实习期间,公司使用jfinal做开发,所以就学习了这个框架
Jfinal作为一个极速ORM,使用上非常方便,核心源代码1万多行,压缩后只有200多KB。
从入口开始
作为一个web项目,首先解读web.xml文件,其中配置了一个filter,
<filter-class>com.jfinal.core.JFinalFilter</filter-class>
finalfilter继承了filter。
关于filkter:filter是jsp中的一个接口,需要实现的方法有Init(),doFilter(),和destroy()三个必要的方法。
打开源代码中的JfinalFilter往下解读进入public void init(FilterConfig filterConfig) ,createJFinalConfig函数作用是初始化jfinalConfig,它使用了java反射方式查找,使用class.newInstance()方法实例化一个对象,再将temp对象强制转化成JFinalConfig对象
初始化完成jfinalConfig之后,使用了jfinal.init(jfinalConfig, filterConfig.getServletContext())这一方法。
再次进入JFinal类
public final class JFinal{
.............
boolean init(JFinalConfig jfinalConfig, ServletContext servletContext) {
this.servletContext = servletContext;
this.contextPath = servletContext.getContextPath();
initPathUtil();//获得webroot路径
Config.configJFinal(jfinalConfig); // start plugin and init logger factory in this method
constants = Config.getConstants();
initActionMapping();
initHandler();
initRender();
initActiveRecord();
initOreillyCos();
initI18n();
initTokenManager();
return true;
}
}
Config.configJFinal(jfinalConfig);方法为Config类中的几个静态变量赋值,并启动插件
initActionMapping();initHandler();initRender();initActiveRecord();initOreillyCos();initI18n();initTokenManager();依次做了初始化工作。
private void initActionMapping() {
actionMapping = new ActionMapping(Config.getRoutes(), Config.getInterceptors()); //传入了jfinalconfig中的routs和Interceptors,jfinalConfig中的Interceptors为全局拦截器
actionMapping.buildActionMapping();
}
initActionMapping是jfinal中核心设计,代码比较长
private final Map<String, Action> mapping = new HashMap<String, Action>(); void buildActionMapping() {
mapping.clear();
Set<String> excludedMethodName = buildExcludedMethodName(); //获得Controller自带的一些方法名称
InterceptorBuilder interceptorBuilder = new InterceptorBuilder();
Interceptor[] defaultInters = interceptors.getInterceptorArray();
interceptorBuilder.addToInterceptorsMap(defaultInters);
for (Entry<String, Class<? extends Controller>> entry : routes.getEntrySet()) {//循环遍历routs
Class<? extends Controller> controllerClass = entry.getValue();
Interceptor[] controllerInters = interceptorBuilder.buildControllerInterceptors(controllerClass); //在buildControllerInterceptors方法中,如果有Before声明
Method[] methods = controllerClass.getMethods(); //获取controllerClass所有方法
for (Method method : methods) {
String methodName = method.getName();
if (!excludedMethodName.contains(methodName) && method.getParameterTypes().length == 0) { //无参数函数为action,且不是基类Controller.class包含的方法
Interceptor[] methodInters = interceptorBuilder.buildMethodInterceptors(method);//在此方法中 查找Before
Interceptor[] actionInters = interceptorBuilder.buildActionInterceptors(defaultInters, controllerInters, controllerClass, methodInters, method);//返回整个action的拦截器[Interceptor]
String controllerKey = entry.getKey(); //controllerKey即为path路径 ActionKey ak = method.getAnnotation(ActionKey.class);//获得注解actionkey
if (ak != null) {
String actionKey = ak.value().trim();
if ("".equals(actionKey))
throw new IllegalArgumentException(controllerClass.getName() + "." + methodName + "(): The argument of ActionKey can not be blank."); if (!actionKey.startsWith(SLASH))
actionKey = SLASH + actionKey; if (mapping.containsKey(actionKey)) {
warnning(actionKey, controllerClass, method);
continue;
} Action action = new Action(controllerKey, actionKey, controllerClass, method, methodName, actionInters, routes.getViewPath(controllerKey));
mapping.put(actionKey, action);
}
else if (methodName.equals("index")) {//index为默认的
String actionKey = controllerKey; Action action = new Action(controllerKey, actionKey, controllerClass, method, methodName, actionInters, routes.getViewPath(controllerKey));
action = mapping.put(actionKey, action); if (action != null) {
warnning(action.getActionKey(), action.getControllerClass(), action.getMethod());
}
}
else {
String actionKey = controllerKey.equals(SLASH) ? SLASH + methodName : controllerKey + SLASH + methodName; if (mapping.containsKey(actionKey)) {
warnning(actionKey, controllerClass, method);
continue;
} Action action = new Action(controllerKey, actionKey, controllerClass, method, methodName, actionInters, routes.getViewPath(controllerKey));
mapping.put(actionKey, action);
}
}
}
} // support url = controllerKey + urlParas with "/" of controllerKey
Action actoin = mapping.get("/");
if (actoin != null)
mapping.put("", actoin);
}
buildExcludedMethodName()首先将Controllerlei中的无参函数取出,放入set集合中
private Set<String> buildExcludedMethodName() {
Set<String> excludedMethodName = new HashSet<String>();
Method[] methods = Controller.class.getMethods();
for (Method m : methods) {
if (m.getParameterTypes().length == 0)
excludedMethodName.add(m.getName());
}
return excludedMethodName;
}
Interceptor[] defaultInters = interceptors.getInterceptorArray();获得全局拦截器,转换成数组后的GlobalInterceptor
然后for循环遍历routs
循环中
Interceptor[] controllerInters = interceptorBuilder.buildControllerInterceptors(controllerClass); 返回controller中的Before声明
Interceptor[] buildControllerInterceptors(Class<? extends Controller> controllerClass) {
Before before = controllerClass.getAnnotation(Before.class);
return before != null ? createInterceptors(before) : NULL_INTERCEPTOR_ARRAY;
}
在循环routs中嵌套循环遍历每一个函数方法
这里就知道了为什么Controller中的无参函数才是一个action
if (!excludedMethodName.contains(methodName) && method.getParameterTypes().length == 0) {
//controller中的无参,并且不是基类Controller的方法
..............................
}
返回的每一个controller中无参的方法即为一个action
Interceptor[] methodInters = interceptorBuilder.buildMethodInterceptors(method);
Interceptor[] actionInters = interceptorBuilder.buildActionInterceptors(defaultInters, controllerInters, controllerClass, methodInters, method);
构建action的所有拦截器,interceptorBuilder.buildActionInterceptors(defaultInters, controllerInters, controllerClass, methodInters, method);中勿个参数就分别对应了全局拦截器,controller拦截器,controller类,action声明的before拦截器和方法体。
action的生成遵循几个规则:
1、如果声明了actionkey注解,就根据actionkey中的声明。
2、若方法名是index(),则action就于controllerkey。
3、否则actionkey等于 controllerkey+“/”+methodName