Support for static field access on non-public enums

Issue: SPR-16284

Author: jhoeller

spring-beans/src/main/java/org/springframework/beans/TypeConverterDelegate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 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.
@@ -346,6 +346,7 @@ private Object attemptToConvertStringToEnum(Class<?> requiredType, String trimme
 			// to be checked, hence we don't return it right away.
 			try {
 				Field enumField = requiredType.getField(trimmedValue);
+				ReflectionUtils.makeAccessible(enumField);
 				convertedValue = enumField.get(null);
 			}
 			catch (Throwable ex) {

spring-beans/src/test/java/org/springframework/beans/BeanWrapperEnumTests.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.
@@ -173,4 +173,32 @@ public void testStandardEnumMapWithAutoGrowing() {
 		assertEquals(new Integer(1), gb.getStandardEnumMap().get(CustomEnum.VALUE_1));
 	}
 
+	@Test
+	public void testNonPublicEnum() {
+		NonPublicEnumHolder holder = new NonPublicEnumHolder();
+		BeanWrapper bw = new BeanWrapperImpl(holder);
+		bw.setPropertyValue("nonPublicEnum", "VALUE_1");
+		assertEquals(NonPublicEnum.VALUE_1, holder.getNonPublicEnum());
+	}
+
+
+	enum NonPublicEnum {
+
+		VALUE_1, VALUE_2;
+	}
+
+
+	static class NonPublicEnumHolder {
+
+		private NonPublicEnum nonPublicEnum;
+
+		public NonPublicEnum getNonPublicEnum() {
+			return nonPublicEnum;
+		}
+
+		public void setNonPublicEnum(NonPublicEnum nonPublicEnum) {
+			this.nonPublicEnum = nonPublicEnum;
+		}
+	}
+
 }

spring-beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.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.
@@ -2736,6 +2736,16 @@ public void emptyJavaUtilOptionalBean() {
 		assertSame(Optional.empty(), bf.getBean(Optional.class));
 	}
 
+	@Test
+	public void testNonPublicEnum() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		RootBeanDefinition bd = new RootBeanDefinition(NonPublicEnumHolder.class);
+		bd.getConstructorArgumentValues().addGenericArgumentValue("VALUE_1");
+		bf.registerBeanDefinition("holderBean", bd);
+		NonPublicEnumHolder holder = (NonPublicEnumHolder) bf.getBean("holderBean");
+		assertEquals(NonPublicEnum.VALUE_1, holder.getNonPublicEnum());
+	}
+
 	/**
 	 * Test that by-type bean lookup caching is working effectively by searching for a
 	 * bean of type B 10K times within a container having 1K additional beans of type A.
@@ -3263,4 +3273,24 @@ public boolean isSingleton() {
 		}
 	}
 
+
+	enum NonPublicEnum {
+
+		VALUE_1, VALUE_2;
+	}
+
+
+	static class NonPublicEnumHolder {
+
+		final NonPublicEnum nonPublicEnum;
+
+		public NonPublicEnumHolder(NonPublicEnum nonPublicEnum) {
+			this.nonPublicEnum = nonPublicEnum;
+		}
+
+		public NonPublicEnum getNonPublicEnum() {
+			return nonPublicEnum;
+		}
+	}
+
 }