Pratik kamble at 12:39, 3 May 2019

2019-05-03T12:39:35Z

PoojaMoolya at 12:45, 24 April 2019

2019-04-24T12:45:04Z

Sandhya.np14 at 11:17, 18 May 2017

2017-05-18T11:17:36Z

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Sandhya.np14 at 10:32, 18 May 2017

2017-05-18T10:32:06Z

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Pratik kamble at 13:57, 20 February 2017

2017-02-20T13:57:07Z

PoojaMoolya at 10:52, 13 January 2017

2017-01-13T10:52:29Z

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PoojaMoolya: Created page with " {| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Welcome to the''' Spoken Tutorial''' on''' Java Interfaces.''' |- | 00:05 | In thi..."

2016-08-12T08:43:49Z

Created page with " {| border=1 | <center>'''Time'''</center> | <center>'''Narration'''</center> |- | 00:01 | Welcome to the''' Spoken Tutorial''' on''' Java Interfaces.''' |- | 00:05 | In thi..."

New page

{| border=1
| <center>'''Time'''</center>
| <center>'''Narration'''</center>

|-
| 00:01
| Welcome to the''' Spoken Tutorial''' on''' Java Interfaces.'''

|-
| 00:05
| In this tutorial we will learn about:
* Creating an''' interface'''
* Creating an''' Implementation class''' and
* Usage of''' Interfaces'''

|-
| 00:16
| For this tutorial, I am using

* '''Ubuntu 12.04'''
* '''JDK 1.7 '''and
* '''Eclipse 4.3.1'''

|-
| 00:28
| To follow this tutorial, you should have knowledge of basics of''' Java''' and''' Eclipse IDE.'''

|-
| 00:36
| You should also have the knowledge of''' subclassing''' and''' Abstract classes '''in''' Java.'''

|-
| 00:42
| If not, for relevant''' Java''' tutorials, please visit the link shown.

|-
| 00:48
| First let's understand what is an '''interface'''.

|-
| 00:52
| An''' Interface''' contains a set of''' abstract methods''' and''' static data members'''.

|-
| 00:58
| It defines the signatures of a set of''' methods,''' without the body.

|-
| 01:04
| It is declared using the '''interface''' keyword.

|-
|01:08
| A''' class''' can implement an''' interface''' using the''' implements''' keyword.

|-
| 01:13
| A''' class''' can implement more than one '''interface.'''

|-
| 01:17
| All the''' abstract methods''' defined in the''' interface''' or''' interfaces''' must be implemented in such '''classes'''.

|-
| 01:25
| Now let us explore the differences between an''' interface''' and an''' abstract''' class.

|-
| 01:32
| All the methods in an''' interface''' should be''' abstract.'''

|-
| 01:36
| Within''' interface''' there should not be any

* '''constructors'''
* '''concrete methods'''
* '''static methods '''and
* '''main method'''

|-
| 01:46
| But an''' abstract class''' can have all these inside it.

|-
| 01:50
| The variables in an''' interface''' should be''' static''' and''' final.'''

|-
| 01:55
| There are no such restrictions for an''' abstract class'''.

|-
| 02:01
| Next we will see an example for an '''interface'''.

|-
| 02:06
| Here the '''interface''' name is''' Animal.''' It contains three '''abstract methods talk(), see()''' and''' move().'''

|-
| 02:15
| All such '''methods''' in an '''interface''' are implicitly''' public''' and''' abstract'''.

|-
| 02:21
| An''' interface''' can also contain constant variable declarations.

|-
| 02:27
| Here, the constant string value''' “Mammal”''' is assigned to the variable''' “type1”'''.

|-
| 02:34
| And''' “Reptiles”''' is assigned to the variable''' “type2”'''.

|-
| 02:39
| All''' constant values''' defined in an''' interface''' are implicitly''' public, static''' and''' final.'''

|-
| 02:47
| Next, we will see how to create an '''implementation class''' for an''' interface''' with an example.

|-
| 02:55
| Here''' Human''' is a''' class''' which implements the''' Animal interface.'''

|-
| 03:00
| So it must provide implementations for the '''methods talk(), see()''' and''' move().'''

|-
| 03:07
| A '''class''' can also implement''' multiple interfaces'''.

|-
| 03:12
| As shown in the example, the''' class Human '''implements two''' interfaces Animal''' and''' Action.'''

|-
| 03:19
| Note that a''' comma operator''' used in the syntax is to identify the different''' interfaces.'''

|-
| 03:27
| Now this''' class''' should provide implementations to all the''' abstract methods''' in both''' Animal''' and''' Action interfaces.'''

|-
| 03:36
| The figure here represents an '''implements''' relation.

|-
| 03:41
| The''' Animal class''' is an''' interface.'''

|-
| 03:44
| The''' Human '''and''' Snake classes''' are the two '''implementation classes'''.

|-
| 03:50
| The '''Human class''' provides its own different implementations for''' talk(), see()''' and''' move() methods.'''

