Dedicated, "_"-prefixed log category for request mappings

Closes gh-26539

Author: rstoyanchev

spring-core/src/main/java/org/springframework/core/log/LogDelegateFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -63,15 +63,28 @@ public static Log getCompositeLog(Log primaryLogger, Log secondaryLogger, Log...
 	}
 
 	/**
-	 * Create a "hidden" logger whose name is intentionally prefixed with "_"
-	 * because its output is either too verbose or otherwise deemed as optional
-	 * or unnecessary to see at any log level by default under the normal package
-	 * based log hierarchy.
+	 * Create a "hidden" logger with a category name prefixed with "_", thus
+	 * precluding it from being enabled together with other log categories from
+	 * the same package. This is useful for specialized output that is either
+	 * too verbose or otherwise optional or unnecessary to see all the time.
 	 * @param clazz the class for which to create a logger
-	 * @return a logger for the hidden category ("_" + fully-qualified class name)
+	 * @return a Log with the category {@code "_" + fully-qualified class name}
 	 */
 	public static Log getHiddenLog(Class<?> clazz) {
-		return LogFactory.getLog("_" + clazz.getName());
+		return getHiddenLog(clazz.getName());
+	}
+
+	/**
+	 * Create a "hidden" logger with a category name prefixed with "_", thus
+	 * precluding it from being enabled together with other log categories from
+	 * the same package. This is useful for specialized output that is either
+	 * too verbose or otherwise optional or unnecessary to see all the time.
+	 * @param category the log category to use
+	 * @return a Log with the category {@code "_" + category}
+	 * @since 5.3.5
+	 */
+	public static Log getHiddenLog(String category) {
+		return LogFactory.getLog("_" + category);
 	}
 
 }

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/support/RouterFunctionMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -128,12 +128,15 @@ private List<RouterFunction<?>> routerFunctions() {
 	}
 
 	private void logRouterFunctions(List<RouterFunction<?>> routerFunctions) {
-		if (logger.isDebugEnabled()) {
+		if (mappingsLogger.isDebugEnabled()) {
+			routerFunctions.forEach(function -> mappingsLogger.debug("Mapped " + function));
+		}
+		else if (logger.isDebugEnabled()) {
 			int total = routerFunctions.size();
 			String message = total + " RouterFunction(s) in " + formatMappingName();
 			if (logger.isTraceEnabled()) {
 				if (total > 0) {
-					routerFunctions.forEach(routerFunction -> logger.trace("Mapped " + routerFunction));
+					routerFunctions.forEach(function -> logger.trace("Mapped " + function));
 				}
 				else {
 					logger.trace(message);

spring-webflux/src/main/java/org/springframework/web/reactive/handler/AbstractHandlerMapping.java

@@ -18,11 +18,13 @@
 
 import java.util.Map;
 
+import org.apache.commons.logging.Log;
 import reactor.core.publisher.Mono;
 
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.context.support.ApplicationObjectSupport;
 import org.springframework.core.Ordered;
+import org.springframework.core.log.LogDelegateFactory;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -51,6 +53,10 @@ public abstract class AbstractHandlerMapping extends ApplicationObjectSupport
 
 	private static final WebHandler NO_OP_HANDLER = exchange -> Mono.empty();
 
+	/** Dedicated "hidden" logger for request mappings. */
+	protected final Log mappingsLogger =
+			LogDelegateFactory.getHiddenLog(HandlerMapping.class.getName() + ".Mappings");
+
 
 	private final PathPatternParser patternParser;
 

spring-webflux/src/main/java/org/springframework/web/reactive/handler/SimpleUrlHandlerMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -158,9 +158,16 @@ protected void registerHandlers(Map<String, Object> urlMap) throws BeansExceptio
 				}
 				registerHandler(url, handler);
 			}
-			if (logger.isDebugEnabled()) {
-				logger.debug("Patterns " + getHandlerMap().keySet() + " in " + formatMappingName());
-			}
+			logMappings();
+		}
+	}
+
+	private void logMappings() {
+		if (mappingsLogger.isDebugEnabled()) {
+			mappingsLogger.debug(formatMappingName() + " " + getHandlerMap());
+		}
+		else if (logger.isDebugEnabled()) {
+			logger.debug("Patterns " + getHandlerMap().keySet() + " in " + formatMappingName());
 		}
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/resource/ResourceWebHandler.java

