源码位置
spring-cloud-gateway-core-2.0.1.RELEASE-sources.jar!/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java

过滤方法

    @Overridepublic Predicate<ServerWebExchange> apply(Config config) {synchronized (this.pathPatternParser) {//仅在第一次调用路由时执行，将pattern字符串转PathPattern对象config.pathPattern = this.pathPatternParser.parse(config.pattern);}return exchange -> {PathContainer path = parsePath(exchange.getRequest().getURI().getPath());//path（url）转PathContainer对象   
//在此位置设置断点，每次走到需要predicate.Path过滤的路径都会进入到这里boolean match = config.pathPattern.matches(path);//路径表达式匹配判断traceMatch("Pattern", config.pathPattern.getPatternString(), path, match);if (match) {PathMatchInfo uriTemplateVariables = config.pathPattern.matchAndExtract(path);exchange.getAttributes().put(URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVariables);return true;} else {return false;}};}

手动测试表达式效果
new PathPatternParser().parse("/sys*/**").matches(path)

匹配/sys-aaa/sadf、/sysf3s/sa等格式路径

 

进入逻辑：
onNext:reactor-core-3.1.10.RELEASE-sources.jar!/reactor/core/publisher/MonoFilterWhen.java
从这里进入gateway
lookupRoute:spring-cloud-gateway-core-2.0.1.RELEASE-sources.jar!/org/springframework/cloud/gateway/handler/RoutePredicateHandlerMapping.java
进入
toAsyncPredicate:spring-cloud-gateway-core-2.0.1.RELEASE-sources.jar!/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java
最后进入
lambda$apply$:spring-cloud-gateway-core-2.0.1.RELEASE-sources.jar!/org/springframework/cloud/gateway/handler/predicate/PathRoutePredicateFactory.java