UML

Visibility

• - private
• + public
• # protected
• ~ default 

Inheritance in java

In Java there are 5 types of inheritance as follows
1). Single Inheritance
2). Multilevel Inheritance
3). Multiple Inheritance[achieved using Interface]
4). Hierarchical Inheritance
5). Hybrid Inheritance

 Before starting i would like explain few terms which we will using below. They are as follows
*Super Class is nothing but a Parent class or Base Class
*Sub Class is nothing but a Child Class which is inherited form the Parent Class

 1). Single Inheritance
In this type of Inheritance there will be only one super class and only one sub class will be involved
let us assume A is super class and B is sub class of A

A

↓

B

Here Class B is inherited from Class A. This type of inheritance is named as Single Inheritance.

2). Multilevel Inheritance
In this type of Inheritance the super class is inherited by its sub class and this sub class will be inherited by the another sub class. let us assume A is super class and B is sub class of A and C is sub class B

A

↓

B
↓

C

Here Class C is inherited form Class B and this Class B is inherited form its parent class A. This type of inheritance is named as Multilevel Inheritance.

3). Multiple Inheritance

In this type of Inheritance the super class is inherited by its sub class and this sub class will be inherited by the another sub class. let us assume A is super class and B is also a super class and C is sub class of A & B

A  B

↓  ↓

C

Note: Multiple Inheritance is not supported by Java, where the possible way to achieve this can be done using Interface 

4). Hierarchical Inheritance

In this type of Inheritance there will be only one super class which is inherited by many sub class. let us assume A is super class and B and C are sub class of A.

A

↓  ↓

B  C

5). Hybrid Inheritance
 All the above type of Inheritance combination is mixed together to build a Hybrid Inheritance. It could be

A

↓  ↓
B  D E F

↓ 

G

These are the different types of Inheritance in java

Access Specifier in java

This table tells you which other classes can see your classes data members and member methods when you use access specifiers

	private	default	protected	public
Same Class	✔	✔	✔	✔
Same Package Subclass	✖	✔	✔	✔
Same Package Non-Subclass	✖	✔	✔	✔
Different Package Subclass	✖	✖	✔ Note: Using Child refernce	✔
Different Package Non-Subclass	✖	✖	✖	✔

Android for Beginners

For Android Application Development you need the following environment setup on your system,
let me make you bit clear before starting and steps you need to follow and software required as well

• Environment [ IDE - Integrated Development Environment ] for code development
• this Environment could be Eclipse, NetBeans, etc., all these ide's are open source
• but i will be speaking about Eclipse as i am aware of that only 
• you could download the latest version from here

• Android Plugin to link with the Environment 
• here the Environment which we will choosing is Eclipse as i said earlier, so we need to link our IDE with the Android Eclipse Plugin
• you could download the plugin form here

• Development Kit that links the with above and interact for Android App development.

Note: the java jdk version should be higher than 1.5 or else this java cause you some issue