Extract csv values into key value pairs

I have a CSV file with two columns; ColumnA and ColumnB. I want to extract both values of ColumnA and ColumnB to parse them later in a for loop.

Example of CSV:

John, John Smith
James, James Bond

My program extracts successfully ColumnA when I make a system print of the variable oldName. However, I do not know how to extact the value of ColumnB, and I think the reason is the data structure I have chosen, which I do not know how to correctly adapt for my needs?

Basically, I want for my for loop that the variable oldName = "John" and newName = "John Smith" for the first iteration, and for the second oldName = "James" and newName = "James Bond" etc.

String fName = "TestFile.csv";
String thisLine; 
FileInputStream fis = new FileInputStream(fName);
DataInputStream myInput = new DataInputStream(fis);
String oldName;
String newName;
int i=0; 

String[] GroupArray = new String[1000]; 
while ((thisLine = myInput.readLine()) != null)
{
	String strar[] = thisLine.split(",");
	
for(int j=0;j<strar.length;j++)
{
if(i!=0)
{
GroupArray[i] = strar[j];
}
else
{
GroupArray[i] = strar[j];
}
} 
i++;
} 
   try{	
	for (int l = 0; l < i; l++)
	{
		oldName = GroupArray[0];
		newName = GroupArray[1];
        out.println ("User: "+ oldName +" has been renamed to: "+ newName +"<BR>");

You were on the right track but you had some superfluous code. Note that DataInputStream#readLine is deprecated, thus I used BufferedReader#readLine.

String filename = "/path/to/your/file";
File csv = new File(filename);
BufferedReader reader = new BufferedReader(new FileReader(csv));

String[] groupArray = new String[1000];

String line;
int i = 0;
while((line = reader.readLine()) != null) {
	String[] split = line.split(",");
	
	groupArray[i] = split[0].trim();
	groupArray[i+1] = (split.length > 1) ? split[1].trim() : "";
	
	i += 2;
}

String oldName, newName;
for(int j = 0; j < i; j += 2) {
	oldName = groupArray[j];
	newName = groupArray[j+1];
	System.out.println ("User: "+ oldName +" has been renamed to: "+ newName +"<BR>");
}

Input:

John, John Smith
James, James Bond

Ouput:

User: John has been renamed to: John Smith<BR>
User: James has been renamed to: James Bond<BR>

I think you are overcomplicating the task without need. The following example should serve as a starting point:

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class Test {

    public static void main(String[] args) throws IOException {
        File file = new File("TestFile.csv");
        BufferedReader br = new BufferedReader(new FileReader(file));

        String line;
        List<String[]> allLines = new ArrayList<>();
        while ((line = br.readLine()) != null) {
            String[] splited = line.split("\\s*,\\s*");
            allLines.add(splited);                
        }
        
        for(String[] row : allLines){
            String oldName = row[0];
            String newName = row[1];
            System.out.println ("User: "+ oldName +" has been renamed to: "+ newName );
        }
    }
}