Errata OCP study guide JSE 11 Programmer II, question 10 chapter 9.

[Nicholas Barbosa]

Hi,

Using APPEND, if the target file already exists, the contents of source file will be append to the end of target file and if the target not exists will be thrown an exception.

Making letter C and E correct.

Img -> https://ibb.co/N7T7Y04

[Paul Clapham]

Are you simply asserting that an exception will be thrown, or do you have some evidence for that statement?

(By the way: when you make a post, isn't there an "Attachments" tab at the bottom of the box where you type your post? Using that would be much preferred compared to making readers go to some other site.)

[Nicholas Barbosa]

Paul Clapham wrote:Are you simply asserting that an exception will be thrown, or do you have some evidence for that statement?

(By the way: when you make a post, isn't there an "Attachments" tab at the bottom of the box where you type your post? Using that would be much preferred compared to making readers go to some other site.)

Yes!

public static void main(String[] args) {
		try (var source = Files.newBufferedReader(Path.of("C:\\Users\\a.txt"));
				var target = Files.newBufferedWriter(Path.of("C:\\Users\\b.txt"),
						StandardOpenOption.APPEND)) {

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

If "target" not exists, an exception will be thrown. In case you haven't tested the photo code, here is a problem related to APPEND enum value in the stackoverflow.

Stackoverflow->https://stackoverflow.com/questions/30908816/java-nio-file-nosuchfileexception-why-nio-not-creating-file

Excerpt from the stackoverflow response that proves that the letter C is correct and not B, "You're using StandardOpenOption.APPEND, but that won't create a file; it will append to an existing file."

[Paul Clapham]

Yes, the answer you posted goes on to say "The APPEND option creates the file if it does not exist" but that appears to be false. The documentation for APPEND certainly doesn't say that and the Stack Overflow poster was complaining that APPEND didn't create the file too.

[Campbell Ritchie]

Please search; I think somebody reported this problem a few weeks ago.

[Rob Spoor]

The official documentation of Files.newBufferedWriter is oddly unclear about what to do in this case.

Fortunately, I've written a few file system implementations myself, and therefore know that implementing a file system does not require implementing any methods for creating a writer. The only writable objects you can create are:
* an OutputStream: Files.newOutputStream
* a SeekableByteChannel: Files.newByteChannel

The documentation for newOutputStream clearly states that APPEND without CREATE should cause an exception to be thrown if the file does not exist. Therefore, answer C is correct, and the answer explanation is incorrect.