疑问
其实我一直有一个疑问，因为我在跟自己写的controller的生命周期源码的时候，没有发现解析mapping的代码，然后我就在想，什么时候解析并加载的mapping呢？？？
结果是一个新的类 RequestMappingHandlerMapping ，惊呆了，我的小伙伴
源码跟进
我就从RequestMappingHandlerMapping的生命周期的afterPropertiesSet()方法讲起
代码语言：javascript复制//RequestMappingHandlerMapping
@Override
public void afterPropertiesSet() {
this.config = new RequestMappingInfo.BuilderConfiguration();
this.config.setUrlPathHelper(getUrlPathHelper());
this.config.setPathMatcher(getPathMatcher());
this.config.setSuffixPatternMatch(this.useSuffixPatternMatch);
this.config.setTrailingSlashMatch(this.useTrailingSlashMatch);
this.config.setRegisteredSuffixPatternMatch(this.useRegisteredSuffixPatternMatch);
this.config.setContentNegotiationManager(getContentNegotiationManager());
//调用父类的方法，跟进去--->
super.afterPropertiesSet();
}//AbstractHandlerMethodMapping
protected void initHandlerMethods() {
//遍历所有的类
for (String beanName : getCandidateBeanNames()) {
if (!beanName.startsWith(SCOPED_TARGET_NAME_PREFIX)) {
//当beanName为自定义的helloController时跟进去--->
processCandidateBean(beanName);
}
}
handlerMethodsInitialized(getHandlerMethods());
}//AbstractHandlerMethodMapping
protected void processCandidateBean(String beanName) {
Class<?> beanType = null;
try {
beanType = obtainApplicationContext().getType(beanName);
}
catch (Throwable ex) {
// An unresolvable bean type, probably from a lazy bean - let's ignore it.
if (logger.isTraceEnabled()) {
logger.trace("Could not resolve type for bean '" beanName "'", ex);
}
}
//如果此类上有Controller或者RequestMapping，则返回真
if (beanType != null && isHandler(beanType)) {
//跟进去--->
detectHandlerMethods(beanName);
}AbstractHandlerMethodMapping
protected void detectHandlerMethods(Object handler) {
Class<?> handlerType = (handler instanceof String ?
obtainApplicationContext().getType((String) handler) : handler.getClass());
if (handlerType != null) {
Class<?> userType = ClassUtils.getUserClass(handlerType);
//解析类并且获取所有带有requestMapping的方法
Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
(MethodIntrospector.MetadataLookup<T>) method -> {
try {
return getMappingForMethod(method, userType);
}
catch (Throwable ex) {
throw new IllegalStateException("Invalid mapping on handler class ["
userType.getName() "]: " method, ex);
}
});
if (logger.isTraceEnabled()) {
logger.trace(formatMappings(userType, methods));
}
//此时将method和mapping都注入到某个地方(map)中，后面就可以直接使用了
methods.forEach((method, mapping) -> {
Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
registerHandlerMethod(handler, invocableMethod, mapping);
});
}
}此时就已经明白了，并不是在自定义的controller类的生命周期内解析的mapping,而是在RequestMappingHandlerMapping 生命周期的afterPropertiesSet()方法中获取所有的controller类并解析
