If the string was constructed in the same program, I would recommend using this:
String newline = System.getProperty("line.separator");
boolean hasNewline = word.contains(newline);
But if you are specced to use \n, this driver illustrates what to do:
class NewLineTest {
public static void main(String[] args) {
String hasNewline = "this has a newline\n.";
String noNewline = "this doesn't";
System.out.println(hasNewline.contains("\n"));
System.out.println(hasNewline.contains("\\n"));
System.out.println(noNewline.contains("\n"));
System.out.println(noNewline.contains("\\n"));
}
}
Resulted in
true
false
false
false
In reponse to your comment:
class NewLineTest {
public static void main(String[] args) {
String word = "test\n.";
System.out.println(word.length());
System.out.println(word);
word = word.replace("\n","\n ");
System.out.println(word.length());
System.out.println(word);
}
}
Results in
6
test
.
7
test
.
The second one:
word.contains("\n");
I'd rather trust JDK over System property. Following is a working snippet.
private boolean checkIfStringContainsNewLineCharacters(String str){
if(!StringUtils.isEmpty(str)){
Scanner scanner = new Scanner(str);
scanner.nextLine();
boolean hasNextLine = scanner.hasNextLine();
scanner.close();
return hasNextLine;
}
return false;
}
For portability, you really should do something like this:
public static final String NEW_LINE = System.getProperty("line.separator")
.
.
.
word.contains(NEW_LINE);
unless you're absolutely certain that "\n" is what you want.
Source: Stackoverflow.com