Eclipse New servlet error, packet-less solution

When I created the servlet, there were a lot of errors, and the visual was not introducing various packages

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The workaround is to open the Properties->java Bulid path->libraries->add libraries->server Runtime, select the Tomcat server, If the server runtime is empty because there are no servers added, add the runtime Environment: Window->preferences->server->runtime Enviroment->add, Select the Tomcat version to make sure that the red line markers in the project are gone.

Eclipse New servlet error, packet-less solution