在之前的博客中我们已经接触过HandlerMethod,接下来我们简单介绍一下HandlerMethod,简单来说HandlerMethod包含的信息包括类、方法和参数的一个信息类,通过其两个构造函数我们就可以了解其功能,对应着springMVC的Controller来说就是某个url对应的某个Controller执行的方法。

/**
	 * Create an instance from a bean instance and a method.
	 */
	public HandlerMethod(Object bean, Method method) {
		Assert.notNull(bean, "Bean is required");
		Assert.notNull(method, "Method is required");
		this.bean = bean;
		this.beanFactory = null;
		this.beanType = ClassUtils.getUserClass(bean);
		this.method = method;
		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
		this.parameters = initMethodParameters();
		this.resolvedFromHandlerMethod = null;
	}
/**
	 * Create an instance from a bean instance, method name, and parameter types.
	 * @throws NoSuchMethodException when the method cannot be found
	 */
	public HandlerMethod(Object bean, String methodName, Class<?>... parameterTypes) throws NoSuchMethodException {
		Assert.notNull(bean, "Bean is required");
		Assert.notNull(methodName, "Method name is required");
		this.bean = bean;
		this.beanFactory = null;
		this.beanType = ClassUtils.getUserClass(bean);
		this.method = bean.getClass().getMethod(methodName, parameterTypes);
		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(this.method);
		this.parameters = initMethodParameters();
		this.resolvedFromHandlerMethod = null;
	}

完整源码如下:

public class HandlerMethod {

	/** Logger that is available to subclasses */
	protected final Log logger = LogFactory.getLog(getClass());

	private final Object bean;

	private final BeanFactory beanFactory;

	private final Class<?> beanType;

	private final Method method;

	private final Method bridgedMethod;

	private final MethodParameter[] parameters;

	private final HandlerMethod resolvedFromHandlerMethod;

	//创建一个实例,根据bean实例和method方法
	public HandlerMethod(Object bean, Method method) {
		Assert.notNull(bean, "Bean is required");
		Assert.notNull(method, "Method is required");
		this.bean = bean;
		this.beanFactory = null;
		this.beanType = ClassUtils.getUserClass(bean);
		this.method = method;
		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
		this.parameters = initMethodParameters();
		this.resolvedFromHandlerMethod = null;
	}
	//根据bean,方法名以及参数类型创建实例
	public HandlerMethod(Object bean, String methodName, Class<?>... parameterTypes) throws NoSuchMethodException {
		Assert.notNull(bean, "Bean is required");
		Assert.notNull(methodName, "Method name is required");
		this.bean = bean;
		this.beanFactory = null;
		this.beanType = ClassUtils.getUserClass(bean);
		this.method = bean.getClass().getMethod(methodName, parameterTypes);
		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(this.method);
		this.parameters = initMethodParameters();
		this.resolvedFromHandlerMethod = null;
	}
	//根据bean名称,BeanFactory工厂和method方法创建实例
	public HandlerMethod(String beanName, BeanFactory beanFactory, Method method) {
		Assert.hasText(beanName, "Bean name is required");
		Assert.notNull(beanFactory, "BeanFactory is required");
		Assert.notNull(method, "Method is required");
		this.bean = beanName;
		this.beanFactory = beanFactory;
		this.beanType = ClassUtils.getUserClass(beanFactory.getType(beanName));
		this.method = method;
		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
		this.parameters = initMethodParameters();
		this.resolvedFromHandlerMethod = null;
	}

	protected HandlerMethod(HandlerMethod handlerMethod) {
		Assert.notNull(handlerMethod, "HandlerMethod is required");
		this.bean = handlerMethod.bean;
		this.beanFactory = handlerMethod.beanFactory;
		this.beanType = handlerMethod.beanType;
		this.method = handlerMethod.method;
		this.bridgedMethod = handlerMethod.bridgedMethod;
		this.parameters = handlerMethod.parameters;
		this.resolvedFromHandlerMethod = handlerMethod.resolvedFromHandlerMethod;
	}
	private HandlerMethod(HandlerMethod handlerMethod, Object handler) {
		Assert.notNull(handlerMethod, "HandlerMethod is required");
		Assert.notNull(handler, "Handler object is required");
		this.bean = handler;
		this.beanFactory = handlerMethod.beanFactory;
		this.beanType = handlerMethod.beanType;
		this.method = handlerMethod.method;
		this.bridgedMethod = handlerMethod.bridgedMethod;
		this.parameters = handlerMethod.parameters;
		this.resolvedFromHandlerMethod = handlerMethod;
	}

