favorites ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓ https://developer.mozilla.org/zh-CN/docs/learn ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
webpage check ↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓ https://validator.w3.org/#validate_by_uri ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
develop tools https://developer.mozilla.org/en-US/docs/Learn/JavaScript/Client-side_web_APIs/Third_party_APIs
struts: http://amateras.osdn.jp/cgi-bin/fswiki_en/wiki.cgi?page=StrutsIDE
spring Demo https://gitee.com/oschina/spring-demo
demo http://www.demodashi.com/demo/12947.html
vjpage http://www.vjong.com/html/class1_1.html