Spring MVC的handlermapping之RequestMappingHandlerMapping初始化

 1     public void afterPropertiesSet() { //实现了InitializingBean接口的方法，进行初始化的入口。
 2         this.initHandlerMethods();
 3     }
 4 
 5     protected void initHandlerMethods() {
 6         if (this.logger.isDebugEnabled()) {
 7             this.logger.debug("Looking for request mappings in application context: " + this.getApplicationContext());
 8         }
 9 　　　　 //扫描应用下所有Object类
10         String[] beanNames = this.detectHandlerMethodsInAncestorContexts ? BeanFactoryUtils.beanNamesForTypeIncludingAncestors(this.getApplicationContext(), Object.class) : this.getApplicationContext().getBeanNamesForType(Object.class);
11         String[] arr$ = beanNames;
12         int len$ = beanNames.length;
13 
14         for(int i$ = 0; i$ < len$; ++i$) {
15             String beanName = arr$[i$];
16             if (this.isHandler(this.getApplicationContext().getType(beanName))) { //ishandler由子类实现，是个钩子方法，让子类实现自己的逻辑
17                 this.detectHandlerMethods(beanName);
18             }
19         }
20 
21         this.handlerMethodsInitialized(this.getHandlerMethods());//初始化处理器对象，目前是钩子方法，但是也没有子类实现这个方法
22     }

1     protected boolean isHandler(Class<?> beanType) { //非常简单， 就是看这个类有没有Controller或者RequestMapping注解，有一个就行
2         return AnnotationUtils.findAnnotation(beanType, Controller.class) != null || AnnotationUtils.findAnnotation(beanType, RequestMapping.class) != null;
3     }

 1     protected void detectHandlerMethods(Object handler) { //开始注册handler
 2         Class<?> handlerType = handler instanceof String ? this.getApplicationContext().getType((String)handler) : handler.getClass();
 3         final Class<?> userType = ClassUtils.getUserClass(handlerType);
　　　　　　//这块是获取handelr的所有方法，但是有一个过滤器，就是把有匹配条件的的method获取到
 4         Set<Method> methods = HandlerMethodSelector.selectMethods(userType, new MethodFilter() {
 5             public boolean matches(Method method) {
 6                 return AbstractHandlerMethodMapping.this.getMappingForMethod(method, userType) != null;//getMappingForMethod钩子方法，子类实现
 7             }
 8         });
 9         Iterator i$ = methods.iterator();
10         //遍历method 进行注册。
11         while(i$.hasNext()) {
12             Method method = (Method)i$.next();
13             T mapping = this.getMappingForMethod(method, userType);
14             this.registerHandlerMethod(handler, method, mapping);
15         }
16 
17     }

 1     protected RequestMappingInfo getMappingForMethod(Method method, Class<?> handlerType) { 
 2         RequestMappingInfo info = null; //获取方法上的RequestMapping注解信息
 3         RequestMapping methodAnnotation = (RequestMapping)AnnotationUtils.findAnnotation(method, RequestMapping.class);
 4         if (methodAnnotation != null) {
 5             RequestCondition<?> methodCondition = this.getCustomMethodCondition(method);
 6             info = this.createRequestMappingInfo(methodAnnotation, methodCondition); 构造匹配条件
　　　　　　　　 // 获取类上的面RequestHandlerMapping注解信息
 7             RequestMapping typeAnnotation = (RequestMapping)AnnotationUtils.findAnnotation(handlerType, RequestMapping.class);
 8             if (typeAnnotation != null) {
 9                 RequestCondition<?> typeCondition = this.getCustomTypeCondition(handlerType);
10                 info = this.createRequestMappingInfo(typeAnnotation, typeCondition).combine(info); 构造匹配条件，同方法的进行合并
11             }
12         }
13 
14         return info;
15     }

1 public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMapping implements InitializingBean {
2     //这块实际上是两个map保存的，泛型实际上就是RequestMappingInfo,这个就是匹配条件 HanlderMethod是封装了处理器全部信息的封装类

3     private final Map<T, HandlerMethod> handlerMethods = new LinkedHashMap(); //存的是 key：匹配条件 value: 处理器
4     private final MultiValueMap<String, T> urlMap = new LinkedMultiValueMap(); //key: url value: 匹配条件

 1     protected void registerHandlerMethod(Object handler, Method method, T mapping) {
 2         HandlerMethod handlerMethod;
 3         if (handler instanceof String) {
 4             String beanName = (String)handler;
 5             handlerMethod = new HandlerMethod(beanName, this.getApplicationContext(), method);
 6         } else {
 7             handlerMethod = new HandlerMethod(handler, method);
 8         }
 9 
10         HandlerMethod oldHandlerMethod = (HandlerMethod)this.handlerMethods.get(mapping);
11         if (oldHandlerMethod != null && !oldHandlerMethod.equals(handlerMethod)) { //不允许存在一个mapping对应多个handlerMethod
12             throw new IllegalStateException("Ambiguous mapping found. Cannot map ‘" + handlerMethod.getBean() + "‘ bean method \n" + handlerMethod + "\nto " + mapping + ": There is already ‘" + oldHandlerMethod.getBean() + "‘ bean method\n" + oldHandlerMethod + " mapped.");
13         } else {
14             this.handlerMethods.put(mapping, handlerMethod); //存放第一个映射集合
15             if (this.logger.isInfoEnabled()) {
16                 this.logger.info("Mapped \"" + mapping + "\" onto " + handlerMethod);
17             }
18 
19             Set<String> patterns = this.getMappingPathPatterns(mapping); //获取方法的URL
20             Iterator i$ = patterns.iterator();
21 
22             while(i$.hasNext()) {
23                 String pattern = (String)i$.next();
24                 if (!this.getPathMatcher().isPattern(pattern)) { //依次放入第二个映射集合
25                     this.urlMap.add(pattern, mapping);
26                 }
27             }
28 
29         }
30     }