Support URL exclusion using UrlCleaner in Spring WebFlux adapter

sentinel-adapter/sentinel-spring-webflux-adapter/README.md

@@ -50,7 +50,7 @@ public class WebFluxConfig {
 You can register various customized callback in `WebFluxCallbackManager`:
 
 - `setBlockHandler`: register a customized `BlockRequestHandler` to handle the blocked request. The default implementation is `DefaultBlockRequestHandler`, which returns default message like `Blocked by Sentinel: FlowException`.
-- `setUrlCleaner`: used for normalization of URL. The function type is `(ServerWebExchange, String) → String`, which means `(webExchange, originalUrl) → finalUrl`.
+- `setUrlCleaner`: used for normalization of URL. The function type is `(ServerWebExchange, String) → String`, which means `(webExchange, originalUrl) → finalUrl`, if the finalUrl is `"""` or `null`, the URLs will be excluded (since Sentinel 1.7.0)..
 - `setRequestOriginParser`: used to resolve the origin from the HTTP request. The function type is `ServerWebExchange → String`.
 
 You can also refer to the demo: [sentinel-demo-spring-webflux](https://github.com/alibaba/Sentinel/tree/master/sentinel-demo/sentinel-demo-spring-webflux).

sentinel-adapter/sentinel-spring-webflux-adapter/src/main/java/com/alibaba/csp/sentinel/adapter/spring/webflux/SentinelWebFluxFilter.java

@@ -22,6 +22,7 @@
 import com.alibaba.csp.sentinel.adapter.reactor.EntryConfig;
 import com.alibaba.csp.sentinel.adapter.reactor.SentinelReactorTransformer;
 import com.alibaba.csp.sentinel.adapter.spring.webflux.callback.WebFluxCallbackManager;
+import com.alibaba.csp.sentinel.util.StringUtil;
 
 import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.WebFilter;
@@ -36,24 +37,23 @@ public class SentinelWebFluxFilter implements WebFilter {
 
     @Override
     public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
-        return chain.filter(exchange)
-            .transform(buildSentinelTransformer(exchange));
-    }
-
-    private SentinelReactorTransformer<Void> buildSentinelTransformer(ServerWebExchange exchange) {
         // Maybe we can get the URL pattern elsewhere via:
         // exchange.getAttributeOrDefault(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE, path)
-
         String path = exchange.getRequest().getPath().value();
-        String finalPath = Optional.ofNullable(WebFluxCallbackManager.getUrlCleaner())
-            .map(f -> f.apply(exchange, path))
-            .orElse(path);
+
+        String finalPath = WebFluxCallbackManager.getUrlCleaner().apply(exchange, path);
+        if (StringUtil.isEmpty(finalPath)) {
+            return chain.filter(exchange);
+        }
+        return chain.filter(exchange).transform(buildSentinelTransformer(exchange, finalPath));
+    }
+
+    private SentinelReactorTransformer<Void> buildSentinelTransformer(ServerWebExchange exchange, String finalPath) {
         String origin = Optional.ofNullable(WebFluxCallbackManager.getRequestOriginParser())
             .map(f -> f.apply(exchange))
             .orElse(EMPTY_ORIGIN);
 
-        return new SentinelReactorTransformer<>(
-            new EntryConfig(finalPath, EntryType.IN, new ContextConfig(finalPath, origin)));
+        return new SentinelReactorTransformer<>(new EntryConfig(finalPath, EntryType.IN, new ContextConfig(finalPath, origin)));
     }
 
     private static final String EMPTY_ORIGIN = "";

sentinel-adapter/sentinel-spring-webflux-adapter/src/test/java/com/alibaba/csp/sentinel/adapter/spring/webflux/SentinelWebFluxIntegrationTest.java

@@ -101,6 +101,26 @@ public void testCustomizedUrlCleaner() throws Exception {
         WebFluxCallbackManager.resetUrlCleaner();
     }
 
+    @Test
+    public void testCustomizedIgnoreUrlCleaner() throws Exception {
+        final String fooPrefix = "/foo/";
+        String url1 = fooPrefix + 1;
+        WebFluxCallbackManager.setUrlCleaner(((exchange, originUrl) -> {
+            if (originUrl.startsWith(fooPrefix)) {
+                return "";
+            }
+            return originUrl;
+        }));
+        this.webClient.get()
+                .uri(url1)
+                .exchange()
+                .expectStatus().isOk()
+                .expectBody(String.class).isEqualTo("Hello 1");
+
+        assertNull(ClusterBuilderSlot.getClusterNode(url1));
+        WebFluxCallbackManager.resetUrlCleaner();
+    }
+
     @Test
     public void testCustomizedBlockRequestHandler() throws Exception {
         String url = "/error";
@@ -166,4 +186,4 @@ public void cleanUp() {
         FlowRuleManager.loadRules(new ArrayList<>());
         ClusterBuilderSlot.resetClusterNodes();
     }
-}
+}