Improved logging for @MessageMapping methods

Closes gh-20564

Author: rstoyanchev

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/AbstractMethodMessageHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -18,6 +18,7 @@
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
@@ -26,6 +27,8 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -309,12 +312,27 @@ protected final void detectHandlerMethods(final Object handler) {
 			Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
 					(MethodIntrospector.MetadataLookup<T>) method -> getMappingForMethod(method, userType));
 			if (logger.isDebugEnabled()) {
-				logger.debug(methods.size() + " message handler methods found on " + userType + ": " + methods);
+				logger.debug(formatMappings(userType, methods));
 			}
 			methods.forEach((key, value) -> registerHandlerMethod(handler, key, value));
 		}
 	}
 
+	private String formatMappings(Class<?> userType, Map<Method, T> methods) {
+		String formattedType = Arrays.stream(ClassUtils.getPackageName(userType).split("\\."))
+				.map(p -> p.substring(0, 1))
+				.collect(Collectors.joining(".", "", "." + userType.getSimpleName()));
+		Function<Method, String> methodFormatter = method -> Arrays.stream(method.getParameterTypes())
+				.map(Class::getSimpleName)
+				.collect(Collectors.joining(",", "(", ")"));
+		return methods.entrySet().stream()
+				.map(e -> {
+					Method method = e.getKey();
+					return e.getValue() + ": " + method.getName() + methodFormatter.apply(method);
+				})
+				.collect(Collectors.joining("\n\t", "\n\t" + formattedType + ":" + "\n\t", ""));
+	}
+
 	/**
 	 * Provide the mapping for a handler method.
 	 * @param method the method to provide a mapping for
@@ -344,9 +362,6 @@ protected void registerHandlerMethod(Object handler, Method method, T mapping) {
 		}
 
 		this.handlerMethods.put(mapping, newHandlerMethod);
-		if (logger.isTraceEnabled()) {
-			logger.trace("Mapped \"" + mapping + "\" onto " + newHandlerMethod);
-		}
 
 		for (String pattern : getDirectLookupDestinations(mapping)) {
 			this.destinationLookup.add(pattern, mapping);

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/reactive/AbstractMethodMessageHandler.java

@@ -18,14 +18,17 @@
 
 import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -284,12 +287,27 @@ protected final void detectHandlerMethods(Object handler) {
 			Map<Method, T> methods = MethodIntrospector.selectMethods(userType,
 					(MethodIntrospector.MetadataLookup<T>) method -> getMappingForMethod(method, userType));
 			if (logger.isDebugEnabled()) {
-				logger.debug(methods.size() + " message handler methods found on " + userType + ": " + methods);
+				logger.debug(formatMappings(userType, methods));
 			}
 			methods.forEach((key, value) -> registerHandlerMethod(handler, key, value));
 		}
 	}
 
+	private String formatMappings(Class<?> userType, Map<Method, T> methods) {
+		String formattedType = Arrays.stream(ClassUtils.getPackageName(userType).split("\\."))
+				.map(p -> p.substring(0, 1))
+				.collect(Collectors.joining(".", "", "." + userType.getSimpleName()));
+		Function<Method, String> methodFormatter = method -> Arrays.stream(method.getParameterTypes())
+				.map(Class::getSimpleName)
+				.collect(Collectors.joining(",", "(", ")"));
+		return methods.entrySet().stream()
+				.map(e -> {
+					Method method = e.getKey();
+					return e.getValue() + ": " + method.getName() + methodFormatter.apply(method);
+				})
+				.collect(Collectors.joining("\n\t", "\n\t" + formattedType + ":" + "\n\t", ""));
+	}
+
 	/**
 	 * Obtain the mapping for the given method, if any.
 	 * @param method the method to check
@@ -322,9 +340,6 @@ protected final void registerHandlerMethod(Object handler, Method method, T mapp
 		}
 
 		this.handlerMethods.put(mapping, newHandlerMethod);
-		if (logger.isTraceEnabled()) {
-			logger.trace("Mapped \"" + mapping + "\" onto " + newHandlerMethod);
-		}
 
 		for (String pattern : getDirectLookupMappings(mapping)) {
 			this.destinationLookup.add(pattern, mapping);