	private MethodParameter[] initMethodParameters() {
		int count = this.bridgedMethod.getParameterTypes().length;
		MethodParameter[] result = new MethodParameter[count];
		for (int i = 0; i < count; i++) {
			result[i] = new HandlerMethodParameter(i);
		}
		return result;
	}

	public Object getBean() {
		return this.bean;
	}

	public Method getMethod() {
		return this.method;
	}

	public Class<?> getBeanType() {
		return this.beanType;
	}

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

	public MethodParameter[] getMethodParameters() {
		return this.parameters;
	}

	public HandlerMethod getResolvedFromHandlerMethod() {
		return this.resolvedFromHandlerMethod;
	}

	public MethodParameter getReturnType() {
		return new HandlerMethodParameter(-1);
	}

	public MethodParameter getReturnValueType(Object returnValue) {
		return new ReturnValueMethodParameter(returnValue);
	}

	public boolean isVoid() {
		return Void.TYPE.equals(getReturnType().getParameterType());
	}

	//获取方法上的注解,单个注解,如果没有注解则返回方法本身
	public <A extends Annotation> A getMethodAnnotation(Class<A> annotationType) {
		return AnnotatedElementUtils.findMergedAnnotation(this.method, annotationType);
	}

	//创建handlerMethod
	public HandlerMethod createWithResolvedBean() {
		Object handler = this.bean;
		if (this.bean instanceof String) {
			String beanName = (String) this.bean;
			handler = this.beanFactory.getBean(beanName);
		}
		return new HandlerMethod(this, handler);
	}
	@Override
	public boolean equals(Object other) {
		if (this == other) {
			return true;
		}
		if (!(other instanceof HandlerMethod)) {
			return false;
		}
		HandlerMethod otherMethod = (HandlerMethod) other;
		return (this.bean.equals(otherMethod.bean) && this.method.equals(otherMethod.method));
	}

	@Override
	public int hashCode() {
		return (this.bean.hashCode() * 31 + this.method.hashCode());
	}

	@Override
	public String toString() {
		return this.method.toGenericString();
	}

	/**
	 * A MethodParameter with HandlerMethod-specific behavior.
	 */
	protected class HandlerMethodParameter extends SynthesizingMethodParameter {

		public HandlerMethodParameter(int index) {
			super(HandlerMethod.this.bridgedMethod, index);
		}

		@Override
		public Class<?> getContainingClass() {
			return HandlerMethod.this.getBeanType();
		}

		@Override
		public <T extends Annotation> T getMethodAnnotation(Class<T> annotationType) {
			return HandlerMethod.this.getMethodAnnotation(annotationType);
		}
	}

	/**
	 * A MethodParameter for a HandlerMethod return type based on an actual return value.
	 */
	private class ReturnValueMethodParameter extends HandlerMethodParameter {

		private final Object returnValue;

		public ReturnValueMethodParameter(Object returnValue) {
			super(-1);
			this.returnValue = returnValue;
		}

		@Override
		public Class<?> getParameterType() {
			return (this.returnValue != null ? this.returnValue.getClass() : super.getParameterType());
		}
	}

}

springMVC源码分析--HandlerMethod的更多相关文章

  1. springMVC源码分析--访问请求执行ServletInvocableHandlerMethod和InvocableHandlerMethod

    在之前一篇博客中springMVC源码分析--RequestMappingHandlerAdapter(五)我们已经简单的介绍到具体请求访问的执行某个Controller中的方法是在RequestMa ...

  2. springMVC源码分析--AbstractHandlerMethodMapping注册url和HandlerMethod对应关系(十一)

    在上一篇博客springMVC源码分析--AbstractHandlerMethodMapping获取url和HandlerMethod对应关系(十)中我们简单地介绍了获取url和HandlerMet ...

  3. springMVC源码分析--AbstractHandlerMethodMapping获取url和HandlerMethod对应关系(十)

    在之前的博客springMVC源码分析--AbstractHandlerMapping(二)中我们介绍了AbstractHandlerMethodMapping的父类AbstractHandlerMa ...

