JAVA

Area of triangle java: In the previous article we have discussed Java Program to Find Volume of Prism

In this article we will discuss how to find the area of a triangle in different ways.

Program to Find Area of Triangle

Before jumping into the program directly, first let’s see how to find the area of a triangle.

Area formula of triangle: (width*height)/2

Example:

Example-1

When the width of the triangle = 20.0 
and the height of the triangle = 110.5
Then area of the triangle  => (width*height)/2 
                                          => (20.0*110.0)/2 
                                          = 1105.0

Example-2

When the width of the triangle = 3
and the height of the triangle = 4
Then area of the triangle => (width*height)/2 
                                         => (3*4)/2
                                         = 6

Let’s see different ways to find find area of triangle:

• Using static value
• Using User defined value
• Using Constructor
• Using User defined method

The best and excellent way to learn a java programming language is by practicing Simple Java Program Examples as it includes basic to advanced levels of concepts.

Method-1 : Java Program to Find Area of Triangle Using Static Value

In this the values of width and height are static values, means the values are already defined in the program. So, let’s see the program to understand it more clearly.

import java.util.*;

class Main
{
   public static void main(String args[])
   {   // width of triangle
      double width = 20.0;
      // hight of triangle
      double height = 100.5;
      //finding area
      double area = (width * height)/2;
      // printing the area
      System.out.println("Area of Triangle: " + area);      
    }
}

Output:
Area of Triangle: 1005.0

Method-2 : Java Program to Find Area of Triangle Using User Defined Value

In this the values of width and height are dynamic values, means it will ask the user for the input values in the program. So, let’s see the program to understand it more clearly.

import java.util.*;

class Main
{
   public static void main(String args[]) 
    {   
       
       Scanner sc= new Scanner(System.in);
        
        System.out.println("Enter the width of triangle:");
        double width= sc.nextDouble();
 
        System.out.println("Enter the height of triangle:");
        double hight= sc.nextDouble();
 
       //Area = (width*height)/2
       double area=(width*hight)/2;
       System.out.println("Area of triangle: " + area);      
   }
}

Output:

Enter the width of triangle: 2
Enter the height of triangle: 4
Area of triangle: 4.0

Method-3: Java Program to Find Area of Triangle Using Constructor

In this the width and height values will be taken by the user and those values will be passed as parameter to the constructor where the actual area finding logic is present.

So, let’s see the program to understand it more clearly.

import java.util.*;


class TriangleArea
{
      long area;
      // Constructor
      TriangleArea(long width,long hight)
    {
      //finding area
      area=(width*hight)/2;  
    }
}
 
//Driver Class
class Main
{
   public static void main(String args[]) 
    {   
      Scanner sc= new Scanner(System.in);
      // Asking user to take width input
      System.out.println("Enter the width of triangle:");
      long width= sc.nextLong();
      // Asking user to take hight input
      System.out.println("Enter the height of triangle:");
      long hight= sc.nextLong();
      TriangleArea t=new TriangleArea(width,hight);
      System.out.println("Area of triangle: " + t.area);      
   }
}

Output:

Enter the width of triangle: 4
Enter the height of triangle: 4
Area of triangle: 8

Method-4: Java Program to Find Area of Triangle Using User Defined Method

In this the width and height values will be taken by the user and those values will be passed as parameter to a user defined method where the actual area finding logic is present.

So, let’s see the program to understand it more clearly.

import java.util.*;
 
//Driver Class
class Main
{
   public static void main(String args[]) 
    {   
      Scanner sc= new Scanner(System.in);
      // Asking user to take width input
      System.out.println("Enter the width of triangle:");
      long width= sc.nextLong();
      System.out.println("Enter the height of triangle:");
      long hight= sc.nextLong();
      //calling the method
      TriangleArea(width,hight);
    }
     
     //user defined method  
    public static void TriangleArea(long width,long hight)
    {
      long area=(width*hight)/2;  
      System.out.println("Area of triangle: " + area); 
    }
    
}

Output:

Enter the width of triangle: 4
Enter the height of triangle: 4
Area of Triangle: 8

Beginners and experienced programmers can rely on these Best Java Programs Examples and code various basic and complex logics in the Java programming language with ease.

