Java Training

Trainning

1.JAVA 历史、应用与前景（为什么要学JAVA）

JAVA History

JAVA VS Javascript


OO Sytax in JAVA

In Java, all non-static methods are by default "virtual functions." Only methods marked with the keyword final, which cannot be overridden, along with private methods, which are not inherited, are non-virtual.

https://www.tecmint.com/wp-content/uploads/2015/07/Java-Platform-Independent-600x450.jpg

2.OOD

Design Pattern Examples
Awesome design patter

Inheritance (IS-A) vs. Composition (HAS-A) Relationship

• a. IS-A Relationship:

  In object-oriented programming, the concept of IS-A is a totally based on Inheritance, which can be of two types Class Inheritance or Interface Inheritance. It is just like saying "A is a B type of thing". For example, Apple is a Fruit, Car is a Vehicle etc. Inheritance is uni-directional. For example, House is a Building. But Building is not a House.

• b. HAS-A Relationship:

  Composition(HAS-A) simply mean the use of instance variables that are references to other objects. For example Maruti has Engine, or House has Bathroom.

• c.Special case

  • Composition :

  Without existence of container object, if there is no chance of existence of contained objects then container and contained objects are said to be strongly associated and this strong association is known as composition.

  Eg: A “university” has several “departments”. Without existence of “university” there is no chance for the “departments” to exist. Hence “university” and “departments” are strongly associated and this strong association is known as composition.

  • Aggregation:

  Without existence of container object, if there is a chance of existence of contained objects then container and contained objects are said to be loosely associated and this strong association is known as aggregation.

  Eg: A “department” has several “professors”. Without existence of “departments” there is good chance for the “professors” to exist. Hence “professors” and “department” are loosely associated and this loose association is known as Aggregation.

3.Build Tool

Gradle 的作用与应用

4.Framework

Spring-Boot, Spring MVC

5.IOC

6.RESR API

7.DB: ORM and Migration