Static web page http request problem

Yes, just did a test, static html page, using jQuery to initiate an ajax request, request the background project running under the local Tomcat to get json data.

1. Visit directly through the web page:

option
2.webstorm:

got the data
I would like to ask whether the static web page can issue a http request to get the json data from the background? If not, why not? If I can, why do I only issue option requests when I do the test? Does issuing an option request without subsequent action mean that the http request failed? I have looked up a lot of information on the Internet, but there is a big difference. I beg your pardon.

Javascript
Feb.28,2021

static pages when people allow you to ajax, this is obviously js cross-domain, because of security issues, tomcat does not allow cross-domain by default. Option request is to see whether the server supports cross-domain. If cross-domain is not allowed, the browser will not send ajax request to the backend server. If you want to allow cross-domain, the server should add a http header: Access-Control-Allow-Origin

1. Static web page using ajax is able to issue http requests, get json data
2. You only send an options request because it is cross-domain. The browser will first send an options pre-request to see if the backend supports cross-domain access. The back-end interface needs to handle the options request. Learn about cors

across domains.

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MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e467bb-651d3.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e467bb-651d3.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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