ResolvableType returns clone for cached state with original local source

Issue: SPR-16210

Author: jhoeller

spring-core/src/main/java/org/springframework/core/ResolvableType.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.
@@ -117,36 +117,35 @@ public class ResolvableType implements Serializable {
 	@Nullable
 	private final ResolvableType componentType;
 
-	/**
-	 * Copy of the resolved value.
-	 */
 	@Nullable
-	private final Class<?> resolved;
+	private final Integer hash;
 
 	@Nullable
-	private final Integer hash;
+	private Class<?> resolved;
 
 	@Nullable
-	private ResolvableType superType;
+	private volatile ResolvableType superType;
 
 	@Nullable
-	private ResolvableType[] interfaces;
+	private volatile ResolvableType[] interfaces;
 
 	@Nullable
-	private ResolvableType[] generics;
+	private volatile ResolvableType[] generics;
 
 
 	/**
 	 * Private constructor used to create a new {@link ResolvableType} for cache key purposes,
 	 * with no upfront resolution.
 	 */
-	private ResolvableType(Type type, @Nullable TypeProvider typeProvider, @Nullable VariableResolver variableResolver) {
+	private ResolvableType(
+			Type type, @Nullable TypeProvider typeProvider, @Nullable VariableResolver variableResolver) {
+
 		this.type = type;
 		this.typeProvider = typeProvider;
 		this.variableResolver = variableResolver;
 		this.componentType = null;
-		this.resolved = null;
 		this.hash = calculateHashCode();
+		this.resolved = null;
 	}
 
 	/**
@@ -161,8 +160,8 @@ private ResolvableType(Type type, @Nullable TypeProvider typeProvider,
 		this.typeProvider = typeProvider;
 		this.variableResolver = variableResolver;
 		this.componentType = null;
-		this.resolved = resolveClass();
 		this.hash = hash;
+		this.resolved = resolveClass();
 	}
 
 	/**
@@ -176,8 +175,8 @@ private ResolvableType(Type type, @Nullable TypeProvider typeProvider,
 		this.typeProvider = typeProvider;
 		this.variableResolver = variableResolver;
 		this.componentType = componentType;
-		this.resolved = resolveClass();
 		this.hash = null;
+		this.resolved = resolveClass();
 	}
 
 	/**
@@ -453,10 +452,12 @@ public ResolvableType getSuperType() {
 		if (resolved == null || resolved.getGenericSuperclass() == null) {
 			return NONE;
 		}
-		if (this.superType == null) {
-			this.superType = forType(SerializableTypeWrapper.forGenericSuperclass(resolved), asVariableResolver());
+		ResolvableType superType = this.superType;
+		if (superType == null) {
+			superType = forType(SerializableTypeWrapper.forGenericSuperclass(resolved), asVariableResolver());
+			this.superType = superType;
 		}
-		return this.superType;
+		return superType;
 	}
 
 	/**
@@ -470,10 +471,12 @@ public ResolvableType[] getInterfaces() {
 		if (resolved == null || ObjectUtils.isEmpty(resolved.getGenericInterfaces())) {
 			return EMPTY_TYPES_ARRAY;
 		}
-		if (this.interfaces == null) {
-			this.interfaces = forTypes(SerializableTypeWrapper.forGenericInterfaces(resolved), asVariableResolver());
+		ResolvableType[] interfaces = this.interfaces;
+		if (interfaces == null) {
+			interfaces = forTypes(SerializableTypeWrapper.forGenericInterfaces(resolved), asVariableResolver());
+			this.interfaces = interfaces;
 		}
-		return this.interfaces;
+		return interfaces;
 	}
 
