SpringMVC源码解读

使用@RequestMapping注解时,配置的信息最后都设置到了RequestMappingInfo中.

RequestMappingInfo封装了PatternsRequestCondition,RequestMethodsRequestCondition,ParamsRequestCondition等,所以自己不干活,所有的活都是委托给具体的condition处理.

先看下封装的RequestCondition吧,之前的文章将的比较细了,不清楚各个类具体是做什么的,可以移步这里<SpringMVC源码解读 - RequestMapping注解实现解读 - RequestCondition体系>

package org.springframework.web.servlet.mvc.method;
public final class RequestMappingInfo implements RequestCondition<RequestMappingInfo> {

    private final PatternsRequestCondition patternsCondition;

    private final RequestMethodsRequestCondition methodsCondition;

    private final ParamsRequestCondition paramsCondition;

    private final HeadersRequestCondition headersCondition;

    private final ConsumesRequestCondition consumesCondition;

    private final ProducesRequestCondition producesCondition;

    private final RequestConditionHolder customConditionHolder;
}

初始化没什么好看的,直接看接口的实现吧.

貌似combine也没啥料,就是分别委托

    /**
     * Combines "this" request mapping info (i.e. the current instance) with another request mapping info instance.
     * <p>Example: combine type- and method-level request mappings.
     * @return a new request mapping info instance; never {@code null}
     */
    public RequestMappingInfo combine(RequestMappingInfo other) {
        PatternsRequestCondition patterns = this.patternsCondition.combine(other.patternsCondition);
        RequestMethodsRequestCondition methods = this.methodsCondition.combine(other.methodsCondition);
        ParamsRequestCondition params = this.paramsCondition.combine(other.paramsCondition);
        HeadersRequestCondition headers = this.headersCondition.combine(other.headersCondition);
        ConsumesRequestCondition consumes = this.consumesCondition.combine(other.consumesCondition);
        ProducesRequestCondition produces = this.producesCondition.combine(other.producesCondition);
        RequestConditionHolder custom = this.customConditionHolder.combine(other.customConditionHolder);

        return new RequestMappingInfo(patterns, methods, params, headers, consumes, produces, custom.getCondition());
    }

getMatchingCondition只是体现出可能基于性能消耗的考虑,把PatternsRequestCondition和RequestConditionHolder的比较放到后面单独处理了.

    /**
     * Checks if all conditions in this request mapping info match the provided request and returns
     * a potentially new request mapping info with conditions tailored to the current request.
     * <p>For example the returned instance may contain the subset of URL patterns that match to
     * the current request, sorted with best matching patterns on top.
     * @return a new instance in case all conditions match; or {@code null} otherwise
     */
    public RequestMappingInfo getMatchingCondition(HttpServletRequest request) {
        RequestMethodsRequestCondition methods = methodsCondition.getMatchingCondition(request);
        ParamsRequestCondition params = paramsCondition.getMatchingCondition(request);
        HeadersRequestCondition headers = headersCondition.getMatchingCondition(request);
        ConsumesRequestCondition consumes = consumesCondition.getMatchingCondition(request);
        ProducesRequestCondition produces = producesCondition.getMatchingCondition(request);

        if (methods == null || params == null || headers == null || consumes == null || produces == null) {
            return null;
        }

        PatternsRequestCondition patterns = patternsCondition.getMatchingCondition(request);
        if (patterns == null) {
            return null;
        }

        RequestConditionHolder custom = customConditionHolder.getMatchingCondition(request);
        if (custom == null) {
            return null;
        }

        return new RequestMappingInfo(patterns, methods, params, headers, consumes, produces, custom.getCondition());
    }

compareTo就是排了个不同RequestCondition的优先级

    /**
     * Compares "this" info (i.e. the current instance) with another info in the context of a request.
     * <p>Note: it is assumed both instances have been obtained via
     * {@link #getMatchingCondition(HttpServletRequest)} to ensure they have conditions with
     * content relevant to current request.
     */
    public int compareTo(RequestMappingInfo other, HttpServletRequest request) {
        int result = patternsCondition.compareTo(other.getPatternsCondition(), request);
        if (result != 0) {
            return result;
        }
        result = paramsCondition.compareTo(other.getParamsCondition(), request);
        if (result != 0) {
            return result;
        }
        result = headersCondition.compareTo(other.getHeadersCondition(), request);
        if (result != 0) {
            return result;
        }
        result = consumesCondition.compareTo(other.getConsumesCondition(), request);
        if (result != 0) {
            return result;
        }
        result = producesCondition.compareTo(other.getProducesCondition(), request);
        if (result != 0) {
            return result;
        }
        result = methodsCondition.compareTo(other.getMethodsCondition(), request);
        if (result != 0) {
            return result;
        }
        result = customConditionHolder.compareTo(other.customConditionHolder, request);
        if (result != 0) {
            return result;
        }
        return 0;
    }

覆写的equals,hashCode,toString不看也罢