Split Java String by New Line

Question

I\'m trying to split text in a JTextArea using a regex to split the String by \\n However, this does not work and I also tried by \\r\\n|\\r|

Answer 1

In JDK11 the String class has a lines() method:

Returning a stream of lines extracted from this string, separated by line terminators.

Further, the documentation goes on to say:

A line terminator is one of the following: a line feed character "\n" (U+000A), a carriage return character "\r" (U+000D), or a carriage return followed immediately by a line feed "\r\n" (U+000D U+000A). A line is either a sequence of zero or more characters followed by a line terminator, or it is a sequence of one or more characters followed by the end of the string. A line does not include the line terminator.

With this one can simply do:

Stream<String> stream = str.lines();

then if you want an array:

String[] array = str.lines().toArray(String[]::new);

Given this method returns a Stream it upon up a lot of options for you as it enables one to write concise and declarative expression of possibly-parallel operations.

Answer 2

As an alternative to the previous answers, guava's Splitter API can be used if other operations are to be applied to the resulting lines, like trimming lines or filtering empty lines :

import com.google.common.base.Splitter;

Iterable<String> split = Splitter.onPattern("\r?\n").trimResults().omitEmptyStrings().split(docStr);

Note that the result is an Iterable and not an array.

Answer 3

package in.javadomain;

public class JavaSplit {

    public static void main(String[] args) {
        String input = "chennai\nvellore\ncoimbatore\nbangalore\narcot";
        System.out.println("Before split:\n");
        System.out.println(input);

        String[] inputSplitNewLine = input.split("\\n");
        System.out.println("\n After split:\n");
        for(int i=0; i<inputSplitNewLine.length; i++){
            System.out.println(inputSplitNewLine[i]);
        }
    }

}

Answer 4

All answers given here actually do not respect Javas definition of new lines as given in e.g. BufferedReader#readline. Java is accepting \n, \r and \r\n as new line. Some of the answers match multiple empty lines or malformed files. E..g. <sometext>\n\r\n<someothertext> when using [\r\n]+would result in two lines.

String lines[] = string.split("(\r\n|\r|\n)", -1);

In contrast, the answer above has the following properties:

• it complies with Javas definition of a new line such as e.g. the BufferedReader is using it
• it does not match multiple new lines
• it does not remove trailing empty lines

Answer 5

For preserving empty lines from getting squashed use:

String lines[] = String.split("\\r?\\n", -1);

Answer 6

The above answers did not help me on Android, thanks to the Pshemo response that worked for me on Android. I will leave some of Pshemo's answer here :

split("\\\\n")