stripes 的Intercept Execution

protected Map<LifecycleStage, Collection<Interceptor>> initInterceptors() {
        String classList = getBootstrapPropertyResolver().getProperty(INTERCEPTOR_LIST);
        if (classList == null) {
            return null;
        }
        else {
            String[] classNames = StringUtil.standardSplit(classList);
            Map<LifecycleStage, Collection<Interceptor>> map =
                    new HashMap<LifecycleStage, Collection<Interceptor>>();

            for (String className : classNames) {
                try {
                    Class<? extends Interceptor> type = ReflectUtil.findClass(className.trim());
                    Intercepts intercepts = type.getAnnotation(Intercepts.class);
                    if (intercepts == null) {
                        log.error("An interceptor of type ", type.getName(), " was configured ",
                                  "but was not marked with an @Intercepts annotation. As a ",
                                  "result it is not possible to determine at which ",
                                  "lifecycle stages the interceprot should be applied. This ",
                                  "interceptor will be ignored.");
                    }
                    else {
                        log.debug("Configuring interceptor '", type.getSimpleName(),
                                  "', for lifecycle stages: ", intercepts.value());
                    }

                    // Instantiate it and optionally call init() if the interceptor
                    // implements ConfigurableComponent
                    Interceptor interceptor = type.newInstance();
                    if (interceptor instanceof ConfigurableComponent) {
                        ((ConfigurableComponent) interceptor).init(this);
                    }

                    for (LifecycleStage stage : intercepts.value()) {
                        Collection<Interceptor> stack = map.get(stage);
                        if (stack == null) {
                            stack = new LinkedList<Interceptor>();
                            map.put(stage, stack);
                        }

                        stack.add(interceptor);
                    }
                }
                catch (Exception e) {
                    throw new StripesRuntimeException(
                            "Could not instantiate one or more configured Interceptors. The " +
                            "property '" + INTERCEPTOR_LIST + "' contained [" + classList +
                            "]. This value must contain fully qualified class names separated " +
                            "by commas.", e);
                }
            }

            return map;
        }
}

这个方法取到配置中的拦截器s,并实例化它们，之后按生命周期分成6类放在renturn中的Map<LifecycleStage, Collection<Interceptor>>中。现在回到resolveHandler方法，这个方法接下来就是return ctx.wrap( new Interceptor() {..});这个实现了一个匿名的Interceptor，之后执行ExcuteContext.wrap(Interceptor)方法。还记得wrap（interceptor）,它是一个包扎方法，把这个匿名Interceptor保存ExcuteContext   的target对象。this.target = target;接下的这句 this.iterator = null;仅仅是代码的实现技巧，这个是要在下面的 return proceed();做判断处理。

public Resolution proceed() throws Exception {
        if (this.iterator == null) {
         log.debug("Transitioning to lifecycle stage ", lifecycleStage);
            this.iterator = this.interceptors.iterator();        }
        if (this.iterator.hasNext()) {
            return this.iterator.next().intercept(this);        }
        else {      return this.target.intercept(this);       }    }