Why do we require Advanced Java?

Advanced Java: 1

We are going to learn advanced java in question answer form.

Q1. What is CORE JAVA?

• Core java is used to developed standalone applications.
• Core java means only language learning.
• Core java is required to learn language but not sufficient.
• Core java 25years outdated because now a days no one use standalone application for businesses.

Q2. What is Advanced Java?

• To make the project online that is web application learn advanced java.
• if you want to develop internet-based application learn advanced java.
• if you want to become java professional you must learn advanced java.
• Collection of various tools and technologies through which we can develop dynamic application.
• To communicate with the database located at remote location we need Advanced Java.
• We can develop network centric, web based, enterprise applications using advanced java.

Q3. What is the basis for company to provide services to customer?

• For Ex. Bank --- Provides --- services to customers. Now using what they provide services to customer, so the answer is DATA. Online banking, online shopping any application to provide the services data is more important. (Joke in IT industry: More than wife data is important)

Q4. Which feature should data possess?

• Now question comes to your mind why data requires features? data must require features because if data is not having any feature, then there is no use of such data.
• Data of web application must possess following features:

1. Persistence (Permanence): for ex. bank having data customers account no if after few days bank forgot customer account number, can we think that application or project or software work?
2. Security: your data must be secure.
3. Easy accessibility: This feature is also required for easy access of data.

For example, consider a scenario if i stored data in hard disk, data is permanent, but it is not secure and not easily accessible. so can you think you will get all those things in one place. Yes, if we store data in a database data will possess all features permanence, secure, easy accessibility, instead of writing 500 lines of code to access data from file system we easily get data from database through SQL statements.

Q5. Now if database is there then why java is required?

• To answer this question let's assume, SBI bank all customers details stored in database. SBI is having 1000 branches all over India. suppose customer from Pune wants to know the balance enquiry so to know the balance can customer open SQL prompt and write SQL Statement for the same or can bank person open the SQL prompt and write SQL statement for the same as SELECT balance FROM Account WHERE Accountno=123.
• What do you think can bank person knows the SQL Statement definitely not. secondly how SQL appears in Pune branch because database server is located somewhere in Mumbai branch.
• From this we come's to know that database is weak in data processing and only database is not sufficient.

Q6. What is the Role of Java in Web application?

• Role of java is Backend processing.
• Communicating with the database and perform CRUD operations.
• For example, consider the use case of balance enquiry.
• When user enters his or her Account no: 1234 and click on getBalance button, java program will send select statement to database. similarly for CRUD operation java program will send insert, update and delete statement to the database.
• Data processing is done by java. 
• Making processed data to the frontend.
• java role is backend processing. (How to communicate with database is the first part of advanced java JDBC and Servlet)

Q7. What is the Obstacle for java -database communication?

• Java Program     --------------------------------------      Database
• As we know in core java when we want to do any operation using java it will do it with java method calls. now using java program, we want to retrieve balance from the database for that purpose from java side it will call method for the same. 
• now who will receive that method call answer is database will receive that method call but database does not understand method call. database understand only SQL Statement.
• Now we have to make request in the form of SQL Statement using java, but java compiler does not accept SQL directly.
• So, what we can say that java and database are heterogeneous to each other. 
• This is the main obstacle for java database communication.

but still java wants to communicate with database, so we can simulate this problem with real world entities like PM of India wants to communicate with PM of Russia. both doesn't understand language of each other. So, to overcome this obstacle they use mediator or translator for the same so that they can understand each other's opinion.

Similarly, we use JDBC as a mediator or translator between 

Java (method calls) --------------------    JDBC     -------------------------   DBMS (SQL Statement only)

Q8. How java database communication?

• By using JDBC java database connection is possible.

Next session will discuss.:

1. What is JDBC?

2. What is architecture of JDBC?

3. What is a JDBC client?

4. What is the JDBC Programming Model?

5. What are the JDBC Client side requirements to communicate with the database?

6. What is JDBC API?

7. What is a JDBC Driver?