ClassUtils.getMostSpecificMethod uses Class.getMethod code path in case of a public method

This should be significantly faster than our standard algorithm, for a very common case. Motivated by SPR-9802, even if the fix there uses a different approach, with transaction name determination not calling getMostSpecificMethod at all anymore.

Issue: SPR-9802

org.springframework.core/src/main/java/org/springframework/util/ClassUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -462,17 +462,28 @@ public abstract class ClassUtils {
 	}
 
 	/**
-	 * Determine the name of the package of the given class:
-	 * e.g. "java.lang" for the <code>java.lang.String</code> class.
+	 * Determine the name of the package of the given class,
+	 * e.g. "java.lang" for the {@code java.lang.String} class.
 	 * @param clazz the class
 	 * @return the package name, or the empty String if the class
 	 * is defined in the default package
 	 */
 	public static String getPackageName(Class<?> clazz) {
 		Assert.notNull(clazz, "Class must not be null");
-		String className = clazz.getName();
-		int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR);
-		return (lastDotIndex != -1 ? className.substring(0, lastDotIndex) : "");
+		return getPackageName(clazz.getName());
+	}
+
+	/**
+	 * Determine the name of the package of the given fully-qualified class name,
+	 * e.g. "java.lang" for the {@code java.lang.String} class name.
+	 * @param fqClassName the fully-qualified class name
+	 * @return the package name, or the empty String if the class
+	 * is defined in the default package
+	 */
+	public static String getPackageName(String fqClassName) {
+		Assert.notNull(fqClassName, "Class name must not be null");
+		int lastDotIndex = fqClassName.lastIndexOf(PACKAGE_SEPARATOR);
+		return (lastDotIndex != -1 ? fqClassName.substring(0, lastDotIndex) : "");
 	}
 
 	/**
@@ -713,7 +724,7 @@ public abstract class ClassUtils {
 	 * Call {@link org.springframework.core.BridgeMethodResolver#findBridgedMethod}
 	 * if bridge method resolution is desirable (e.g. for obtaining metadata from
 	 * the original method definition).
-	 * <p><b>NOTE:</b>Since Spring 3.1.1, if java security settings disallow reflective
+	 * <p><b>NOTE:</b> Since Spring 3.1.1, if Java security settings disallow reflective
 	 * access (e.g. calls to {@code Class#getDeclaredMethods} etc, this implementation
 	 * will fall back to returning the originally provided method.
 	 * @param method the method to be invoked, which may come from an interface
@@ -723,17 +734,28 @@ public abstract class ClassUtils {
 	 * <code>targetClass</code> doesn't implement it or is <code>null</code>
 	 */
 	public static Method getMostSpecificMethod(Method method, Class<?> targetClass) {
-		Method specificMethod = null;
 		if (method != null && isOverridable(method, targetClass) &&
 				targetClass != null && !targetClass.equals(method.getDeclaringClass())) {
 			try {
-				specificMethod = ReflectionUtils.findMethod(targetClass, method.getName(), method.getParameterTypes());
-			} catch (AccessControlException ex) {
-				// security settings are disallowing reflective access; leave
-				// 'specificMethod' null and fall back to 'method' below
+				if (Modifier.isPublic(method.getModifiers())) {
+					try {
+						return targetClass.getMethod(method.getName(), method.getParameterTypes());
+					}
+					catch (NoSuchMethodException ex) {
+						return method;
+					}
+				}
+				else {
+					Method specificMethod =
+							ReflectionUtils.findMethod(targetClass, method.getName(), method.getParameterTypes());
+					return (specificMethod != null ? specificMethod : method);
+				}
+			}
+			catch (AccessControlException ex) {
+				// Security settings are disallowing reflective access; fall back to 'method' below.
 			}
 		}
-		return (specificMethod != null ? specificMethod : method);
+		return method;
 	}
 
 	/**
@@ -1139,5 +1161,4 @@ public abstract class ClassUtils {
 		return (className != null && className.contains(CGLIB_CLASS_SEPARATOR));
 	}
 
-
 }