Java 13 Triple-quote Text Block *WITHOUT* newlines

You can use String.lines introduced since Java-11 as:

String output = paragraph.lines().collect(Collectors.joining());

A complimentary and for what's worth it, here is a screenshot from JShell execution of the two different blocks of code:

The designers of this feature realized this requirement as well (see 'New escape sequences' in JEP368). So, with the latest early access build for JDK 14 you can use a trailing \ to escape the new line at the end of a line:

public class Main {
    public static void main(String[] args) {
        String paragraph =
            """
            aaaa bbbb cccc \
            dddd eeee ffff \
            gggg hhhh iiii \
            """;
        System.out.println(paragraph);
    }
}

Prints:

aaaa bbbb cccc dddd eeee ffff gggg hhhh iiii