Why is it safer to transmit data via POST rather than GET?

Data transmission via POST is considered safer than via GET for several reasons:

1. Data is not displayed in the URL. In GET, parameters are passed in the URL query string, making them visible in the browser's address bar, server logs, browser history, and proxy servers. POST transmits data in the request body, hiding it from these places.

2. Length limitation. URLs have a length limit, which can lead to data truncation in GET, whereas POST allows transmitting larger amounts of data.

3. Protection against accidental repeated requests. GET requests can be easily repeated (for example, when refreshing the page), which may lead to unwanted actions, while POST requires explicit confirmation.

However, it is important to understand that POST does not encrypt data — to protect against interception, HTTPS should be used.

Example of sending data via POST in Java using HttpURLConnection:

URL url = new URL("https://example.com/api");
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.setRequestMethod("POST");
con.setDoOutput(true);
String postData = "username=user&password=pass";
try(OutputStream os = con.getOutputStream()) {
    byte[] input = postData.getBytes("utf-8");
    os.write(input, 0, input.length);
}
int responseCode = con.getResponseCode();