Merge CSV files into a single file with no repeated headers

Here is an example:

public static void main(String[] args) throws IOException {
    List<Path> paths = Arrays.asList(Paths.get("c:/temp/file1.csv"), Paths.get("c:/temp/file2.csv"));
    List<String> mergedLines = getMergedLines(paths);
    Path target = Paths.get("c:/temp/merged.csv");
    Files.write(target, mergedLines, Charset.forName("UTF-8"));
}

private static List<String> getMergedLines(List<Path> paths) throws IOException {
    List<String> mergedLines = new ArrayList<> ();
    for (Path p : paths){
        List<String> lines = Files.readAllLines(p, Charset.forName("UTF-8"));
        if (!lines.isEmpty()) {
            if (mergedLines.isEmpty()) {
                mergedLines.add(lines.get(0)); //add header only once
            }
            mergedLines.addAll(lines.subList(1, lines.size()));
        }
    }
    return mergedLines;
}

It seems a bit heavyweight to do this in Java. Its trivial in a Linux shell:

(cat FileA ; tail --lines=+2 FileB) > FileC

This should work. It checks if the file being merged have matching headers. Would throw an exception otherwise. Exception handling (to close the streams etc.) has been left as an exercise.

String[] headers = null;
String firstFile = "/path/to/firstFile.dat";
Scanner scanner = new Scanner(new File(firstFile));

if (scanner.hasNextLine())
    headers[] = scanner.nextLine().split(",");

scanner.close();

Iterator<File> iterFiles = listOfFilesToBeMerged.iterator();
BufferedWriter writer = new BufferedWriter(new FileWriter(firstFile, true));

while (iterFiles.hasNext()) {
  File nextFile = iterFiles.next();
  BufferedReader reader = new BufferedReader(new FileReader(nextFile));

  String line = null;
  String[] firstLine = null;
  if ((line = reader.readLine()) != null)
    firstLine = line.split(",");

  if (!Arrays.equals (headers, firstLine))
    throw new FileMergeException("Header mis-match between CSV files: '" +
              firstFile + "' and '" + nextFile.getAbsolutePath());

  while ((line = reader.readLine()) != null) {
    writer.write(line);
    writer.newLine();
  }

  reader.close();
}
writer.close();