 	/**
@@ -667,24 +670,25 @@ public ResolvableType[] getGenerics() {
 		if (this == NONE) {
 			return EMPTY_TYPES_ARRAY;
 		}
-		if (this.generics == null) {
+		ResolvableType[] generics = this.generics;
+		if (generics == null) {
 			if (this.type instanceof Class) {
 				Class<?> typeClass = (Class<?>) this.type;
-				this.generics = forTypes(SerializableTypeWrapper.forTypeParameters(typeClass), this.variableResolver);
+				generics = forTypes(SerializableTypeWrapper.forTypeParameters(typeClass), this.variableResolver);
 			}
 			else if (this.type instanceof ParameterizedType) {
 				Type[] actualTypeArguments = ((ParameterizedType) this.type).getActualTypeArguments();
-				ResolvableType[] generics = new ResolvableType[actualTypeArguments.length];
+				generics = new ResolvableType[actualTypeArguments.length];
 				for (int i = 0; i < actualTypeArguments.length; i++) {
 					generics[i] = forType(actualTypeArguments[i], this.variableResolver);
 				}
-				this.generics = generics;
 			}
 			else {
-				this.generics = resolveType().getGenerics();
+				generics = resolveType().getGenerics();
 			}
+			this.generics = generics;
 		}
-		return this.generics;
+		return generics;
 	}
 
 	/**
@@ -748,7 +752,7 @@ public Class<?> resolveGeneric(int... indexes) {
 	 */
 	@Nullable
 	public Class<?> resolve() {
-		return (this.resolved != null ? this.resolved : null);
+		return this.resolved;
 	}
 
 	/**
@@ -1372,7 +1376,9 @@ static ResolvableType forType(@Nullable Type type, @Nullable VariableResolver va
 	 * @param variableResolver the variable resolver or {@code null}
 	 * @return a {@link ResolvableType} for the specified {@link Type} and {@link VariableResolver}
 	 */
-	static ResolvableType forType(@Nullable Type type, @Nullable TypeProvider typeProvider, @Nullable VariableResolver variableResolver) {
+	static ResolvableType forType(
+			@Nullable Type type, @Nullable TypeProvider typeProvider, @Nullable VariableResolver variableResolver) {
+
 		if (type == null && typeProvider != null) {
 			type = SerializableTypeWrapper.forTypeProvider(typeProvider);
 		}
@@ -1390,13 +1396,14 @@ static ResolvableType forType(@Nullable Type type, @Nullable TypeProvider typePr
 		cache.purgeUnreferencedEntries();
 
 		// Check the cache - we may have a ResolvableType which has been resolved before...
-		ResolvableType key = new ResolvableType(type, typeProvider, variableResolver);
-		ResolvableType resolvableType = cache.get(key);
-		if (resolvableType == null) {
-			resolvableType = new ResolvableType(type, typeProvider, variableResolver, key.hash);
-			cache.put(resolvableType, resolvableType);
-		}
-		return resolvableType;
+		ResolvableType resultType = new ResolvableType(type, typeProvider, variableResolver);
+		ResolvableType cachedType = cache.get(resultType);
+		if (cachedType == null) {
+			cachedType = new ResolvableType(type, typeProvider, variableResolver, resultType.hash);
+			cache.put(cachedType, cachedType);
+		}
+		resultType.resolved = cachedType.resolved;
+		return resultType;
 	}
 
 	/**

spring-core/src/test/java/org/springframework/core/ResolvableTypeTests.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.
@@ -176,11 +176,13 @@ public void forPrivateField() throws Exception {
 		ResolvableType type = ResolvableType.forField(field);
 		assertThat(type.getType(), equalTo(field.getGenericType()));
 		assertThat(type.resolve(), equalTo((Class) List.class));
+		assertThat(type.getSource(), sameInstance(field));
 
 		Field field2 = Fields.class.getDeclaredField("otherPrivateField");
 		ResolvableType type2 = ResolvableType.forField(field2);
 		assertThat(type2.getType(), equalTo(field2.getGenericType()));
 		assertThat(type2.resolve(), equalTo((Class) List.class));
+		assertThat(type2.getSource(), sameInstance(field2));
 
 		assertEquals(type, type2);
 		assertEquals(type.hashCode(), type2.hashCode());