spring callstack¶

private static native Object invoke0(Method var0, Object var1, Object[] var2);

public Object invoke(Object var1, Object[] var2) throws IllegalArgumentException, InvocationTargetException {
        // step 0. 增加调用此方法的计数，此处应该是安全检查，与spring无关，不展开讨论,注意可能会抛出异常即可
        if(++this.numInvocations > ReflectionFactory.inflationThreshold() && !ReflectUtil.isVMAnonymousClass(this.method.getDeclaringClass())) {
            MethodAccessorImpl var3 = (MethodAccessorImpl)(new MethodAccessorGenerator()).generateMethod(this.method.getDeclaringClass(), this.method.getName(), this.method.getParameterTypes(), this.method.getReturnType(), this.method.getExceptionTypes(), this.method.getModifiers());
            this.parent.setDelegate(var3);
        }
        // step 1. 通过这行调用f1
        return invoke0(this.method, var1, var2);
    }

// 不是spring package的类，不展开讨论，注意一下函数签名即可
public Object invoke(Object var1, Object[] var2) throws IllegalArgumentException, InvocationTargetException {
        return this.delegate.invoke(var1, var2);
    }

// obj的内容是GreetingController, args里面只有一个“World”字符串
public Object invoke(Object obj, Object... args)
{
    ...
}

protected Method getBridgedMethod() {
        return this.bridgedMethod;
    }

// args里面只有一个“World”字符串
protected Object doInvoke(Object... args) throws Exception {
        // spring支持将greeting方法声明为private
        ReflectionUtils.makeAccessible(getBridgedMethod());
        try {
            // 此处调用f4
            return getBridgedMethod().invoke(getBean(), args);
        }
        catch (IllegalArgumentException ex) {
            ...
        }
        catch (InvocationTargetException ex) {
            ...
        }

// 入参的内容
// ServletWebRequest: uri=/greeting;client=127.0.0.1
// ModelAndViewContainer: View is [null]; default model {}
// 可以发现
public Object invokeForRequest(NativeWebRequest request, ModelAndViewContainer mavContainer,
            Object... providedArgs) throws Exception {

        // step 0. 从NativeWebRequest和ModelAndViewContainer 中提取参数，关注主要逻辑，暂不看细节实现
        Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs);

        // step 1. 打开trace log会有日志，protected final Log logger = LogFactory.getLog(getClass());
        if (logger.isTraceEnabled()) {
            StringBuilder sb = new StringBuilder("Invoking [");
            sb.append(getBeanType().getSimpleName()).append(".");
            sb.append(getMethod().getName()).append("] method with arguments ");
            sb.append(Arrays.asList(args));
            logger.trace(sb.toString());
        }

        // step 2. 此处调用f5
        Object returnValue = doInvoke(args);
        if (logger.isTraceEnabled()) {
            logger.trace("Method [" + getMethod().getName() + "] returned [" + returnValue + "]");
        }
        return returnValue;
    }

public void invokeAndHandle(ServletWebRequest webRequest,
            ModelAndViewContainer mavContainer, Object... providedArgs) throws Exception {

        // step 0. 此处调用f6来获取此次request的返回值
        Object returnValue = invokeForRequest(webRequest, mavContainer, providedArgs);
        // step 1. 设置webRequest对象的响应状态，在这次请求中，由于响应状态是null，实际上webRequest没有设置响应状态。
        // todo: 看一下greeting抛出exception时是怎样处理的。
        setResponseStatus(webRequest);

        // step 2. 处理mavContainer对象的状态
        ...
        mavContainer.setRequestHandled(true);

        // step 3. 处理返回值，值得一看，暂时略过，因为f8中会仔细分析
        this.returnValueHandlers.handleReturnValue(
                    returnValue, getReturnValueType(returnValue), mavContainer, webRequest);
        ...

    }

protected ModelAndView invokeHandlerMethod(HttpServletRequest request,
            HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
            // 可参考http://lgbolgger.iteye.com/blog/2111003
            ...
            // 此处调用f7
            invocableMethod.invokeAndHandle(webRequest, mavContainer);
            ...
    }

protected ModelAndView handleInternal(HttpServletRequest request,
            HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
            ...
}

public final ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {

        return handleInternal(request, response, (HandlerMethod) handler);
    }

protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {
        ...
        mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
        ...
}

protected void doService(HttpServletRequest request, HttpServletResponse response) throws Exception {
    ...
}

protected final void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            ...
}

protected final void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        processRequest(request, response);
    }

protected void service(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
        ...
}