Tomcat启动,类的加载顺序(参考Apache Tomcat 6.0 Class Loader)

      Bootstrap
          |
       System
          |
       Common
       /     \
  Webapp1   Webapp2 ...
 
 
Bootstrap :
包含了$JAVA_HOME/jre/lib和$JAVA_HOME/jre/lib/ext的类库,提供JVM支持


System :
$CATALINA_HOME/bin/bootstrap.jar - 包含main()函数
$CATALINA_HOME/bin/tomcat-juli.jar - Jakarta commons logging API, and java.util.logging LogManager


Common :
目录$CATALINA_HOME/lib下的类库:
默认有:
* annotations-api.jar - JEE annotations classes.
* catalina.jar - Implementation of the Catalina servlet container portion of Tomcat 6.
* catalina-ant.jar - Tomcat Catalina Ant tasks.
* catalina-ha.jar - High availability package.
* catalina-tribes.jar - Group communication package.
* el-api.jar - EL 2.1 API.
* jasper.jar - Jasper 2 Compiler and Runtime.
* jasper-el.jar - Jasper 2 EL implementation.
* jasper-jdt.jar - Eclipse JDT 3.2 Java compiler.
* jsp-api.jar - JSP 2.1 API.
* servlet-api.jar - Servlet 2.5 API.
* tomcat-coyote.jar - Tomcat connectors and utility classes.
* tomcat-dbcp.jar - package renamed database connection pool based on Commons DBCP.
* tomcat-i18n-**.jar - Optional JARs containing resource bundles for other languages. As default bundles are also included in each individual JAR, they can be safely removed if no internationalization of messages is needed.