Initialization parameters for a servlet are configured in the web.xml file.

HttpOnly cookies cannot be accessed by JavaScript, making them more secure against XSS attacks as malicious scripts won't have access to sensitive cookie information.

Stored XSS involves the injection of malicious scripts that persist on the target, whereas Reflected XSS involves non-persistent injection and reflects the payload back to the user.

Advanced XSS attacks may bypass input sanitization through techniques like exploiting browser vulnerabilities, making sanitization ineffective in preventing such attacks.

Subresource Integrity (SRI) is a security feature that helps prevent XSS attacks by ensuring the integrity of external scripts, validating and verifying that they haven't been tampered with.

To prevent XSS attacks, it is essential to sanitize user input and encode user output. Sanitizing helps remove potentially harmful content, and encoding ensures that user data is displayed correctly and safely in the browser.

Content Security Policy (CSP) is a security standard that prevents the browser from interpreting user input as a script. It helps mitigate the risk of XSS attacks by defining and enforcing a set of rules for how resources should be loaded on a web page.

When implementing CSP, the connect-src directive is crucial in restricting resources the page can load. It controls which URLs the document is allowed to make requests to, helping prevent unwanted network requests that could pose security risks.

In a stored XSS attack, the injected script is stored on the server and served to users, making it more dangerous.

HTML encoding is a common technique to prevent XSS by converting special characters into HTML entities, making it difficult for attackers to inject malicious scripts.