Issue with multiple files merging into 1

Question

I'm trying to write some code that will read the contents of multiple files in a directory then output it into a single file. However when I try to open the files via a for loop it does not recognise the variable I have assigned for the filename:
FileReader fr = new FileReader(fileName);
please see the full program so far, it isn't finished and this currently has me beat, any help would be greately appreciated.
Thanks
Chris
import java.io.*;
public class OutputCCFile
          public static void main(String []args)
               File absolutePath = new File("C:\\java\\Credit Cards");     
               String[] ccFiles = absolutePath.list();
               try
                    boolean newFile = false;
                    CCHeaderLine cch = new CCHeaderLine();
                    String strDate = cch.getDate();
                    String headerLine = cch.getHeader();
                    File file = new File("TUHCC_"+strDate);
                    FileWriter fw = new FileWriter(file);
                    fw.write(headerLine);
                    fw.flush();
                    fw.close();          
               }catch(IOException e) {}
               for (int i = 0; i<ccFiles.length;i++)
                         String filename = ccFiles;
                         filename.toUpperCase();
                         if (filename.startsWith("C")) //only want to open files beginning with C
                                   FileReader fr = new FileReader(fileName);
/*Exception in thread "main" java.lang.Error: Unresolved compilation problem:
     fileName cannot be resolved */
                                   BufferedReader br = new BufferedReader(fr);
                                   String dataLine = br.readLine();

Answer 1

String filename = ccFiles;
filename.toUpperCase();
if (filename.startsWith("C")) //only want to open files beginning with C
FileReader fr = new FileReader(fileName);
There are several problems here.
1) Variable names (and many other things) are case sensitive in Java. filename != fileName
2) filename.toUpperCase(); will not change filename, it will just determine its upper case version and discard it