Notes of Tomcat 系统架构与设计模式，第 1 部分 and Tomcat 系统架构与设计模式，第 2 部分.

🔗Tomcat Architecture

---------------------------------------------
| Server                                    |
| - Service                                 |
|   - Connector Coyote                      |
|   - Connector Coyote                      |
|   - Connector Coyote                      |
|   - Connector Coyote                      |
|   - ...                                   |
|   - Container Catalina                    |
|   - Session                               |
|   - Jasper                                |
|   - Naming                                |
|   - Logging                               |
|   - JMX                                   |
---------------------------------------------

🔗Structures

🔗LifeCycle

void addLifecycleListner(...)
void removeLifecycleListener(...)
LifecycleListeners findLifecycleListeners()
void start()
void stop()

🔗Server

A "Server" is a manager of a collection of "Service".

🔗Service

A "Service" is a combination of a "Container" and multi "Connector" together with several utils.

🔗Connector

A "Connector" receive http request and post http response.

When a http connection comes, a "Connector" passed it to a "Processor" via Processor::assign().

🔗Processor

A "Processor" constructs a http request and response and passed it to a "Container".

🔗Container

A "Container" is a role, including "Wrapper", "Context", "Host" and "Engine".

Engine
    |- Host 0
        |- Context
            |- Wrapper
    |- Host 1
        |- Context
            |- Wrapper

🔗Engine

An "Engine" has no parent.

Engine interface
    - String get DefaultHost()
    - void setDefaultHost(String)
    - String getJvmRoute()
    - void setJvmRoute(String)
    - Service getService()
    - void setService(Service)
    - void addDefaultContext(DefaultContext)
    - DefaultContext getDefaultContext()
    - void importDefaultContext()

StandardEngine implements Engine.

• Cluster: load balance
• Realm: security management
• Pipeline: logic
• Valve: operations

🔗Host

A "Host" is a deployer.

• Cluster: load balance
• Realm: security management
• Pipeline: logic
• Valve: operations

🔗Context

A "Context" is the place where to run a servlet.

• Cluster: load balance
• Realm: security management
• Pipeline: logic
• Valve: operations
• Manager: session management org.apache.catalina.session.StandardManager
• Resources
• Loader: class loader
• Mapper: URL map to wrapper

🔗Wrapper

A "Wrapper" is a servlet.

• Pipeline: logic
• Valve: operations
• Servlet
• Servelet stack

Following classes implementing "Wrapper".

• org.apache.catalina.servlets.DefaultServlet
• org.apache.jasper.servlet.JspServlet

🔗Pipeline and Valve

• org.apache.catalina.core.ContainerBase
• org.apache.catalina.core.StandardEngine
• org.apache.catalina.core.StandardHost
• org.apache.catalina.core.StandardContext
• org.apache.catalina.core.StandardWrapper
• org.apache.catalina.core.StandardPipeline
• org.apache.catalina.valves.ValveBase
• org.apache.catalina.core.StandardEngineValve
• org.apache.catalina.core.StandardHostValve
• org.apache.catalina.core.StandardContextValve
• org.apache.catalina.core.StandardWrapperValve