Related Java Programs:

• Java Program to Find Perimeter of Triangle
• Java Program to Find Area and Perimeter of Rectangle
• Java Program to Find Area and Perimeter of Square
• Java Program to Find Area and Circumference of Circle

In this article we are going see how to delete a file by using Java programming language.

Java Program to Delete a File

JavaIO is a package that contains methods to do input and output operations. It helps us with file handling in java.

Java NIO package is also another package that handle IO operations and it might seem a replacement to JavaIO but it is not. Both these packages are used separately.

Let’s see the program to understand it clearly.

• Java Program to Delete a File By Using java.io.File.delete()
• Java Program to Delete a File By Using java.nio.file.files.deleteifexists()

Method-1: Java Program to Delete a File By Using  java.io.File.delete()

Methods Used:

• delete( ) – It is a Boolean method that  deletes the file and then returns 1 if file is successfully deleted else returns 0.

Approach:

• Store the file path in a file object.
• Delete the file using Boolean method delete( ) in java.
• If file was deleted print “file has been deleted”, else print “Unable to delete file”.

Program:

import java.io.*;

public class Main
{
    public static void main(String[] args)
    {
        //object of File class created
        File fi = new File("New Folder/file.docx");
        //Tries to delete the file using java.io delete() function
            if(fi.delete())
            {
                System.out.println("File has been deleted");
            }
            //Executes if file fails to delete
            else
            {
                System.out.println("Unable to delete file");
            }
    }
}

Output:

File has been deleted

Method-2: Java Program to Delete a File By Using java.nio.file.files.deleteifexists()

Methods Used:

• deleteIfExists(path) – It takes the path as parameter and then deletes the file.

Approach:

• We will do it by using a try catch block.
• In the try section use the deleteIfExists( ) function with the file path as parameter.
• In the catch block catch exceptions for things when the file permissions are insufficient and file not existing exception.
• Upon successful deletion print “file has been deleted”.

Program:

import java.io.*;
import java.nio.file.*;

public class Main
{
    public static void main(String[] args)
    {
        try
        {
            // Put the path into the function deleteIfExists()
            Files.deleteIfExists(Paths.get("E:\\New folder (2)\\New folder\\file.docx"));
        }
        // Catch exception if file does not exists
        catch(NoSuchFileException e)
        {
            System.out.println("File does not exist");
        // Catch exception if invalid permissions
        catch(IOException e)
        {
            System.out.println("Invalid Permissions");
        }
        // Prints on successful deletion
        System.out.println("Successfully Deleted");
    }
}

Output:

Successfully Deleted

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In this article we are going to see how we can create and write into a file by using Java programming language.

Java Program to Create a File and Write into the File

As per problem statement first we have to create a file in a specified path then we have to write into the created file.

Let’s see program to understand it clearly.

• Java Program to Create a File and Write into the File by Using Java IO Library
• Java Program to Create a File and Write into the File by Using FileOutputStream
• Java Program to Create a File and Write into the File by Using NIO

Method-1: Java Program to Create a File and Write into the File by Using Java IO Library

In this method we will be using the IO library. We will be creating two objects, one File object to create a new file and another FileWriter object to write into the file.

Approach

• Create a File object with the file name as parameter.
• Use the method createNewFile( ) of the File class to create a new file inside an If block which will print upon successful creation of the file.
• Now create a FileWriter object with the same filename as parameter.
• Write into the file using write( ) method of the FileWriter class.
• Now close the file.
• Use a catch block to catch any IO exceptions and print it.

Program:

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class Main
{
    public static void main(String[] args)
    {
    	//try blockcreateNewFile()
        try
        {
            //Create object of File class and pass file name as parameter
            File fileObj = new File("BtechGeeks.txt");
            //create the file by using inbuilt createNewFile() of File class
            if(fileObj.createNewFile())
            {
                System.out.println("File "+fileObj.getName() +" has been created");
            }

            //Create a writer object to write to the file & pass file name as parameter
            FileWriter writerObj = new FileWriter("BtechGeeks.txt");
            //Writing to the file
            writerObj.write("BtechGeeks is one of the best platform to learn Java");
            writerObj.close();
        }
        //Catch block
        catch(IOException e)
        {
            System.out.println("Unable to complete the task");
            // Print the exception occurred
            e.printStackTrace();
        }
        //Prints on successful creation and writing in the file
        System.out.println("Successfully File Created and Written into File");
    }
}

Output:

Console Output:

File BtechGeeks.txt has been created
Successfully File Created and Written into File

In File Explorer the file has been created:

Written text/content inside file:

Method-2: Java Program to Create a File and Write into the File by Using FileOutputStream

In this method we will be again using the IO library.

