How to merge two csv files with same header columns into another csv file using java

Question

csv file 1:

a|b|c
a|a|a
b|b|b

csv file 2:

a|b|c
c|c|c
d|d|d

output csv file:

a|b|c
a|a|a
b|b|b
c|c|c
d|d|d

here's my code i tried to merge but the header is repeating twice : and when it comes to merging two files into single alternate csv file then also iam facing the same issue as the above the header columns gets repeated everytime what am i supposed to do to ignore it. here's my code below

  public static void main(String[] args) throws IOException  
{ 
    // PrintWriter object for file3.txt 
    PrintWriter pw = new PrintWriter("file3.txt"); 

    // BufferedReader object for file1.txt 
    BufferedReader br1 = new BufferedReader(new FileReader("file1.txt")); 
    BufferedReader br2 = new BufferedReader(new FileReader("file2.txt")); 


    String line1 = br1.readLine(); 
    String line2 = br2.readLine(); 

    // loop to copy lines of  
    // file1.txt and file2.txt  
    // to  file3.txt alternatively 
    while (line1 != null || line2 !=null) 
    { 
        if(line1 != null) 
        { 
            pw.println(line1); 
            line1 = br1.readLine(); 
        } 

        if(line2 != null) 
        { 
            pw.println(line2); 
            line2 = br2.readLine(); 
        } 
    } 

    pw.flush(); 

    // closing resources 
    br1.close(); 
    br2.close(); 
    pw.close(); 

howw to skip the header column in the output file

Answer 1

Just skip the first lines of second and subsequent CSV files:

    for (int i = 0; i < fileNames.length; i++) { 
        System.out.println("Reading from " + fileNames[i]); 

        File f = new File(dir, fileNames[i]);

        BufferedReader br = new BufferedReader(new FileReader(f));

        String line = br.readLine();
        if (i > 0) 
              line = br.readLine(); //just skip the first line

        while (line != null) {
            pw.println(line); 
            line = br.readLine(); 
        } 

        pw.flush(); 
    }