Steps to follow:
1. Write Relation.java as shown in Code-11.5.a below. Please note that the Relation is an interface. (You are welcome to do this work using either command line tools or NetBeans. The instruction here is given using command line tools. In general, using NetBeans is highly recommended.)
* cd \myjavaprograms
* mkdir interfaceexercise
* jedit interfaceexercise\Relation.java
2. Write Main.java as shown in Code-11.5.b below.
* cd \myjavaprograms (if you are not in this directory already)
* jedit interfaceexercise\Main.java
3. Compile Relation.java and Main.java. (You will experience a compile error as described in the subsequent step.)
* cd \myjavaprograms (if you are not in this directory already)
* javac interfaceexercise\Relation.java interfaceexercise\Main.java
4. Note that you will experience a compile error as shown below. This is because you cannot create an object instance from an Interface.
* C:\myjavaprograms>javac interfaceexercise\Relation.java interfaceexercise\Main.java
interfaceexercise\Main.java:5: interfaceexercise.Relation is abstract; cannot be instantiated
Relation x = new Relation();
^
1 error
5. Write Line.java as shown in Code-11.5.c below. It contains a concrete implementation class that implements Relation interface. Note that the all the methods defined in the Relation interface is now implemented.
* cd \myjavaprograms (if you are not in this directory already)
* jedit interfaceexercise\Line.java
6. Rewrite Main.java as shown in Code-11.5.d below.
* cd \myjavaprograms (if you are not in this directory already)
* jedit interfaceexercise\Main.java
7. Compile and run the code using a directory structure.
* cd \myjavaprograms (if you are not in this directory already)
* javac interfaceexercise\*.java
* java -classpath . interfaceexercise.Main
8. Verify the result as following:
* C:\myjavaprograms>java -classpath . interfaceexercise.Main
line1 is greater than line2: false
line1 is equal with line2: true
line1 is equal with line3: false
Length of line1 is 1.4142135623730951
Length of line2 is 1.4142135623730951
Popular Posts
-
Now I will show you how to retrieve the data posted from a HTML file in a JSP page. Consider an html page that prompts the user to enter his...
-
Accessing the Standard CGI Variables: To build the successful web application, you often need to know a lot about the environment in which ...
-
INTRODUCTION TO 'C': C is a programming language developed at AT & T's Bell laboratories of USA in 1972.it was designed by d... -
SQL aliases can be used with database tables and with database table columns, depending on task you are performing. SQL column aliases are u...
-
Learning about Events (Continue) Lets program the Form_Load event. "MsgBox" is Visual Basic command that launch a message box. for... -
Steps to follow: 1. Write Person.java as shown below in Code-11.3.a under polypackage directory. (You are welcome to do this work using eit...
-
The Command Button's KeyPress, KeyDown and KeyUp Events The events that will be mentioned in the following pages are commonly used, and ... -
The SQL AVG aggregate function selects the average value for certain table column. Have a look at the SQL AVG syntax: SELECT AVG(Column1) FR...
-
package interfaceexercise; // Define an interface with three abstract methods. // Any class that implements this interface has to // impleme...
-
We will use the Customers table to illustrate the SQL LIKE clause usage: FirstName LastName Email DOB Phone John Smith John.Smith@yaho...
No comments:
Post a Comment