Method Used:

• getBytes( ): Convert the string characters into a byte array.
• write( ): Takes byte array as parameter and writes it into the file.

Approach:

• Create a FileOutputStream object with the file name.
• Store the content to write in a string variable
• Convert the string into a byte array using getBytes( ) method.
• Now use the write( ) method of the file class with the byte array as parameter to write into the file.
• Now close the file.

Program:

import java.io.*;

public class Main
{
    public static void main(String[] args)
    {
        //try block
        try
        {
            // Created a FileOutputStream object with the file name as parameter
            FileOutputStream file = new FileOutputStream("file.txt", true);
            // The text to write into the file
            String text = "Hello World";
            // Convert the string into bytes
            byte[] textByte  = text.getBytes();
            // Writing into the file
            file.write(textByte);
            file.close();
            System.out.println("File written successfully");
        }
        //Catch and print any IOException caused
        catch(IOException e)
        {
            System.out.println("Unable to create file. Exception - "+e);
        }
    }
}

Output:

In Console:

File written successfully

In File Explorer:

Method-3: Java Program to Create a File and Write into the File by Using NIO

Java NIO package is also another package that handle IO operations and it  might seem a replacement to JavaIO but it is not. Both IO and NIO packages are used here together.

Approach:

• Store the file path in a string variable
• Now create a Path object to store the path
• Create the file using Files.createFile() method using the path and store its path in another path object
• Print the path of the object to the console
• Now use a FileWriter object with the same path to create an object and write into the file
• Close the file
• Catch any exceptions if caused and print the error

Program:

import java.io.*;
import java.io.*;
import java.nio.file.*;

public class Main{
    public static void main(String[] args)
    {
        //Declare a string variable as assign the file path as value
        String filePath = "C:\\Users\\DELL\\eclipse-workspace\\BtechGeeks_File.txt";
        // Creating a Path object from the file path
        Path path = Paths.get(filePath);
        //try block
        try
        {
            //Creating a file by using createFile() method 
            //and storing its path in a path object p
            Path p = Files.createFile(path);
            // Printing the file path to console
            System.out.println("File created at "+p);

            //Creating a FileWriter object and writing to the file
            FileWriter file = new FileWriter(filePath,true);
            file.write("Hello World");
            file.close();

            System.out.println("Successfully wrote to the file");
        }
        //Catch and print any IOException caused
        catch(IOException e)
        {
            System.out.println("Unable to create file. Exception - "+e);
        }
    }
}

Output:

In Console:

File created at C:\Users\DELL\eclipse-workspace\BtechGeeks_File.txt
Successfully wrote to the file

In File Explorer:

Written text/content in file:

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In this article we will see how you can create and write into CSV file by using Java programming language.

Java Program to Create and Write into CSV File

As per problem statement first we have to create an CSV file and then we have to write data into the file. We will do it without using any third party dependencies. Before jumping into the program let’s know what is CSV file first.

CSV file:

Comma Separated Value in short CSV, it is a file in which information is separated by commas. It can be represented in tabular format as well where each line refers to a data record.

Let’s see the program to understand it clearly.

Approach:

• Create a String 2D array and along with elements(values).
• Create object of File class and pass the CSV file name as parameter.
• Create an object of FileWriter class and pass the File class object as parameter.
• Then write data into file as comma-separated values in each line by using for loop.
• Check the file has been created in the respective path and open it, you will see the data in it.

Program:

package btechgeeks;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class Main 
{
    //Main method
    public static void main(String[] args) throws IOException 
    {
    	//try block
    	try
    	{
    	//declared a String 2D array and its values	
        String[][] users = {
                {"NAME", "AGE", "GENDER", "CITY"},
                {"Satya", "22", "MALE", "Bhubaneswar"},
                {"Rakesh", "26", "MALE", "Chennai"},
                {"Preeti", "21", "FEMALE", "Bokaro"},
                {"Saurav", "25", "MALE", "Noida"},
                {"Richa", "24", "FEMALE", "Bangalore"}
        };

