Appending One File to Another in Java - Why Does My Code Overwrite?

I'm a moderately-experienced C++ guy learning Java and having a great time learning on this website. Recently, I did some research on how Java can append one file to another. Suppose I have two files. Here's C:\tmp\permFile.txt: ``` Line A: abcef Line B: ghijk Line C: lmnop ``` And here's C:\tmp\tmpFile.txt: ``` line 1: 1234567890 line 2: 0123456789 line 3: 9012345678 line 4: 8901234567 ``` The objective here is simple; I want to append tmpFile.txt to the end of permFile.txt. I researched code to do this and thought I had the problem solved. Only today I noticed that permFile.txt looks like this after running the code: ``` Line A: abcef Line B: ghijk Line C: lmnop: 9012345678 line 4: 8901234567 ``` I think what is happening here is permFile is 48 characters long (16 chars/line). My code counts exactly 48 chars into tmpFile and appends from the 49th character on out. Weird, huh? Here's the code: ``` import java.io.*; public class myProgram { public static void main(String[] args) throws IOException { // Define two filenames: String permFile = "C:\tmp\permFile.txt"; String tmpFile = "C:\tmp\tmpFile.txt"; appendFiles appender = new appendFiles(permFile, tmpFile); } } public class appendFiles { public static void appendFiles(String permFile, String tmpFile) throws IOException { // Appends file "tmpFile" to the end of "permFile" // Code adapted from: https://www.daniweb.com/software-development/java/threads/44508/appending-two-java-text-files try { // create a writer for permFile BufferedWriter out = new BufferedWriter(new FileWriter(permFile, true)); // create a reader for tmpFile BufferedReader in = new BufferedReader(new FileReader(tmpFile)); String str; while ((str = in.readLine()) != null) { out.write(str); } in.close(); out.close(); } catch (IOException e) { } } } ``` What I suspect I need to do is add a line which "points" the "out" BufferedWriter to the END of permFile, not the beginning. But my attempts to do this have been disastrous and not worth detailing here. Also, what I don't get is why the contents of tmpFile do not overwrite all of permFile if "out" is pointed at the start of permFile. Suspect I'm making a simple, rookie mistake. Many thanks! -P PS - Can't tell you how much I love this site. I always try to research my own solutions, but when you get stuck on a specific problem, there's no substitute to asking real people for help.