如何在Java中将每一行写到新行？

Question

I have written a method that prints out the arrayList into a text file, but for some reason it does not print on a new line each time, it prints everything onto a single line. below is my code.

private static void writingToFile() {
        try {
            BufferedWriter writeArrayList = new BufferedWriter (new FileWriter("D:\\text.txt"));
            for(StoreCommands s : commandsList){
                writeArrayList.write(s + "\n");
            }
            writeArrayList.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

Also at the moment I have to enter path in manually, I want the user to choose where they want to place the file, how can i do that as well? thanks.

Answer 1

To append on a file, create with :

new FileWriter("D:\\text.txt", true);

FileWriter public FileWriter(String fileName, boolean append) throws IOException Constructs a FileWriter object given a file name with a boolean indicating whether or not to append the data written.

Parameters fileName - String The system-dependent filename. append - boolean if true, then data will be written to the end of the file rather than the beginning. Throws IOException if the specified file is not found or if some other I/O error occurs. More here

Other example :

        FileOutputStream fileOutput = new FileOutputStream("myfile.txt", true);
        BufferedOutputStream bufferedOutput = new BufferedOutputStream(
                fileOutput);

        bufferedOutput.write(<your binaries here>);

Answer 2

How about trying something like this

private static void writingToFile() {
    try {
        PrintWriter out = new PrintWriter (new FileWriter("D:\\text.txt"));
        for(StoreCommands s : commandsList){
            out.println(s);
        }
        out.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

I prefer PrintWriter because I like the println method. You can add System. before all your statements and print instead of writing to file.

Edit, also I'm assuming your calling the String correctly. You might instead need something like

        for(StoreCommands s : commandsList){
            out.println(s.toString());
        }

Lastly for fun Java8 version

private static void writeToFile(){
    try(PrintWriter out = new PrintWriter(new FileWrite("test.txt"))){
        list.stream().map(StoreCommands::toString).forEach(s -> out.println(s));
        out.close();
    } catch (IOException ex){
        System.err.out(ex);
    }
}

Answer 3

For writing new lines, check out the newLine() method of the BufferedWriter class.

For reading user input, you can use the basic Scanner class as follows:

Scanner get = new Scanner(System.in);
String path = get.nextLine();
...

Answer 4

Question #1:

Change "\\n" to "\\r\\n"

Question #2 :

Follow the answer posted by CB , and give him/her a vote-up for it (if possible)...

Answer 5

To answer your question about not having to hard code a file path, try using command line arguments, like this (in your class):

public static void main(String[] args){
...
writingToFile(args[0]);

Then when you run the java app you would just specify the File name on the command line like this:
java <classname>.java D:/text.txt