Expose implementation method for annotation introspection purposes

Closes gh-23210

Author: jhoeller

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectivePropertyAccessor.java

@@ -138,6 +138,7 @@ public boolean canRead(EvaluationContext context, @Nullable Object target, Strin
 			// The readerCache will only contain gettable properties (let's not worry about setters for now).
 			Property property = new Property(type, method, null);
 			TypeDescriptor typeDescriptor = new TypeDescriptor(property);
+			method = ClassUtils.getInterfaceMethodIfPossible(method);
 			this.readerCache.put(cacheKey, new InvokerPair(method, typeDescriptor));
 			this.typeDescriptorCache.put(cacheKey, typeDescriptor);
 			return true;
@@ -180,6 +181,7 @@ public TypedValue read(EvaluationContext context, @Nullable Object target, Strin
 					// The readerCache will only contain gettable properties (let's not worry about setters for now).
 					Property property = new Property(type, method, null);
 					TypeDescriptor typeDescriptor = new TypeDescriptor(property);
+					method = ClassUtils.getInterfaceMethodIfPossible(method);
 					invoker = new InvokerPair(method, typeDescriptor);
 					this.lastReadInvokerPair = invoker;
 					this.readerCache.put(cacheKey, invoker);
@@ -239,6 +241,7 @@ public boolean canWrite(EvaluationContext context, @Nullable Object target, Stri
 			// Treat it like a property
 			Property property = new Property(type, null, method);
 			TypeDescriptor typeDescriptor = new TypeDescriptor(property);
+			method = ClassUtils.getInterfaceMethodIfPossible(method);
 			this.writerCache.put(cacheKey, method);
 			this.typeDescriptorCache.put(cacheKey, typeDescriptor);
 			return true;
@@ -287,6 +290,7 @@ public void write(EvaluationContext context, @Nullable Object target, String nam
 			if (method == null) {
 				method = findSetterForProperty(name, type, target);
 				if (method != null) {
+					method = ClassUtils.getInterfaceMethodIfPossible(method);
 					cachedMember = method;
 					this.writerCache.put(cacheKey, cachedMember);
 				}
@@ -414,13 +418,24 @@ private Method findMethodForProperty(String[] methodSuffixes, String prefix, Cla
 						method.getParameterCount() == numberOfParams &&
 						(!mustBeStatic || Modifier.isStatic(method.getModifiers())) &&
 						(requiredReturnTypes.isEmpty() || requiredReturnTypes.contains(method.getReturnType()))) {
-					return ClassUtils.getInterfaceMethodIfPossible(method);
+					return method;
 				}
 			}
 		}
 		return null;
 	}
 
+	/**
+	 * Return class methods ordered with non-bridge methods appearing higher.
+	 */
+	private Method[] getSortedMethods(Class<?> clazz) {
+		return this.sortedMethodsCache.computeIfAbsent(clazz, key -> {
+			Method[] methods = key.getMethods();
+			Arrays.sort(methods, (o1, o2) -> (o1.isBridge() == o2.isBridge() ? 0 : (o1.isBridge() ? 1 : -1)));
+			return methods;
+		});
+	}
+
 	/**
 	 * Determine whether the given {@code Method} is a candidate for property access
 	 * on an instance of the given target class.
@@ -434,17 +449,6 @@ protected boolean isCandidateForProperty(Method method, Class<?> targetClass) {
 		return true;
 	}
 
-	/**
-	 * Return class methods ordered with non-bridge methods appearing higher.
-	 */
-	private Method[] getSortedMethods(Class<?> clazz) {
-		return this.sortedMethodsCache.computeIfAbsent(clazz, key -> {
-			Method[] methods = key.getMethods();
-			Arrays.sort(methods, (o1, o2) -> (o1.isBridge() == o2.isBridge() ? 0 : (o1.isBridge() ? 1 : -1)));
-			return methods;
-		});
-	}
-
 	/**
 	 * Return the method suffixes for a given property name. The default implementation
 	 * uses JavaBean conventions with additional support for properties of the form 'xY'
@@ -536,7 +540,9 @@ public PropertyAccessor createOptimalAccessor(EvaluationContext context, @Nullab
 			if (method == null) {
 				method = findGetterForProperty(name, clazz, target);
 				if (method != null) {
-					invocationTarget = new InvokerPair(method, new TypeDescriptor(new MethodParameter(method, -1)));
+					TypeDescriptor typeDescriptor = new TypeDescriptor(new MethodParameter(method, -1));
+					method = ClassUtils.getInterfaceMethodIfPossible(method);
+					invocationTarget = new InvokerPair(method, typeDescriptor);
 					ReflectionUtils.makeAccessible(method);
 					this.readerCache.put(cacheKey, invocationTarget);
 				}

