloading.

What is method Overriding in java?

when a java program contains more than one method that having the same name, same number of arguments/parameters and having same type signature/property is known as method overriding.

Java is not cent percent Object-oriented? Why?

Java is not cent percent Object-oriented because it making the use of 8 primitive datatypes such as boolean, byte, char, int, float, double, long, short which are not objects.

What is IDE?

IDE means Integrated Developement Environment. An integrated develeopment environment is a software that takes the basic tools required to write and test software. An IDE that consists of source code editor and build in automated tools and a debugger.

List few Java IDE's?

Eclipse, NetBeans, Android Studio, BlueJ, JDeveloper etc.

What is meant by Object Cloning?

Object Cloning, it is used to create/maintain a copy of the orginal object. If a class that needs cloning it must implements the java.lang.Clonable interface and override the clone method from the object class.

What is collection in java?

Collection is a group of individual objects. It represents as a single unit. Java collection is a framework. The collection framework that provides an architecture to store and manipulate the group of ojects. Before collection framework was introduced the standard methods for grouping java objects were Arrays or Vectors or Hashtables.

What are the default array values in java?

If we don't assign the values for the array elements, in that time the other elements tries to access them. Then the compiler doesn't produce any error and it assigns values which are not garbage values. The default assigned values are listed below:

  • int : 0
  • boolean : false
  • double : 0.0
  • String : null
  • User Defined Type: null

What is an Exception in java?

Exception is an event, comes during the execution of a program. This disrupts the normal flow of instructions.

What is Hibernate in java?

Hibernate is a Java Framework. This framework simplifies the development of java application to interact with the database. It is an open source, light weight tool. This tool is called as ORM. ORM means Object Relational Mapping. Hibernate implements the specifications of JPA (Java Persistence API) for persistence of data.

What is an Enumeration in java?

Usually, enumeration is called as enum. Enumeration is an interface that contain methods for accessing the original data structure from which the enumeration is obtained and it allows sequential access to all the elements stored in the collection.

What is Web Application?

We can create the application in one environment and execute in the same environment and different environment is called web application. Ex: Facebook, Twitter, Gmail etc.

What are the Oops concepts in java?

Oops concepts includes:

  • Inheritance
  • Encapsulation
  • Polymorphism
  • Abstraction

What is the life cycle of a servlet?

  • The servlet is intialized by calling the init() method
  • The servlet calls service() method to process a client's request
  • The servlet is terminated by calling the destroy() method

What is meant by JDBC Driver?

JDBC Driver is a software component that enables java application to interact with the database. The 4 drivers of JDBC are listed below:

  • JDBC-ODBC bridge driver
  • Native-API driver(partially java driver)
  • Network Protocol driver(fully java driver)
  • Thin driver(fully java driver)

What are the steps that to connect to the database in java?

  • Registering the driver class
  • Creating connection
  • Creating Statement
  • Executing the quries
  • Closing the connection

What is the DriverManager class in JDBC?

The DriverManager class manages the registered drivers. It can be used to register and unregister drivers. It provides factory method that returns the instance of Connection.

What is JDBC Connection interface?

The connection interface maintains a session with the database. It provides factory methods that returns the instance of Statement, PreparedStatement, CallableStatement and DatabaseMetaData.

What is the purpose of JDBC ResultSet interface ?

The ResultSet object represents a row of a table. It can be used to change the cursor pointer and get the information from the database.

What is JDBC ResultSetMetaData interface ?

The ResultSetMetaData interface returns the information of table such as total number of columns, column name, column type etc.

What is batch processing in JDBC ?

Batch processing helps you to group related SQL statements into a batch and execute them instead of executing a single query. By using batch processing technique in JDBC, you can execute multiple queries which makes the performance faster.