How to implement Generic function in restricted mode?

             As the earlier post implements the generic function in java. This program restricts the data type as numbers. This uses <T extends Number> for restriction.

Steps:

• ·       Include the built in package “java.util.Scanner”.
• ·       Create a class with main function. A generic function printIT() with number restriction is created.
• ·       The input is given by the user. The first number is integer and the second number is float.
• ·       If it mismatches, it throws the exception. Otherwise,it prints the number.

#Program

import java.util.Scanner;

public class sampleGr {

    public static <T extends Number> void printIt(T value) {

        System.out.println("The value is: " + value);

    }

    public static void main(String[] args) {

              Scanner scanner = new Scanner(System.in);

        System.out.print("enter the first value as integer and next value as float");

        int no = scanner.nextInt();

        float a = scanner.nextFloat();

        printIt(no);

        printIt(a);

    }

}

Output is given below.

C:\raji\blog>javac sampleGr.java

C:\raji\blog>java sampleGr

enter the first value as integer and next value as float

23

5.6

The value is: 23

The value is: 5.6

Exceptions are given as follows….

C:\raji\blog>java sampleGr

enter the first value as integer and next value as float

3.4

Exception in thread "main" java.util.InputMismatchException

        at java.base/java.util.Scanner.throwFor(Scanner.java:964)

        at java.base/java.util.Scanner.next(Scanner.java:1619)

        at java.base/java.util.Scanner.nextInt(Scanner.java:2284)

        at java.base/java.util.Scanner.nextInt(Scanner.java:2238)

        at sampleGr.main(sampleGr.java:10)

 

C:\raji\blog>java sampleGr

enter the first value as integer and next value as float

23

rt

Exception in thread "main" java.util.InputMismatchException

        at java.base/java.util.Scanner.throwFor(Scanner.java:964)

        at java.base/java.util.Scanner.next(Scanner.java:1619)

        at java.base/java.util.Scanner.nextFloat(Scanner.java:2522)

        at sampleGr.main(sampleGr.java:11)

 

C:\raji\blog>java sampleGr

enter the first value as integer and next value as float

rr

Exception in thread "main" java.util.InputMismatchException

        at java.base/java.util.Scanner.throwFor(Scanner.java:964)

        at java.base/java.util.Scanner.next(Scanner.java:1619)

        at java.base/java.util.Scanner.nextInt(Scanner.java:2284)

        at java.base/java.util.Scanner.nextInt(Scanner.java:2238)

        at sampleGr.main(sampleGr.java:10)

Note :” <T extends String>”. If you are using this keyword, this will hold only String values instead of all data types.

Thus the way of implementing Generic function in restricted mode in java in efficient way. You can use these type of restrictions based on the requirements. Keep Coding!!!