SpringFactoriesLoader tolerates whitespace around class names

Issue: SPR-17413

(cherry picked from commit dd2ce20)

Author: jhoeller

spring-core/src/main/java/org/springframework/core/io/support/SpringFactoriesLoader.java

@@ -19,7 +19,6 @@
 import java.io.IOException;
 import java.net.URL;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.List;
@@ -82,9 +81,9 @@ public abstract class SpringFactoriesLoader {
 	 * to obtain all registered factory names.
 	 * @param factoryClass the interface or abstract class representing the factory
 	 * @param classLoader the ClassLoader to use for loading (can be {@code null} to use the default)
-	 * @see #loadFactoryNames
 	 * @throws IllegalArgumentException if any factory implementation class cannot
 	 * be loaded or if an error occurs while instantiating any factory
+	 * @see #loadFactoryNames
 	 */
 	public static <T> List<T> loadFactories(Class<T> factoryClass, @Nullable ClassLoader classLoader) {
 		Assert.notNull(factoryClass, "'factoryClass' must not be null");
@@ -111,8 +110,8 @@ public static <T> List<T> loadFactories(Class<T> factoryClass, @Nullable ClassLo
 	 * @param factoryClass the interface or abstract class representing the factory
 	 * @param classLoader the ClassLoader to use for loading resources; can be
 	 * {@code null} to use the default
-	 * @see #loadFactories
 	 * @throws IllegalArgumentException if an error occurs while loading factory names
+	 * @see #loadFactories
 	 */
 	public static List<String> loadFactoryNames(Class<?> factoryClass, @Nullable ClassLoader classLoader) {
 		String factoryClassName = factoryClass.getName();
@@ -135,9 +134,10 @@ private static Map<String, List<String>> loadSpringFactories(@Nullable ClassLoad
 				UrlResource resource = new UrlResource(url);
 				Properties properties = PropertiesLoaderUtils.loadProperties(resource);
 				for (Map.Entry<?, ?> entry : properties.entrySet()) {
-					List<String> factoryClassNames = Arrays.asList(
-							StringUtils.commaDelimitedListToStringArray((String) entry.getValue()));
-					result.addAll((String) entry.getKey(), factoryClassNames);
+					String factoryClassName = ((String) entry.getKey()).trim();
+					for (String factoryName : StringUtils.commaDelimitedListToStringArray((String) entry.getValue())) {
+						result.add(factoryClassName, factoryName.trim());
+					}
 				}
 			}
 			cache.put(classLoader, result);

spring-core/src/test/java/org/springframework/core/io/support/SpringFactoriesLoaderTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -33,8 +33,7 @@ public class SpringFactoriesLoaderTests {
 
 	@Test
 	public void loadFactoriesInCorrectOrder() {
-		List<DummyFactory> factories = SpringFactoriesLoader
-				.loadFactories(DummyFactory.class, null);
+		List<DummyFactory> factories = SpringFactoriesLoader.loadFactories(DummyFactory.class, null);
 		assertEquals(2, factories.size());
 		assertTrue(factories.get(0) instanceof MyDummyFactory1);
 		assertTrue(factories.get(1) instanceof MyDummyFactory2);
@@ -46,9 +45,9 @@ public void loadInvalid() {
 	}
 
 	@Test
-	public void loadPackagePrivateFactory() throws Exception {
-		List<DummyPackagePrivateFactory> factories = SpringFactoriesLoader
-				.loadFactories(DummyPackagePrivateFactory.class, null);
+	public void loadPackagePrivateFactory() {
+		List<DummyPackagePrivateFactory> factories =
+				SpringFactoriesLoader.loadFactories(DummyPackagePrivateFactory.class, null);
 		assertEquals(1, factories.size());
 		assertTrue((factories.get(0).getClass().getModifiers() & Modifier.PUBLIC) == 0);
 	}

spring-core/src/test/resources/META-INF/spring.factories

@@ -1,5 +1,5 @@
-org.springframework.core.io.support.DummyFactory=\
-org.springframework.core.io.support.MyDummyFactory2,\
+org.springframework.core.io.support.DummyFactory =\
+org.springframework.core.io.support.MyDummyFactory2, \
 org.springframework.core.io.support.MyDummyFactory1
 
 java.lang.String=\