How do I perform/work the call through the AJAX url?

Question

To put it in context:

There is a remote directory, clearing-dit\logs, which has a number of logs (portal.log, test.log, ...). This directory, is mapped to an HTML page, where all of its .log's are displayed. Once one of them is clicked, its respective content is displayed.

This content is loaded through the HTML/Thymeleaf page, which calls the content a log.java.

<p th:utext="${log.content}">Log content</p>

The need arose to make this content continue to be displayed (its updates) every 5 seconds, in real time and without having to update the entire page, only updating where the content is. I have been researching and I saw that I can/should do it through an AJAX, but his concept is somewhat vague for me.

My doubt:

How do I perform/work the call through the AJAX url? I know that in AJAX there are two type fields -> POST/GET and the url -> (?), but I cannot understand how this "crossover" works, because, in theory, if it were possible to call the method that displays the current content:

@RequestMapping(value = "/log", method = RequestMethod.POST)
    public String logContent(@Valid Log log, BindingResult bindingResult, Map<String, Object> model) {
        if (log.getInitLine() == 0 && log.getFinalLine() == 0) {
            try {
                fileNumberLines(log);
                log.setContent(getLogContentByRange(0, log.getInitLine(), log.getFinalLine(), logsDir + "/" + log.getFilename()));
            } catch (IOException e) {
                logger.error(e.getMessage());
            }
        } else {
            log.setContent(getLogContentByRange(0, log.getInitLine(), log.getFinalLine(), logsDir + "/" + log.getFilename()));
        }

        model.put("path", logsDir);
        model.put("log", log);
        model.put("currentPage", "logs");
        model.put("root", root);

        return "log";
    }

Every five seconds, it would solve the problem.