用了好长时间tomcat，但是其实自己只是反复听了这个名字，对Tomcat并不了解
1、Tomcat组件
- Catalina
- Coyote
- Jasper
- Cluster
2、组件介绍
Tomcat Component are
- Catalina
- Coyote
- Jasper
- Cluster
Catalina : Catalina is the name of the servlet container of Apache Tomcat since version 4.x. Tomcat implements Sun Microsystems' specifications for servlet and JavaServer Pages (JSP), which are important Java-based Web technologies. Tomcat's servlet container was redesigned as Catalina in Tomcat version 4.x. other components of the Tomcat engine are:
Tomcat Jasper which converts the code portions within JavaServer Pages into servlets and pass them to Catalina to process.
Tomcat Coyote which is an HTTP connector based on HTTP/1.1 specifications that receives and transmits web requests to the Tomcat engine by listening to a TCP/IP port and returns requests back to the requesting client.
Coyote : The Coyote JK Connector element represents a Connector component that communicates with a web connector via the JK protocol (also known as the AJP protocol). This is used for cases where you wish to invisibly integrate Tomcat 4 into an existing (or new) web server installation, and you want the web server to handle the static content contained in the web application, and/or utilize the web server's SSL processing. In many application environments, this will result in better overall performance than running your applications under Tomcat stand-alone using the Coyote HTTP/1.1 Connector. However, the only way to know for sure whether it will provide better performance for your application is to try it both ways.
Jasper : Jasper is Tomcat's JSP Engine. Jasper parses JSP files to compile them into Java code as servlets (that can be handled by Catalina). At runtime, Jasper detects changes to JSP files and recompiles them.
Cluster : This component has been added to manage large applications. It is used for load balancing that can be achieved through many techniques. Clustering support currently requires the JDK version 1.5 or later