When using Eclipse to export java doc, it prompts "unmappable character encoding GBK", which should be the Chinese comment Eclipse does not recognize. You need to pass the encoding set when calling javadoc.exe to tell it what encoding to use to generate the javadoc document.
Open eclipse, project -> Export -> javadoc, select the project you want to output javadoc one by one, and add the following code to the VM setting line in the last step
-encoding utf-8 -charset utf-8
After the above operations, the "unmappable character encoding GBK" problem will not occur in the output html code, and the html character encoding is set to UTF-8, the problem is completely solved.