A **comma-separated values (CSV)** file is a plain text file that is used to arrange tabular data and is typically found in spreadsheets or databases. CSV files are frequently used as they are accessible in Microsoft Excel, it is very easy to parse data from them, and their data can be imported into a database. 

# Basic Structure of CSV files
CSV files store data in a particular format where commas separate each data item.

```HTML
  Column 1   ,   Column 2   , Column 3 ...
Row 1 Data 1 , Row 1 Data 2 , Row 1 Data 3 ...
Row 2 Data 1 , Row 2 Data 2 , Row 2 Data 3 ...

```

The first row represents the name of the column, and each following row represents the data. 

> Note: The most frequently used delimiter is a comma. However, other delimiters such as colons, semi-colons, etc. may also be used. 

# Parse CSV files in Java
In Java, there are multiple ways of reading and parsing CSV files. The most common ones are:
- Using java.util.Scanner
- Using String.split() function
- Using 3rd Party libraries like OpenCSV

In this shot, we will be only looking at the first two methods as they involve built-in libraries.




## 1. Using java.util.Scanner
A Scanner in Java can be used to break the input into tokens using delimiters. These tokens are then converted into values of different types using various next-methods.

To use this method, we first need to import the Scanner using the statement​ `import java.util.Scanner`.


Name, Age, Department
John, 26, Accounts
Mike,  30, HR
James, 29, IT
Oliver,32, IT

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
 
public class main
{
    public static void main(String[] args) throws FileNotFoundException
    {
        //Get scanner instance
        Scanner scanner = new Scanner(new File("CSVFile.csv"));
         
        //Set the delimiter used in file
        scanner.useDelimiter(",");
         
        //Get all tokens and store them in some data structure
        while (scanner.hasNext())
        {
            System.out.print(scanner.next() + " |");
        }
        scanner.close();
    }
}

## 2. Using String.split() function

The `String.split()` function in Java takes tokens from the given string and turns them into tokens that are based on a provided delimiter as a parameter.



import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
 
public class main
{
    public static void main(String[] args)
    {
        //Input file which needs to be parsed
        String fileToParse = "CSVFile.csv";
        BufferedReader fileReader = null;
         
        //Delimiter used in CSV file
        final String DELIMITER = ",";
        try
        {
            String line = "";
            fileReader = new BufferedReader(new FileReader(fileToParse));
             
            //Read the file line by line
            while ((line = fileReader.readLine()) != null)
            {
                //Get all tokens available in line
                String[] tokens = line.split(DELIMITER);
                for(String token : tokens)
                {
                    System.out.print(token + " | ");
                }
                System.out.println(" ");
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        finally
        {
            try {
        fileReader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

How to parse a CSV file in Java

CSV files store tabular data separated by commas. Java parsers include Scanner for tokenization and String.split() for delimiter-based splitting.