SpringFactoriesLoader tolerates whitespace around class names

Issue: SPR-17413

(cherry picked from commit dd2ce20687)

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

@@ -57,14 +57,14 @@ import org.springframework.util.StringUtils;
  */
 public abstract class SpringFactoriesLoader {
 
-	private static final Log logger = LogFactory.getLog(SpringFactoriesLoader.class);
-
 	/**
 	 * The location to look for factories.
 	 * <p>Can be present in multiple JAR files.
 	 */
 	public static final String FACTORIES_RESOURCE_LOCATION = "META-INF/spring.factories";
 
+	private static final Log logger = LogFactory.getLog(SpringFactoriesLoader.class);
+
 
 	/**
 	 * Load and instantiate the factory implementations of the given type from
@@ -74,9 +74,9 @@ 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, ClassLoader classLoader) {
 		Assert.notNull(factoryClass, "'factoryClass' must not be null");
@@ -103,8 +103,8 @@ public abstract class SpringFactoriesLoader {
 	 * @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, ClassLoader classLoader) {
 		String factoryClassName = factoryClass.getName();
@@ -115,14 +115,16 @@ public abstract class SpringFactoriesLoader {
 			while (urls.hasMoreElements()) {
 				URL url = urls.nextElement();
 				Properties properties = PropertiesLoaderUtils.loadProperties(new UrlResource(url));
-				String factoryClassNames = properties.getProperty(factoryClassName);
-				result.addAll(Arrays.asList(StringUtils.commaDelimitedListToStringArray(factoryClassNames)));
+				String propertyValue = properties.getProperty(factoryClassName);
+				for (String factoryName : StringUtils.commaDelimitedListToStringArray(propertyValue)) {
+					result.add(factoryName.trim());
+				}
 			}
 			return result;
 		}
 		catch (IOException ex) {
-			throw new IllegalArgumentException("Unable to load [" + factoryClass.getName() +
-					"] factories from location [" + FACTORIES_RESOURCE_LOCATION + "]", ex);
+			throw new IllegalArgumentException("Unable to load factories from location [" +
+					FACTORIES_RESOURCE_LOCATION + "]", ex);
 		}
 	}
 

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 class SpringFactoriesLoaderTests {
 	}
 
 	@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=\