@@ -619,7 +619,9 @@ private Object formatLocations() {
 			return this.locationValues.stream().collect(Collectors.joining("\", \"", "[\"", "\"]"));
 		}
 		else if (!this.locations.isEmpty()) {
-			return "[" + this.locations + "]";
+			return "[" + this.locations.toString()
+					.replaceAll("class path resource", "Classpath")
+					.replaceAll("ServletContext resource", "ServletContext") + "]";
 		}
 		return Collections.emptyList();
 	}

spring-webflux/src/main/java/org/springframework/web/reactive/result/method/AbstractHandlerMethodMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -211,6 +211,9 @@ protected void detectHandlerMethods(final Object handler) {
 			if (logger.isTraceEnabled()) {
 				logger.trace(formatMappings(userType, methods));
 			}
+			else if (mappingsLogger.isDebugEnabled()) {
+				mappingsLogger.debug(formatMappings(userType, methods));
+			}
 			methods.forEach((method, mapping) -> {
 				Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
 				registerHandlerMethod(handler, invocableMethod, mapping);

spring-webmvc/src/main/java/org/springframework/web/servlet/function/support/RouterFunctionMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -153,14 +153,31 @@ private void initRouterFunction() {
 				(this.detectHandlerFunctionsInAncestorContexts ?
 						BeanFactoryUtils.beansOfTypeIncludingAncestors(applicationContext, RouterFunction.class) :
 						applicationContext.getBeansOfType(RouterFunction.class));
-
 		List<RouterFunction> routerFunctions = new ArrayList<>(beans.values());
-		if (!CollectionUtils.isEmpty(routerFunctions) && logger.isInfoEnabled()) {
-			routerFunctions.forEach(routerFunction -> logger.info("Mapped " + routerFunction));
+		this.routerFunction = routerFunctions.stream().reduce(RouterFunction::andOther).orElse(null);
+		logRouterFunctions(routerFunctions);
+	}
+
+	@SuppressWarnings("rawtypes")
+	private void logRouterFunctions(List<RouterFunction> routerFunctions) {
+		if (mappingsLogger.isDebugEnabled()) {
+			routerFunctions.forEach(function -> mappingsLogger.debug("Mapped " + function));
+		}
+		else if (logger.isDebugEnabled()) {
+			int total = routerFunctions.size();
+			String message = total + " RouterFunction(s) in " + formatMappingName();
+			if (logger.isTraceEnabled()) {
+				if (total > 0) {
+					routerFunctions.forEach(function -> logger.trace("Mapped " + function));
+				}
+				else {
+					logger.trace(message);
+				}
+			}
+			else if (total > 0) {
+				logger.debug(message);
+			}
 		}
-		this.routerFunction = routerFunctions.stream()
-				.reduce(RouterFunction::andOther)
-				.orElse(null);
 	}
 
 	/**

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractDetectingUrlHandlerMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -82,7 +82,10 @@ protected void detectHandlers() throws BeansException {
 			}
 		}
 
-		if ((logger.isDebugEnabled() && !getHandlerMap().isEmpty()) || logger.isTraceEnabled()) {
+		if (mappingsLogger.isDebugEnabled()) {
+			mappingsLogger.debug(formatMappingName() + " " + getHandlerMap());
+		}
+		else if ((logger.isDebugEnabled() && !getHandlerMap().isEmpty()) || logger.isTraceEnabled()) {
 			logger.debug("Detected " + getHandlerMap().size() + " mappings in " + formatMappingName());
 		}
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMapping.java