  4. 8、SpringMVC源码分析(3):分析ModelAndView的形成过程

    首先,我们还是从DispatcherServlet.doDispatch(HttpServletRequest request, HttpServletResponse response) throw ...

  5. 7、SpringMVC源码分析(2):分析HandlerAdapter.handle方法,了解handler方法的调用细节以及@ModelAttribute注解

    从上一篇 SpringMVC源码分析(1) 中我们了解到在DispatcherServlet.doDispatch方法中会通过 mv = ha.handle(processedRequest, res ...

  6. springMVC源码分析--RequestMappingHandlerAdapter(五)

    上一篇博客springMVC源码分析--HandlerAdapter(一)中我们主要介绍了一下HandlerAdapter接口相关的内容,实现类及其在DispatcherServlet中执行的顺序,接 ...

  7. springMVC源码分析--AbstractHandlerMapping(二)

    上一篇博客springMVC源码分析--HandlerMapping(一)中我们简单的介绍了HandlerMapping,接下来我们介绍一下它的抽象实现类AbstractHandlerMapping

  8. springMVC源码分析--HandlerMapping(一)

    HandlerMapping的工作就是为每个请求找到合适的请求找到一个处理器handler,其实现机制简单来说就是维持了一个url到Controller关系的Map结构,其提供的实际功能也是根据req ...

  9. springMVC源码分析--拦截器HandlerExecutionChain(三)

    上一篇博客springMVC源码分析--HandlerInterceptor拦截器调用过程(二)中我们介绍了HandlerInterceptor的执行调用地方,最终HandlerInterceptor ...

随机推荐

  1. MySQL · 引擎特性 · InnoDB 同步机制

    前言 现代操作系统以及硬件基本都支持并发程序,而在并发程序设计中,各个进程或者线程需要对公共变量的访问加以制约,此外,不同的进程或者线程需要协同工作以完成特征的任务,这就需要一套完善的同步机制,在Li ...

  2. kafka知识体系-kafka设计和原理分析-kafka leader选举

    kafka leader选举 一条消息只有被ISR中的所有follower都从leader复制过去才会被认为已提交.这样就避免了部分数据被写进了leader,还没来得及被任何follower复制就宕机 ...

  3. 【swift,oc】ios开发中巧用自动布局设置自定义cell的高度

    ios开发中,遇到自定义高度不定的cell的时候,我们通常的做法是抽取一个frame类,在frame类中预算好高度,再返回. 但是苹果出来自动布局之后...春天来了!!来看看怎么巧用自动布局设置自定义 ...

  4. 计蒜客NOIP模拟赛5 D1T1 机智的 AmyZhi

    那年一个雨季,AmyZhi 在校门外弯身买参考书. 这时 SiriusRen 走过来,一言不合甩给她一道“自认为”很难的题: --------------- 给你一个数字 NN(NN 的范围是 11  ...

  5. ●POJ 1741 Tree

    题链: http://poj.org/problem?id=1741题解: 树上点分治. 入门题,不多说了. 代码: #include<cstdio> #include<cstrin ...

  6. ●BZOJ 1396 识别子串

    题链: http://www.joyoi.cn/problem/tyvj-2301(非权限OI患者,苟且在joyoi...)题解: 后缀自动机,线段树 先对原串建立后缀自动机,不难发现, 会影响答案是 ...

  7. ●BOZJ 4456 [Zjoi2016]旅行者

    题链: http://www.lydsy.com/JudgeOnline/problem.php?id=4456 题解: 分治好题.大致做法如下:对于一开始的矩形区域,过较长边的中点把矩形区域分为两个 ...

  8. 【CodeVs 6128 Lence的方块们】

    ·希望除了内部人员以外能有人通过这道题,因为这是大米饼第一次改编的题 ·我所见到的"本题原版"的题解也很少,搜索一下应该是: #include<stdio.h> #in ...

  9. poj 3693 后缀数组 重复次数最多的连续重复子串

    Maximum repetition substring Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8669   Acc ...

  10. Codeforces Round#403 (Div. 1)

    唉,昨天晚上迷迷糊糊地去打cf,结果fst两题,掉回蓝了... A.Andryusha and Colored Balloons 题意:给定一棵树,任意两个距离小等于二的点不能染相同的颜色,求最小颜色 ...