I need a help to generate new file

Question

Hi Guys
I need your help. I have two text box in my form, the first one takes the file name to read, and then when user type in another file name in the second textbox, result should be saved as a typed file name in the same path.
What I really want to do is, when the file is exist already (for instance, I'll name it as result.txt), my program scan through the result.txt file and append the new data at the end of the file. But result.txt file doesn't exist, it has to generate new file and save the data into the new one. I think I need to implement these in the OpenFile1() function, but I dont' know how.
Does anybody have idea to solve this?
private void saveFile() {
textArea.append("SAVE FILE\n---------\n");
if (openFile1())
     try {
          outputToFile();
catch (IOException ioException) {
          JOptionPane.showMessageDialog(this,"Error Writing to File",
               "Error",JOptionPane.ERROR_MESSAGE);
private boolean openFile1 ()
     // Display file dialog box
title=textfield1.getext();
path=fileName_in.getPath();
     File file_out = new File(path, title);
if (fileName_out == null || fileName_out.getName().equals("")) {
     JOptionPane.showMessageDialog(this,"Invalid File name",
               "Invalid File nmae",JOptionPane.ERROR_MESSAGE);
     return(false);
     else {
try
boolean created = file_out.createNewFile();
if(true)
fileOutput = new PrintWriter(new FileWriter(fileName_out));
return(true);
else
catch (IOException exc) {
System.err.println("# Error: " );
private void outputToFile() throws IOException
// Initial output
     textArea.append("File name = " + fileName_out + "\n");
     //process();
     // Test if data exists
     if (data != null)
     Date now = new Date();
DateFormat df = DateFormat.getDateInstance(DateFormat.SHORT);
String s = df.format(now);
//long nowlong=now.getTime();
fileOutput.println(s);
fileOutput.print(fileName_in.getName() +" of slope value:" + slope);
textArea.append("File output complete\n\n");
     else
textArea.append("No data\n\n");
     // End by closing file
     fileOutput.close();
Thank you so much!

Answer 1

There's a lot of unnecessary code there, and anyway it isn't formatted in a readable way so I am not going to look too closely at it. But if you want to append to the file if it already exists and create the file if it doesn't, then all you need is this: fileOutput = new PrintWriter(new FileWriter(fileName_out, true));Note the "true" parameter there which (if you look in the API documentation) says that new data will be appended at the end of the file.