What would you enable to allow a browser to another site to make an Ajax request to API

To allow a browser on another site to make an Ajax request to an API, you would need to enable Cross-Origin Resource Sharing (CORS) on the server that provides the API.

CORS is a mechanism that allows a web page to make a request to a different domain than the one the page came from. By default, web browsers restrict such requests to prevent security vulnerabilities. However, if the server that provides the API enables CORS, it can specify which domains are allowed to make requests, and the browser will allow requests from those domains.

To enable CORS on the server that provides the API, you would need to add specific HTTP headers to the response that the server sends back to the browser. The headers that need to be added are:

• Access-Control-Allow-Origin: This header specifies the domains that are allowed to make requests. You can set this header to "*" to allow requests from any domain, or you can set it to a specific domain.
• Access-Control-Allow-Methods: This header specifies the HTTP methods that are allowed for the request. For example, if you only want to allow GET requests, you would set this header to "GET".
• Access-Control-Allow-Headers: This header specifies the HTTP headers that are allowed for the request. For example, if you want to allow requests that contain an "Authorization" header, you would set this header to "Authorization".

Here is an example of how to enable CORS in a Java Servlet API:

import javax.servlet.ServletException;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.IOException;

public class MyServlet extends HttpServlet {

    @Override

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        response.addHeader("Access-Control-Allow-Origin", "*");

        response.addHeader("Access-Control-Allow-Methods", "GET");

        response.addHeader("Access-Control-Allow-Headers", "Authorization");

        // ...

    }

}

In this example, the `doGet()` method of the `MyServlet` class adds the CORS headers to the response object. The `Access-Control-Allow-Origin` header is set to "*", which allows requests from any domain. The `Access-Control-Allow-Methods` header is set to "GET", which allows only GET requests. The `Access-Control-Allow-Headers` header is set to "Authorization", which allows requests that contain an "Authorization" header.

Note that the specific headers that need to be set may vary depending on the requirements of the API you are using.