[java] How to write new line character to a file in Java

I have a string that contains new lines. I send this string to a function to write the String to a text file as:

    public static void writeResult(String writeFileName, String text)
    {
        try
        {
        FileWriter fileWriter = new FileWriter(writeFileName);
        BufferedWriter bufferedWriter = new BufferedWriter(fileWriter);

        bufferedWriter.write(text);

        // Always close files.
        bufferedWriter.close();

        }
        catch(IOException ex) {
            System.out.println("Error writing to file '"+ writeFileName + "'");}
    } //end writeResult function

But when I open the file, I find it without any new lines. When I display the text in the console screen, it is displayed with new lines. How can I write the new line character in the text file.

EDIT: Assume this is the argument text that I sent to the function above:

I returned from the city about three o'clock on that
may afternoon pretty well disgusted with life.
I had been three months in the old country, and was

How to write this string as it is (with new lines) in the text file. My function write the string in one line. Can you provide me with a way to write the text to the file including new lines ?

EDIT 2: The text is originally in a .txt file. I read the text using:

while((line = bufferedReader.readLine()) != null)
{
sb.append(line); //append the lines to the string
sb.append('\n'); //append new line
} //end while

where sb is a StringBuffer

This question is related to java newline

The answer is


bufferedWriter.write(text + "\n"); This method can work, but the new line character can be different between platforms, so alternatively, you can use this method:

bufferedWriter.write(text);
bufferedWriter.newline();

In EDIT 2:

while((line = bufferedReader.readLine()) != null)
{
  sb.append(line); //append the lines to the string
  sb.append('\n'); //append new line
} //end while

you are reading the text file, and appending a newline to it. Don't append newline, which will not show a newline in some simple-minded Windows editors like Notepad. Instead append the OS-specific line separator string using:

sb.append(System.lineSeparator()); (for Java 1.7 and 1.8) or sb.append(System.getProperty("line.separator")); (Java 1.6 and below)

Alternatively, later you can use String.replaceAll() to replace "\n" in the string built in the StringBuffer with the OS-specific newline character:

String updatedText = text.replaceAll("\n", System.lineSeparator())

but it would be more efficient to append it while you are building the string, than append '\n' and replace it later.

Finally, as a developer, if you are using notepad for viewing or editing files, you should drop it, as there are far more capable tools like Notepad++, or your favorite Java IDE.


SIMPLE SOLUTION

File file = new File("F:/ABC.TXT");
FileWriter fileWriter = new FileWriter(file,true);
filewriter.write("\r\n");

Here is a snippet that gets the default newline character for the current platform. Use System.getProperty("os.name") and System.getProperty("os.version"). Example:

public static String getSystemNewline(){
    String eol = null;
    String os = System.getProperty("os.name").toLowerCase();
    if(os.contains("mac"){
        int v = Integer.parseInt(System.getProperty("os.version"));
        eol = (v <= 9 ? "\r" : "\n");
    }
    if(os.contains("nix"))
        eol = "\n";
    if(os.contains("win"))
        eol = "\r\n";

    return eol;
}

Where eol is the newline


This approach always works for me:

String newLine = System.getProperty("line.separator");
String textInNewLine = "this is my first line " + newLine + "this is my second 
line ";

Split the string in to string array and write using above method (I assume your text contains \n to get new line)

String[] test = test.split("\n");

and the inside a loop

bufferedWriter.write(test[i]);
bufferedWriter.newline();

    PrintWriter out = null; // for writting in file    
    String newLine = System.getProperty("line.separator"); // taking new line 
    out.print("1st Line"+newLine); // print with new line
    out.print("2n Line"+newLine);  // print with new line
    out.close();

Put this code wherever you want to insert a new line:

bufferedWriter.newLine();

The BufferedWriter class offers a newLine() method. Using this will ensure platform independence.