The search engine is configured in the project, and the solr framework is integrated into tomcat. Now review the principle of the search engine.
The article to read is this link: http://www.importnew.com/12707.html
One of the things I didn't understand at first:
Reverse index: The general idea is that, to find a keyword A, it will search the documents one by one, that is, the idea of finding keywords from the document.
What solr uses is to first establish the index order of keywords to documents, so it can be called reverse indexing.