Question

I am having an annoying problem that I cannot seem to fix. I have a class named DirFormMgmt which manages two files; directories.txt and formats.txt. The problem is that when I instantiate an instance of this class when the program starts it clears everything that was in the files before it started, so for instance if I open the formats.txt file and type in “.avi” and run the program the text file will become blank. Here is the only code I have running in my class to isolate the issue and I am unsure of why this is happening:

At the top of my class I declare:

File dirFile = new File("directories.txt");
File formatFile = new File("formats.txt");
private BufferedReader dirReader;
private BufferedWriter dirWriter;
private BufferedReader formatReader;
private BufferedWriter formatWriter;

The constructor:

public DirFormMgmt() throws IOException {
     checkFileExistence();
     initReaderWriter();
}

The two methods called by the constructor:

public void checkFileExistence() throws IOException {
     if (!dirFile.exists()) {
         dirFile.createNewFile();
     }
     if (!formatFile.exists()) {
         formatFile.createNewFile();
     }   
}

and:

public void initReaderWriter() throws IOException {
     dirReader = new BufferedReader(new FileReader(dirFile));
     dirWriter = new BufferedWriter(new FileWriter(dirFile));

     formatReader = new BufferedReader(new FileReader(formatFile));
     formatWriter = new BufferedWriter(new FileWriter(formatFile));
}

I checked to see if the createNewFile() methods were being called but they were not, so the problem must be with my initReaderWriter() method, but I am unsure of what is wrong, any help is greatly appreciated!

Answer 1

Use new FileWriter(file, true) to append content to an existing file. Otherwise, the contents will be overwritten.