1.读源码当然从入口开始读 web.xml,非常简单一个filter

    
     
      jfinal
     
     
      com.jfinal.core.JFinalFilter
     
     
      
       configClass
      
      
       com.demo.common.DemoConfig
      
     
    
    
     
      jfinal
     
     
      /*
     
    

public void init(FilterConfig filterConfig) throws ServletException {		createJFinalConfig(filterConfig.getInitParameter("configClass"));				if (jfinal.init(jfinalConfig, filterConfig.getServletContext()) == false)			throw new RuntimeException("JFinal init error!");				handler = jfinal.getHandler();		constants = Config.getConstants();		encoding = constants.getEncoding();		jfinalConfig.afterJFinalStart();				String contextPath = filterConfig.getServletContext().getContextPath();		contextPathLength = (contextPath == null || "/".equals(contextPath) ? 0 : contextPath.length());	}

   3.createJFinalConfig,就是实例化上面的param-value中的值

private void createJFinalConfig(String configClass) {		if (configClass == null)			throw new RuntimeException("Please set configClass parameter of JFinalFilter in web.xml");				try {			Object temp = Class.forName(configClass).newInstance();			if (temp instanceof JFinalConfig)				jfinalConfig = (JFinalConfig)temp;			else				throw new RuntimeException("Can not create instance of class: " + configClass + ". Please check the config in web.xml");		} catch (InstantiationException e) {			throw new RuntimeException("Can not create instance of class: " + configClass, e);		} catch (IllegalAccessException e) {			throw new RuntimeException("Can not create instance of class: " + configClass, e);		} catch (ClassNotFoundException e) {			throw new RuntimeException("Class not found: " + configClass + ". Please config it in web.xml", e);		}	}

  4.jfinal.init才是代码初始化的关键

boolean init(JFinalConfig jfinalConfig, ServletContext servletContext) {		this.servletContext = servletContext;		this.contextPath = servletContext.getContextPath();				initPathUtil();				Config.configJFinal(jfinalConfig);	// start plugin and init logger factory in this method		constants = Config.getConstants();				initActionMapping();		initHandler();		initRender();		initActiveRecord();		initOreillyCos();		initI18n();		initTokenManager();				return true;	}

private void initPathUtil() {		String path = servletContext.getRealPath("/");		PathKit.setWebRootPath(path);	}

public static void setWebRootPath(String webRootPath) {		if (webRootPath == null)			return ;				if (webRootPath.endsWith(File.separator))			webRootPath = webRootPath.substring(0, webRootPath.length() - 1);		PathKit.webRootPath = webRootPath;	}

6.Config.configJFinal(jfinalConfig);

jfinalConfig.configConstant(constants);				initLoggerFactory();		jfinalConfig.configRoute(routes);		jfinalConfig.configPlugin(plugins);					startPlugins();	// very important!!!		jfinalConfig.configInterceptor(interceptors);		jfinalConfig.configHandler(handlers);

private static void initLoggerFactory() {		Logger.init();		log = Logger.getLogger(Config.class);		JFinalFilter.initLogger();	}