Read and write CSV file

Read and write CSV file, this code read one csv file and then for each four lines, it does a transpose, and then save the results.
java code

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package commandssvn;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 *
 * @author samy
 */
public class WriteCSV1 {
    
    public static void main(String[] args) throws IOException {
         generateCsvFile();
         run();
        
    }
    public static void run() {

        String csvFile = "d:/Files_Data2/Results3.csv";
        String[][] arrayStrings=new String[4][6];
        
        BufferedReader br = null;
        String line = "";
        String cvsSplitBy = ",";
         

        try {

           

            br = new BufferedReader(new FileReader(csvFile));
         
          
            boolean firstTime=false;
            int i=0;
            while ((line = br.readLine()) != null) {
                 firstTime=false;
                 
                arrayStrings[i] = line.split(cvsSplitBy);
                
                i++;
                if(i==4)
                {
                    i=0;
                    generateCsvFile(arrayStrings);
                }
           
            }



        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

         
    }
    
    
    private static void generateCsvFile()
   {
	try
	{
	    FileWriter writer = new FileWriter("D:/xyu.csv",false);
 
            writer.append(" ");
	    writer.append(',');
            
	    writer.append("Estimate");
	    writer.append(',');
	    writer.append("StdError");
            	    writer.append(',');
	    writer.append("zValue");
            	    writer.append(',');
	    writer.append("Prz");
            writer.append('\n');
            
            
	    //generate whatever data you want
 
	    writer.flush();
	    writer.close();
	}
	catch(IOException e)
	{
	     e.printStackTrace();
	} 
    }
    
    
     private static void generateCsvFile(String[][] values)
   {
	try
	{
	    FileWriter writer = new FileWriter("D:/xyu.csv",true);
 
             
	    writer.append("Intersect");
	    writer.append(',');
            
            writer.append(values[0][1]);
	    writer.append(',');
            writer.append(values[1][1]);
	    writer.append(',');
            writer.append(values[2][1]);
	    writer.append(',');
            writer.append(values[3][1]);
	    writer.append(','); 
            writer.append(values[1][5]);
	   
            
            writer.append('\n');
            
	    writer.append("NewFeatures");
            writer.append(',');
                    
               writer.append(values[0][2]);
	    writer.append(',');
            writer.append(values[1][2]);
	    writer.append(',');
            writer.append(values[2][2]);
	    writer.append(',');
            writer.append(values[3][2]);
	    writer.append(','); 
            writer.append(values[1][5]);
	   
                       
                    
                    
            writer.append('\n');        
                    
	    writer.append("Improvements");
            writer.append(',');
                writer.append(values[0][3]);
	    writer.append(',');
            writer.append(values[1][3]);
	    writer.append(',');
            writer.append(values[2][3]);
	    writer.append(',');
            writer.append(values[3][3]);
	    writer.append(','); 
            writer.append(values[1][5]);
	   
            
            writer.append('\n');
            
	    writer.append("SqrCommits");
            writer.append(',');
            writer.append(values[0][4]);
	    writer.append(',');
            writer.append(values[1][4]);
	    writer.append(',');
            writer.append(values[2][4]);
	    writer.append(',');
            writer.append(values[3][4]);
	    writer.append(','); 
            writer.append(values[1][5]);
	    	      
	    writer.append('\n');
          
	    //generate whatever data you want
 
	    writer.flush();
	    writer.close();
	}
	catch(IOException e)
	{
	     e.printStackTrace();
	} 
    
   }
}

Why did the result becomes like this

/* * To change this template, choose Tools | Templates * and open the template in the editor. */package commandssvn;import java.io.BufferedReader;import java.io.FileNotFoundException;import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;/** * * @author samy */public class WriteCSV1 { public static void main(String[] args) throws IOException { generateCsvFile(); run(); } public static void run() { String csvFile = "d:/Files_Data2/Results3.csv"; String[][] arrayStrings=new String[4][6]; BufferedReader br = null; String line = ""; String cvsSplitBy = ","; try { br = new BufferedReader(new FileReader(csvFile)); boolean firstTime=false; int i=0; while ((line = br.readLine()) != null) { firstTime=false; arrayStrings[i] = line.split(cvsSplitBy); i++; if(i==4) { i=0; generateCsvFile(arrayStrings); } } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } finally { if (br != null) { try { br.close(); } catch (IOException e) { e.printStackTrace(); } } } } private static void generateCsvFile() { try { FileWriter writer = new FileWriter("D:/xyu.csv",false); writer.append(" "); writer.append(','); writer.append("Estimate"); writer.append(','); writer.append("StdError"); writer.append(','); writer.append("zValue"); writer.append(','); writer.append("Prz"); writer.append('\n'); //generate whatever data you want writer.flush(); writer.close(); } catch(IOException e) { e.printStackTrace(); } } private static void generateCsvFile(String[][] values) { try { FileWriter writer = new FileWriter("D:/xyu.csv",true); writer.append("Intersect"); writer.append(','); writer.append(values[0][1]); writer.append(','); writer.append(values[1][1]); writer.append(','); writer.append(values[2][1]); writer.append(','); writer.append(values[3][1]); writer.append(','); writer.append(values[1][5]); writer.append('\n'); writer.append("NewFeatures"); writer.append(','); writer.append(values[0][2]); writer.append(','); writer.append(values[1][2]); writer.append(','); writer.append(values[2][2]); writer.append(','); writer.append(values[3][2]); writer.append(','); writer.append(values[1][5]); writer.append('\n'); writer.append("Improvements"); writer.append(','); writer.append(values[0][3]); writer.append(','); writer.append(values[1][3]); writer.append(','); writer.append(values[2][3]); writer.append(','); writer.append(values[3][3]); writer.append(','); writer.append(values[1][5]); writer.append('\n'); writer.append("SqrCommits"); writer.append(','); writer.append(values[0][4]); writer.append(','); writer.append(values[1][4]); writer.append(','); writer.append(values[2][4]); writer.append(','); writer.append(values[3][4]); writer.append(','); writer.append(values[1][5]); writer.append('\n'); //generate whatever data you want writer.flush(); writer.close(); } catch(IOException e) { e.printStackTrace(); } }}

what extension name should be use?

csv files.