|-
| 03:59
| And the '''Snake class''' provides its own different implementations for''' talk(), see()''' and''' move() methods.'''

|-
| 04:08
| Let us understand the usage of '''interfaces '''with a sample program.

|-
| 04:13
| Now we will switch to''' Eclipse''' and create a new project called''' InterfaceDemo'''.

|-
| 04:21
| Here we will create the necessary''' classes''' and''' interface''' to demonstrate the usage of''' interfaces.'''

|-
| 04:28
| Now, right click on''' src''' folder and click''' new-> interface'''.

|-
| 04:35
| Type the name as''' Animal''' and press '''Enter'''.

|-
| 04:39
| Note that the '''“interface”''' keyword is used for defining an '''interface'''.

|-
| 04:45
| Now type the code as displayed on the screen.

|-
| 04:48
| Next let us create the''' implementation classes.'''

|-
| 04:53
| Right click on the '''default package '''and create a''' class''' called''' Human.'''

|-
| 04:59
| Now to make this an implementation class of''' Animal, '''type''' implements Animal.'''

|-
| 05:06
| Now we can see, an error comes up in the''' Eclipse IDE.'''

|-
| 05:11
| This error indicates that, we should provide an implementations to the '''Animal interface.'''

|-
| 05:17
| Let us see how to rectify this error.

|-
| 05:21
| Now let us define the''' methods talk(), see()''' and''' move().'''

|-
| 05:26
| So type''' public void talk( )''' Within curly brackets type '''System.out.println''' within quotes''' I am a human and I belong to'''

|-
| 05:39
| Now we can use the value of the''' static, final variable type1''' declared in the''' Animal interface'''

|-
| 05:47
| So type '''+ Animal.type1+''' within quotes''' family semicolon'''.

|-
| 05:56
| Let us now implement the '''see() method'''. So type''' public void see( )''' Within curly brackets type '''System.out.println''' within quotes''' I can see all colors semicolon'''

|-
| 06:13
| We should also define the''' move() method'''

|-
| 06:17
| So type''' public void move( )''' Within curly brackets type '''System.out.println''' within quotes''' I move by walking semicolon'''

|-
| 06:31
| Note that the error disappears, once all the '''methods''' are implemented.

|-
| 06:36
| Next we will see how to define the''' Snake class.'''

|-
| 06:40
| I have already created it in my project. Please create the '''snake class''' in your project and type the following code as displayed on the screen.

|-
| 06:51
| Now let us go through the code.

|-
| 06:55
| We can see that all the '''methods''' of the''' Animal interface talk(), see()''' and''' move()''' are implemented inside this '''class'''.

|-
| 07:04
| Here the''' talk() method''' prints “'''I am a snake and I belong to'''. Then the value of''' Animal.type2''' is to be printed and then''' “family”'''

|-
| 07:16
| Here the''' see() method''' prints “'''I can see only in black and white”'''

|-
| 07:21
| The''' move() method''' prints''' "I move by crawling"'''

|-
| 07:26
| Note that the''' Human class''' has its own implementations of''' talk(), see()''' and''' move() methods'''.

|-
| 07:33
| And the''' Snake class''' has its own implementations of''' talk(), see()''' and''' move() methods'''.

|-
| 07:41
| Now right click on the '''default package''' click''' new-> class''' and then type name as''' Demo.'''

|-
| 07:49
| Inside this '''class''', we will have the''' main method''', So type''' main''' and then press ctrl+space to generate the''' main method.'''

|-
| 08:00
| Type the following code as displayed on the screen. In this line, we instantiate the''' Human class''' using the''' Animal interface.'''

|-
| 08:09
| This is represented as '''Animal h equals new Human();'''

|-
| 08:16
| Now we can invoke the different '''methods''' using this object as

'''h.talk()'''

'''h.see();'''

'''h.move();'''

|-
| 08:28
| Next, we instantiate the''' Snake class''' using the''' Animal interface.'''

|-
| 08:33
| This is represented as '''Animal s equals new Snake()'''

|-
| 08:39
| Now we can invoke the different '''methods''' using this object as

'''s.talk();'''

'''s.see();'''

'''s.move();'''

|-
| 08:50
| Now let us run this''' Demo''' program. So right click on the'' '''''class Demo''' and then select''' Run as -> Java Application.'''

|-
| 09:01
| We can see the output as '''I am a human and I belong to Mammal family'''

|-
| 09:07
| '''I can see all colors''' and '''I move by walking'''

|-
| 09:11
| These are printed by the''' talk(), see()''' and''' move() methods''' invoked using the''' Human class object h.'''

|-
| 09:19
| We can also see in the output '''I am a snake and I belong to Reptiles family'''. '''I can see only in black and white''' and '''I move by crawling'''

|-
| 09:30
| These are printed by the''' talk(), see()''' and''' move() methods''' invoked using the''' Snake class object s.'''

|-
| 09:39
| This brings us to the end of this tutorial. Let us summarize.

|-
| 09:44
| In this tutorial we have learnt about

* Creating an''' Interface'''
* Creating an''' implementation class '''and
* Usage of''' interfaces'''

|-
| 09:54
| As an''' assignment''' Create an '''interface Vehicle''' which contains the methods''' brake()''' and''' run().'''

|-
| 10:02
| Create another '''interface Fuel''' which contains the following methods.

