Java – How to get a new line character or \n?

By mkyong | Updated: July 21, 2020

Viewed: 16,788 (+64 pv/w)

Tags: java java.io line separator new line write file

The newline character, also called end of line (EOL), line break, line feed, line separator or carriage return, is a control character to tell the end of a line of text, and the next character should start at a new line. On the Windows system, it is \r\n, on the Linux system, it is \n.

In Java, we can use System.lineSeparator() to get a platform-dependent new line character.

package com.mkyong.io.howto;

public class GetNewLine {

    public static void main(String[] args) {

        System.out.print("Line 1");

        // Windows \r\n, Linux \n
        System.out.print(System.lineSeparator());

        System.out.print("Line 2");

    }
}

Output

Line 1
Line 2

P.S The System.getProperty("line.separator") also returns the same result.

1. System.lineSeparator()

Here’s the System.lineSeparator() method signature, available since Java 1.7, read the comments.

package java.lang;

public final class System {

  /**
   * Returns the system-dependent line separator string.  It always
   * returns the same value - the initial value of the {@linkplain
   * #getProperty(String) system property} {@code line.separator}.
   *
   * <p>On UNIX systems, it returns {@code "\n"}; on Microsoft
   * Windows systems it returns {@code "\r\n"}.
   *
   * @return the system-dependent line separator string
   * @since 1.7
   */
  public static String lineSeparator() {
      return lineSeparator;
  }

2. Print a newline character

If we want to print a platform-dependent new line character, try %n (line separator) in String.format.

package com.mkyong.io.howto;

public class GetNewLine2 {

    public static void main(String[] args) {

        System.out.print(String.format("%s%n%s", "Line 1", "Line 2"));

    }
}

Output

Line 1
Line 2

3. Write a newline character

If we use BufferedWriter to write text to a file, the newLine() represents the platform-dependent newline character.

package com.mkyong.io.howto;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

public class GetNewLine3 {

    public static void main(String[] args) {

        // write a new line character
        String fileName = "/home/mkyong/sample.txt";

        List<String> content = Arrays.asList("A", "B", "C");

        try (BufferedWriter bw = new BufferedWriter(new FileWriter(fileName))) {

            for (String t : content) {
                bw.write(t);
                bw.newLine();
                // same
                //bw.write(System.lineSeparator());
            }

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


    }
}

Review the newLine() method signature, internally, the BufferedWriter also use System.lineSeparator().

package java.io;

public class BufferedWriter extends Writer {
    /**
     * Writes a line separator.  The line separator string is defined by the
     * system property {@code line.separator}, and is not necessarily a single
     * newline ('\n') character.
     *
     * @exception  IOException  If an I/O error occurs
     */
    public void newLine() throws IOException {
        write(System.lineSeparator());
    }

    //...
}

Download Source Code

References

• System.lineSeparator()
• String.format
• Formatter JavaDoc
• BufferedWriter JavaDoc