spring-expression/src/test/java/org/springframework/expression/spel/SpelReproTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2019 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.
@@ -60,10 +60,18 @@
 import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.expression.spel.support.StandardTypeLocator;
 import org.springframework.expression.spel.testresources.le.div.mod.reserved.Reserver;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 /**
  * Reproduction tests cornering various reported SpEL issues.
@@ -1213,9 +1221,13 @@ public void SPR9486_floatPowerDouble() {
 	public void SPR9994_bridgeMethods() throws Exception {
 		ReflectivePropertyAccessor accessor = new ReflectivePropertyAccessor();
 		StandardEvaluationContext context = new StandardEvaluationContext();
-		Object target = new GenericImplementation();
+		GenericImplementation target = new GenericImplementation();
+		accessor.write(context, target, "property", "1");
+		assertEquals(1, target.value);
 		TypedValue value = accessor.read(context, target, "property");
+		assertEquals(1, value.getValue());
 		assertEquals(Integer.class, value.getTypeDescriptor().getType());
+		assertTrue(value.getTypeDescriptor().getAnnotations().length > 0);
 	}
 
 	@Test
@@ -1224,6 +1236,7 @@ public void SPR10162_onlyBridgeMethod() throws Exception {
 		StandardEvaluationContext context = new StandardEvaluationContext();
 		Object target = new OnlyBridgeMethod();
 		TypedValue value = accessor.read(context, target, "property");
+		assertNull(value.getValue());
 		assertEquals(Integer.class, value.getTypeDescriptor().getType());
 	}
 
@@ -1232,31 +1245,31 @@ public void SPR10091_simpleTestValueType() {
 		ExpressionParser parser = new SpelExpressionParser();
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext(new BooleanHolder());
 		Class<?> valueType = parser.parseExpression("simpleProperty").getValueType(evaluationContext);
-		assertNotNull(valueType);
+		assertEquals(Boolean.class, valueType);
 	}
 
 	@Test
 	public void SPR10091_simpleTestValue() {
 		ExpressionParser parser = new SpelExpressionParser();
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext(new BooleanHolder());
 		Object value = parser.parseExpression("simpleProperty").getValue(evaluationContext);
-		assertNotNull(value);
+		assertEquals(Boolean.class, value.getClass());
 	}
 
 	@Test
 	public void SPR10091_primitiveTestValueType() {
 		ExpressionParser parser = new SpelExpressionParser();
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext(new BooleanHolder());
 		Class<?> valueType = parser.parseExpression("primitiveProperty").getValueType(evaluationContext);
-		assertNotNull(valueType);
+		assertEquals(Boolean.class, valueType);
 	}
 
 	@Test
 	public void SPR10091_primitiveTestValue() {
 		ExpressionParser parser = new SpelExpressionParser();
 		StandardEvaluationContext evaluationContext = new StandardEvaluationContext(new BooleanHolder());
 		Object value = parser.parseExpression("primitiveProperty").getValue(evaluationContext);
-		assertNotNull(value);
+		assertEquals(Boolean.class, value.getClass());
 	}
 
 	@Test
@@ -2220,15 +2233,25 @@ public boolean isPrimitiveProperty() {
 
 	private interface GenericInterface<T extends Number> {
 
+		void setProperty(T value);
+
 		T getProperty();
 	}
 
 
 	private static class GenericImplementation implements GenericInterface<Integer> {
 
+		int value;
+
+		@Override
+		public void setProperty(Integer value) {
+			this.value = value;
+		}
+
 		@Override
+		@Nullable
 		public Integer getProperty() {
-			return null;
+			return this.value;
 		}
 	}