Java 13 Triple-quote Text Block *WITHOUT* newlines

Question

The Java 13 multi line text block facility with """ delimiters is becoming well known.

However I have a recurring need where I need entire paragraphs without the embedded newlines.

In other words, the following code snippet:

String paragraph =
    """
    aaaa bbbb cccc
    dddd eeee ffff
    gggg hhhh iiii
    """;
System.out.println(paragraph);

produces the following, as you'd expect:

aaaa bbbb cccc
dddd eeee ffff
gggg hhhh iiii

...which is usually tremendously useful. However in my case, for particularly large paragraphs I need it to produce this:

aaaa bbbb cccc dddd eeee ffff gggg hhhh iiii

(....and deal with text flow later.)

Is there a way to establish a "no-newline" parameter for the triple-quote feature?

Answer 1

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

Answer 2

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:

Answer 3

Indeed, finding a good answer in Java 13 is not easy (maybe even impossible) but I think Jorn Vernee addressed the concern gracefully in his reply (new escape sequences in Java 14 provide an acceptable solution).

To expand on several listed concerns:

• Holger mentions "the 'text blocks' feature is not very convincing". I have seen a lot of "ugly" code that does artificial string concatenation, so I think the feature definitely addresses an issue. On the other side, I have to agree that a feature like this leaves a lot of room for abuse (as in "let us put a lot of text in the Java code because now we can nicely do it!" - see the next point).
• The original question mentions "large paragraphs" which make me advise not using this feature at all, but externalizing that content to resource files.
• About the clarity and that certain aspects "are not obvious to the reader, so we have a syntax with a non-obvious meaning". That is partly correct, and it takes some reading and experimentation while the available material is not that vast at this moment. I found this: Programmer's Guide To Text Blocks, which provides quite a lot of examples. I also authored some examples, the one on text blocks being here: TextBlocks.java.

(Let's not forget that text blocks are in 'second preview' mode).