Happycat

a web server from learning tomcat server

💡 Introduction

this project is tiny as no more than 5000 lines but covers many features of a web server and totally writen by Java, is suitable for newbies to learn Java and web server knoweldge

✨ Composition

1. happyBrowser : send and review http message with code

2. unit test : stablely interate project and show use case of this project

3. happycat log : rotate log happycat server running info

4. parallel process requests

5. muti-port and muti-webapp

   1. Server、Service、Connector、Engine、Host、Context implementation
   2. parse context.xml、server.xml、web.xml

6. http specification

   1. 200 : normal response
   2. 404 : client error
   3. 500 : server error
   4. compression
   5. client jump
   6. server jump
   7. cookie
   8. session

7. servlet

   1. InvokeServlet : handle requests definied in webapp's web.xml
   2. DefalutServlet : handle static resource requests
   3. JspServlet : handle JSP request
   4. servlet life time
   5. servlet automatic start

8. class load mechanism

   1. CommonClassLoader : load happycat build-in classes
   2. WebClassLoader : load webapp classes
   3. JspClassLoader : load JSP classes

9. webapp deployment

   10. webapp hot loadding
   11. war file dynamic deployment

10. webapp filter

11. webapp listener

🔍Class-diagram for core classes

🔍 Sequence-diagram for a 200 request

💻 How to deploy

1. build jar with idea
2. copy b/、cong/、javaweb/、lib/、log/、webapps/、work/ to the directory of jar file
3. config right docbase of happycat/conf/server.xml
4. run with "java -jar happycat.jar"

👀 Reference

• http://tomcat.apache.org/
• Apache Tomcat Cookbook
• Tomcat架构解析
• How Tomcat Works
• Tomcat the definitive guide
• Specification UML 2.5.1
• UMLDistilled
• PlantUML_Language_Reference_Guide_en
• UML_for_Java_Programmers-Book
• core Java

🙏 Acknowledgement

• jsoup: Java HTML parser
• hutool：A set of tools that keep Java sweet
• tomcat：A widely used web server