        //Create object of File class and pass the CSV file name as parameter
        File csvFile = new File("StudentDetails.csv");
        //Create an object of FileWriter class and pass the File class object as parameter
        FileWriter fileWriter = new FileWriter(csvFile);

        //Writing data into file
        for (String[] details : users) 
        {
            StringBuilder sb= new StringBuilder();
            for (int i = 0; i < details.length; i++) 
            {
                sb.append(details[i]);
                if (i != details.length - 1) 
                {
                    sb.append(',');
                }
            }
            sb.append("\n");
            fileWriter.write(sb.toString());
        }
        //close the FileWriter class object
        fileWriter.close();
        System.out.println("CSV file created and data written into it successfully");
    	}
    	catch(Exception e)
    	{
    		System.out.println("Exception occured "+ e);
    	}
    }
}

Output:

In Console:

CSV file created and data written into it successfully

In File Explorer:

Created CSV file i.e. StudentDetails.csv

File Opened in Excel

File Opened in Notepad

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In this article we will see how you can detect which number key pressed by suing Java programming language.

Java Program to Detect the Number Key Pressed

As per the problem statement you will allow the user to enter any key and you have to detect that the pressed key is which digit. If user has pressed number keys from 0 to 9 then you have to detect that which number key has been pressed else if any other character key has been pressed then you have to tell ‘What you have entered that is not allowed’. If the user has entered more than one character then tell the user ‘You have entered more than one character’.

Let’s understand it with example.

User has pressed 8 key.
Output: You have pressed 8

User has pressed w key.
Output: What you have entered that is not allowed

User has pressed 5 key & 6 key  means 56
Output: You have entered more than one character

Let’s see the program to understand it more clearly.

Approach:

• Declare an String variable say str.
• Ask the user to enter any character (mostly ask to enter any digit).
• Check if the length of user input value is more than one then print “You have entered more than one character” and return.
• Else convert the String value to Character value and store it in an char type say ch.
• Check the character is a digit or not by using isDigit() method of Character class.
• If that character is a digit then print that number key has been pressed.
• Else print ‘What you have entered that is not allowed’.

Program:

import java.lang.*;
import java.util.*;
public class Main
{
    public static void main(String[] args)
    {
        //Scanner class object created
        Scanner sc=new Scanner(System.in);
        //ask the user to enter any digit
        System.out.println("Enter any digit:  ");
        //assigning the user input digit to a String variable
        String str = sc.next();
        
        //Checking the length of input String
        //If length is more than 1 that means you have entered more than one character
        if (str.length() >1)
        {
            System.out.println("You have entered more than one character"); 
            return;
        }
        
        //converting the String into an character
        char ch=str.charAt(0);
        
        //Checking the character is a digit or not
        boolean result = Character.isDigit(ch);
        
        //if input value is a digit then print the input value
        if(result) 
            System.out.println("You have pressed "+ch);
        //else print Not Allowed 
        else
            System.out.println("What you have entered that is not allowed");
    }
}

Output:

Case-1
Enter any digit: 
6
You have pressed 6

Case-2
Enter any digit: 
h
What you have entered that is not allowed

Case-3
Enter any digit: 
68
You have entered more than one character

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In this article you will see how you can get the size of file by using Java programming language.

Java Program to Get the File Size

Every file which is present in your system occupies some memory space to be stored in the system. File size tells about the amount of memory required for storing that file or in simple the file size is the amount of space taken by the file in the memory.

Let’s see program to understand it more clearly.

• By Using File class length() Method
• By Using FileChannel class size() Method
• By Using Files class size() Method

Method-1: Java Program to Get the File Size by Using File Class length() Method

In Java we have File class in java.io package. File class provides an inbuilt length() method to get the size of the specified file in bytes.

Approach:

• Declare a String variable and assign the file path for which you want to know the file size.
• Create an object of File class by passing file path as parameter.
• Then check specified path or file is actually a file or not by using isFile() method and it is available in the specifies path or not by using exists() method. If that is not a normal file or not available in path then simply return.
• Else get the size of file by using inbuilt length() method.