@@ -26,10 +26,13 @@
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.apache.commons.logging.Log;
+
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.BeanNameAware;
 import org.springframework.core.Ordered;
+import org.springframework.core.log.LogDelegateFactory;
 import org.springframework.http.server.RequestPath;
 import org.springframework.lang.Nullable;
 import org.springframework.util.AntPathMatcher;
@@ -75,6 +78,11 @@
 public abstract class AbstractHandlerMapping extends WebApplicationObjectSupport
 		implements HandlerMapping, Ordered, BeanNameAware {
 
+	/** Dedicated "hidden" logger for request mappings. */
+	protected final Log mappingsLogger =
+			LogDelegateFactory.getHiddenLog(HandlerMapping.class.getName() + ".Mappings");
+
+
 	@Nullable
 	private Object defaultHandler;
 
@@ -358,7 +366,7 @@ public void setBeanName(String name) {
 	}
 
 	protected String formatMappingName() {
-		return this.beanName != null ? "'" + this.beanName + "'" : "<unknown>";
+		return this.beanName != null ? "'" + this.beanName + "'" : getClass().getName();
 	}
 
 

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java

@@ -290,6 +290,9 @@ protected void detectHandlerMethods(Object handler) {
 			if (logger.isTraceEnabled()) {
 				logger.trace(formatMappings(userType, methods));
 			}
+			else if (mappingsLogger.isDebugEnabled()) {
+				mappingsLogger.debug(formatMappings(userType, methods));
+			}
 			methods.forEach((method, mapping) -> {
 				Method invocableMethod = AopUtils.selectInvocableMethod(method, userType);
 				registerHandlerMethod(handler, invocableMethod, mapping);

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractUrlHandlerMapping.java

@@ -206,7 +206,7 @@ protected Object lookupHandler(
 		if (matches.size() > 1) {
 			matches.sort(PathPattern.SPECIFICITY_COMPARATOR);
 			if (logger.isTraceEnabled()) {
-				logger.debug("Matching patterns " + matches);
+				logger.trace("Matching patterns " + matches);
 			}
 		}
 		PathPattern pattern = matches.get(0);

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/SimpleUrlHandlerMapping.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -161,17 +161,31 @@ protected void registerHandlers(Map<String, Object> urlMap) throws BeansExceptio
 				}
 				registerHandler(url, handler);
 			});
-			if (logger.isDebugEnabled()) {
-				List<String> patterns = new ArrayList<>();
-				if (getRootHandler() != null) {
-					patterns.add("/");
-				}
-				if (getDefaultHandler() != null) {
-					patterns.add("/**");
-				}
-				patterns.addAll(getHandlerMap().keySet());
-				logger.debug("Patterns " + patterns + " in " + formatMappingName());
+			logMappings();
+		}
+	}
+
+	private void logMappings() {
+		if (mappingsLogger.isDebugEnabled()) {
+			Map<String, Object> map = new LinkedHashMap<>(getHandlerMap());
+			if (getRootHandler() != null) {
+				map.put("/", getRootHandler());
+			}
+			if (getDefaultHandler() != null) {
+				map.put("/**", getDefaultHandler());
+			}
+			mappingsLogger.debug(formatMappingName() + " " + map);
+		}
+		else if (logger.isDebugEnabled()) {
+			List<String> patterns = new ArrayList<>();
+			if (getRootHandler() != null) {
+				patterns.add("/");
+			}
+			if (getDefaultHandler() != null) {
+				patterns.add("/**");
 			}
+			patterns.addAll(getHandlerMap().keySet());
+			logger.debug("Patterns " + patterns + " in " + formatMappingName());
 		}
 	}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceHttpRequestHandler.java

@@ -800,6 +800,10 @@ protected void setHeaders(HttpServletResponse response, Resource resource, @Null
 
 	@Override
 	public String toString() {
-		return "ResourceHttpRequestHandler " + getLocations();
+		return "ResourceHttpRequestHandler " +
+				getLocations().toString()
+						.replaceAll("class path resource", "Classpath")
+						.replaceAll("ServletContext resource", "ServletContext");
 	}
+
 }