What is the best way to iterate over the lines of a Java String?

Question

Currently I\'m using something like :

String[]lines = textContent.split(System.getProperty(\"line.separator\"));
for(String tmpLine : lines){
   //do somethi         


        

Answer 1

You could use :

BufferedReader bufReader = new BufferedReader(new StringReader(textContent));

And use the readLine() method :

String line=null;
while( (line=bufReader.readLine()) != null )
{

}

Answer 2

To add the Java 8 way to this question:

Arrays.stream(content.split("\\r?\\n")).forEach(line -> /*do something */)

Of curse you can also use System.lineSeparator()to split if you are sure that the file is comming from the same plattform as the vm runs on.

Or even better use the stream api even more agressiv with filter, map and collect:

String result = Arrays.stream(content.split(System.lineSeparator()))
                     .filter(/* filter for lines you are interested in*/)
                     .map(/*convert string*/)
                     .collect(Collectors.joining(";"));

Answer 3

Combine java.io.StringReader and java.io.LineNumberReader

Answer 4

You can actually wrangle Scanner to allow you to use a normal for loop:

import java.util.Scanner;
public class IterateLines {
    public static void main(String[] args) {
        Iterable<String> sc = () ->
            new Scanner("foo bar\nbaz\n").useDelimiter("\n");
        for (String line: sc) {
            System.out.println(line);
        }
    }
}

gives us:

$ javac IterateLines.java && java IterateLines 
foo bar
baz