Program:

import java.io.File;

public class Main
{
    public static void main(String[] args) 
    {
        //declare a String variable filePath and assign the path of file 
        //for which file you want to know the size
        String filePath = "F:\\Tutorial IoT\\SDN Cisco PPT.pdf";
        //Create a object of File class and pass that filePath as parameter
        File file = new File(filePath);
        
        //Check if file does not exist by using inbuilt exists() method
        //or check if file is not a normal file type by using inbuilt isFile() method
        //then return 
        if (!file.exists() || !file.isFile()) 
            return;
        
        //else get the file size by using length() method of File class
        System.out.println("Your File size is: ");
        System.out.println("In Bytes: "+file.length() + " bytes");
        System.out.println("In KiloBytes: "+ file.length() / 1024 + "  kb");
        System.out.println("In MegaBytes: "+file.length() / (1024 * 1024) + " mb");
    }
}

Output:

Your File size is: 
In Bytes: 11261028 bytes
In KiloBytes: 10997 kb
In MegaBytes: 10 mb

Method-2: Java Program to Get the File Size by Using FileChannel Class size() Method

In Java we have FileChannel class in java.nio.channels package. FileChannel class provides an inbuilt size() method to get the size of the specified file in bytes.

Approach:

• Declare a String variable and assign the file path for which you want to know the file size.
• Create an object of Path class by passing file path as parameter.
• Then create an object of FileChannel class by passing object of Path class as parameter.
• Then get the size of file by using inbuilt size() method.

Program:

import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Main
{
    public static void main(String[] args) throws IOException 
    {
        //declare a String variable filePath and assign the path of file 
        //for which file you want to know the size
        String filePath = "F:\\Tutorial IoT\\SDN Cisco PPT.pdf";
        //Create a object of Path class and pass that filePath as parameter
        Path path = Paths.get(filePath);

        //Create an object of FileChannel class and pass the path as parameter
        //Inbuilt open() method returns a filechannel to access the file
        FileChannel fileChannel = FileChannel.open(path);
        //Get the size by using inbuilt size() method of FileChannel class
        long fileSize = fileChannel.size();
        System.out.println("Your file size: "+fileSize + " bytes");
        //Closing the filechannel
        fileChannel.close();
    }
}

Output:

Your file size: 11261028 bytes

Method-3: Java Program to Get the File Size by Using Files Class size() Method

In Java we have Files class in java.nio.file package. Files class provides an inbuilt size() method to get the size of the specified file in bytes.

Approach:

• Declare a String variable and assign the file path for which you want to know the file size.
• Create an object of Path class by passing file path as parameter.
• Then create an object of Files class by passing object of Path class as parameter.
• Then get the size of file by using inbuilt size() method.

Program:

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class Main
{
    public static void main(String[] args) throws IOException 
    {
        //declare a String variable filePath and assign the path of file 
        //for which file you want to know the size
        String filePath = "F:\\Tutorial IoT\\SDN Cisco PPT.pdf";
        //Create a object of Path class and pass that filePath as parameter
        Path path = Paths.get(filePath);
        
        //Get the file size by using inbuilt size() method of File class
        long fileSize = Files.size(path);
        //print the file size
        System.out.println("Your file size: "+fileSize + " bytes");

    }
}

Output:

Your file size: 11261028 bytes

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In this article you will see how to check internet connectivity by using java programming language.

Java Program to Check Internet Connectivity

What is Internet?

Internet refers to the global network means global system of interconnected computer networks. It is also called as network of network. In short we say it only ‘net’. It allows us to connect with any other computer or network devices globally.

What is internet connectivity?

Internet connectivity refers to the technology through which we can connect to any network device and establish a communication with that device. By using computer terminals or network devices you can connect to internet and avail various internet services.

Let’s see the program to understand it more clearly.

• Java Program to Check Internet Connectivity By Using Java URL Class
• Java Program to Check Internet Connectivity By Using Java Runtime Class

NOTE: Please run the program on local machine and not on an online compiler to see the correct output.

Method-1: Java Program to Check Internet Connectivity By Using Java URL Class

Approach:

• Create an object of URL class and pass the web link as parameter
• Check the connection is getting established or not by using openConnection() method of URLConnection class.
• If connection is getting established then Internet is connected else it will throw an exception and catch block will be executed which will print the result as internet is not connected.