'''fill(String type, int quantity)'''

'''pay(int quantity, int price)'''

|-
| 10:14
| Create a subclass''' Car''' which implements both the '''interfaces Vehicle''' and''' Fuel.'''

|-
| 10:21
| Here''' brake method''' should print''' ”Car, Applies Power brake”''' and the '''run method''' should print''' ”Car is running on 4 wheels”.'''

|-
| 10:30
| Similarly''' fill() method''' can print the type and quantity of the fuel filled.

|-
| 10:36
| For example: 10 Litres of Petrol. '''pay() method''' can be used to print the price to be paid.
For example: Pay Rs.640

|-
| 10:48
| Create another subclass''' Bike''' which again implements both the '''interfaces'''- '''Vehicle''' and''' Fuel.'''

|-
| 10:56
| Here '''brake method''' can print ”'''Bike, Applies hand brake”''' and the '''run method''' can print “'''Bike is running on 2 wheels”'''.

|-
| 11:05
| Next, implement the '''fill()''' and '''pay() methods''' as explained earlier.

|-
| 11:11
| Finally, create a '''Demo class''' containing the '''main method''' to verify the results.

|-
| 11:16
| The video at the following link summarizes the''' '''Spoken Tutorial Project. Please download and watch it.

|-
| 11:25
| The Spoken Tutorial Project Team

*Conducts workshops using spoken tutorials and
*Gives certificates on passing the online tests

|-
| 11:34
| For more details, please write to us.

|-
| 11:37
| Spoken Tutorial Project is funded by NMEICT, MHRD, Government of India.

More information on this Mission is available at the link shown.

|-
| 11:48
| This script has been contributed by:

Department of Information Technology, Amal Jyothi College of Engineering.

This is Priya from IIT Bombay signing off. Thank you for joining.

|}

@@ Line 9: / Line 9: @@
 |-
 | 00:05
-|  In this tutorial, we will learn about: * Creating an''' interface'''
+|  In this tutorial, we will learn about: Creating an''' interface'''
 |-
 |  00:10
-| * Creating ''' Implementation classes''' and * Usage of  Interface'''.
+|Creating ''' Implementation classes''' and  Usage of  Interface'''.
 |-
 | 00:16
-|  For this tutorial, I am using:
+|For this tutorial, I am using:
 '''Ubuntu 12.04'''

@@ Line 415: / Line 415: @@
 |-
 | 10:29
-|  The Spoken Tutorial Project Team:
+|  The Spoken Tutorial Project Team: Conducts workshops using spoken tutorials and
-* Conducts workshops using spoken tutorials and
-* Gives certificates on passing the online tests.
+Gives certificates on passing the online tests.
 |-
 |  10:38
-|  For more details, please write to us.
+| For more details, please write to us.
 |-
 |  10:41
-|  '''Spoken Tutorial Project''' is funded by NMEICT, MHRD, Government of India.
+| '''Spoken Tutorial Project''' is funded by NMEICT, MHRD, Government of India.
 |-

@@ Line 18: / Line 18: @@
 | 00:16
 |  For this tutorial, I am using
 '''Ubuntu 12.04'''
-* '''Ubuntu 12.04'''
+'''JDK 1.7 '''and
-* '''JDK 1.7 '''and
+'''Eclipse 4.3.1'''
-* '''Eclipse 4.3.1'''
 |-
@@ Line 390: / Line 389: @@
 |-
 | 09:53
-|  Create another subclass''' Bike''' which again implements both the '''interfaces Vehicle''' and''' Fuel'''
+|Create another subclass''' Bike''' which again implements both the '''interfaces Vehicle''' and''' Fuel'''
 |-
@@ Line 430: / Line 429: @@
 |-
 |  10:52
-|  This script has been contributed by: '''Deptartment of Information''' '''Technology, Amal Jyothi College of Engineering'''
+|This script has been contributed by: '''Deptartment of Information''' '''Technology, Amal Jyothi College of Engineering'''
 |-

Java/C3/Java-Interfaces/English-timed - Revision history

Pratik kamble at 12:39, 3 May 2019

PoojaMoolya at 12:45, 24 April 2019

Sandhya.np14 at 11:17, 18 May 2017

Sandhya.np14 at 10:32, 18 May 2017

Pratik kamble at 13:57, 20 February 2017

PoojaMoolya at 10:52, 13 January 2017

PoojaMoolya: Created page with " {| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Welcome to the''' Spoken Tutorial''' on''' Java Interfaces.''' |- | 00:05 | In thi..."