Output:

package btechgeeks;

import java.util.*;
import java.io.*;
import java.net.*;

public class CheckInternetConnection 
{
        public static void main(String args[]) throws Exception
        {
        	try 
        	{
        		//Create an object of URL class and pass the web link as parameter
        	        URL obj = new URL("https://www.google.com");
        	        //Check the connection is getting established or not 
        	        //By using openConnection() method of URLConnection class
        	        URLConnection con = obj.openConnection();
        	        con.connect();   
        	 
        	        System.out.println("Internet Connection Available");   
        	            
        	 }
        	//if connection can't be established
        	//then internet is not connected
        	catch (Exception e)
        	{  
        	        System.out.println("No Internet Connection Available");     
        	                                                            
        	} 
        }
}

Output:

Internet Connection Available

Method-2: Java Program to Check Internet Connectivity By Using Java Runtime Class

Approach:

• First get the run time object of running application by using getRuntime() method of Runtime class.
• Check internet connectivity by running a simple ping to OpenDNS’s IP i.e 208.67.222.222.
• You will get an output as 0 if the internet connection is available else you will get 1.
• Them match the output by using an if condition, if the out put is 0 then print ‘Internet is connected’ else print ‘Internet is not connected’.

Output:

package btechgeeks;

import java.util.*;
import java.io.*;

public class CheckInternetConnection 
{
        public static void main(String args[]) throws Exception
        {
        	//By using  getRuntime() method test connectivity
            Process process = java.lang.Runtime.getRuntime().exec("ping -n 1 208.67.222.222");
            int output = process.waitFor();
            //output will be 0 if internet connectivity is available
            if (output == 0) 
            {
                System.out.println("Internet Connected, "
                                   + "Output is " + output);
            }
            //else output will be 1
            else 
            {
                System.out.println("Internet Not Connected, "
                                   + "Output is " + output);
            }
        }
}

Output:

Internet Connected, Output is 0

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In this article we will see how we can generate OTP(One Time Password) by using Java programming language.

Java Program to Generate OTP & Verify OTP

OTP:

One time Password in short known as OTP. It is a random set of numbers or characters which is used for security reason. To check the authentication instantly and correctly of the user, OTP is used where one OTP is shared with the user through any medium like message or mail and then it is validated.

Explanation:

In Java we have java.uti.Random class which is used to generate pseudorandom numbers. We have inbuilt random() method which can be used to generate random numbers.

Let’s see the program to understand it more clearly.

Program to Generate and Verify OTP:

Approach:

• Call a user defined method say createOTP() method by passing length as parameter, which refers to length of OTP. And store the result of this method which is an OTP in a string variable say resultOTP.
• Inside method by using a for loop create the OTP by using Random().nextInt(9) method, which will generate random digit within 0-9.
• After the for loop completion you will get an OTP is which is stored in currentOTP string variable. Return currentOTP
• Then ask the user to enter the system generated OTP and assign it to an String variable say inputOTP.
• Then by using inbuilt equals() method compare both the OTP i.e. system generated OTP and user input OTP.
• If both OTP matches then OTP verification successful else Invalid OTP.

Program:

import java.io.*;
import java.util.*;

public class Main 
{
    static String currentOTP = "";
    static String inputOTP = "";
    static int randomNo;
    
    //driver method
   public static void main(String[] args) 
   {
      //Object of Scanner class created
      Scanner sc=new Scanner(System.in);
      
      //calling the user defined method createOTP() 
      //and passing the OTP length as parameter
      //and assigning the result OTP to a character variable 
      String resultOTP=createOTP(4);
      System.out.println("Your OTP: "+resultOTP);
      
      //Ask the user to enter the OTP
      System.out.print("Enter received OTP: ");
      inputOTP = sc.nextLine();
      if (resultOTP.equals(inputOTP))
        System.out.println("OTP verified successfully");
      else
        System.out.println("Invalid OTP!");
   }

   private static String createOTP(int length) 
   {
        // Use for loop to iterate 4 times and generate random OTP
        for (int i = 0; i < length; i++) 
        {
            //Generating random digit within 0-9, which is of type int
            randomNo = new Random().nextInt(9);
            //converting generated randomNo to type String by using toString() method
            //then concating it to the currentOTP 
            currentOTP = currentOTP.concat(Integer.toString(randomNo));
        }
        //Return the generated OTP
        return currentOTP;
   }
}

Output:

CASE-1: Invalid OTP

Your OTP: 0855
Enter received OTP: 0856
Invalid OTP!

CASE-2: Valid OTP

Your OTP: 7271
Enter received OTP: 7271
OTP verified successfully

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