Hacking

See spring-projectsgh-31617

spring-context/src/main/java/org/springframework/cache/interceptor/CacheAspectSupport.java

@@ -47,11 +47,13 @@
 import org.springframework.cache.Cache;
 import org.springframework.cache.CacheManager;
 import org.springframework.context.expression.AnnotatedElementKey;
+import org.springframework.context.expression.BeanFactoryResolver;
 import org.springframework.core.BridgeMethodResolver;
 import org.springframework.core.KotlinDetector;
 import org.springframework.core.ReactiveAdapter;
 import org.springframework.core.ReactiveAdapterRegistry;
 import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -99,7 +101,10 @@ public abstract class CacheAspectSupport extends AbstractCacheInvoker
 
 	private final Map<CacheOperationCacheKey, CacheOperationMetadata> metadataCache = new ConcurrentHashMap<>(1024);
 
-	private final CacheOperationExpressionEvaluator evaluator = new CacheOperationExpressionEvaluator();
+	private final StandardEvaluationContext originalEvaluationContext = new StandardEvaluationContext();
+
+	private final CacheOperationExpressionEvaluator evaluator = new CacheOperationExpressionEvaluator(
+			new CacheEvaluationContextFactory(this.originalEvaluationContext));
 
 	@Nullable
 	private final ReactiveCachingHandler reactiveCachingHandler;
@@ -222,6 +227,7 @@ public void setCacheManager(CacheManager cacheManager) {
 	@Override
 	public void setBeanFactory(BeanFactory beanFactory) {
 		this.beanFactory = beanFactory;
+		this.originalEvaluationContext.setBeanResolver(new BeanFactoryResolver(beanFactory));
 	}
 
 
@@ -852,7 +858,7 @@ protected Object generateKey(@Nullable Object result) {
 
 		private EvaluationContext createEvaluationContext(@Nullable Object result) {
 			return evaluator.createEvaluationContext(this.caches, this.metadata.method, this.args,
-					this.target, this.metadata.targetClass, this.metadata.targetMethod, result, beanFactory);
+					this.target, this.metadata.targetClass, this.metadata.targetMethod, result);
 		}
 
 		protected Collection<? extends Cache> getCaches() {

spring-context/src/main/java/org/springframework/cache/interceptor/CacheEvaluationContextFactory.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2002-2023 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cache.interceptor;
+
+import java.lang.reflect.Method;
+import java.util.function.Supplier;
+
+import org.springframework.core.DefaultParameterNameDiscoverer;
+import org.springframework.core.ParameterNameDiscoverer;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+import org.springframework.lang.Nullable;
+import org.springframework.util.function.SingletonSupplier;
+
+/**
+ * A factory for {@link CacheEvaluationContext} that makes sure that internal
+ * delegates are reused.
+ *
+ * @author Stephane Nicoll
+ * @since 6.1.1
+ */
+class CacheEvaluationContextFactory {
+
+	private final StandardEvaluationContext originalContext;
+
+	@Nullable
+	private Supplier<ParameterNameDiscoverer> parameterNameDiscoverer;
+
+	CacheEvaluationContextFactory(StandardEvaluationContext originalContext) {
+		this.originalContext = originalContext;
+	}
+
+	public void setParameterNameDiscoverer(Supplier<ParameterNameDiscoverer> parameterNameDiscoverer) {
+		this.parameterNameDiscoverer = parameterNameDiscoverer;
+	}
+
+	public ParameterNameDiscoverer getParameterNameDiscoverer() {
+		if (this.parameterNameDiscoverer == null) {
+			this.parameterNameDiscoverer = SingletonSupplier.of(new DefaultParameterNameDiscoverer());
+		}
+		return this.parameterNameDiscoverer.get();
+	}
+
+	/**
+	 * Creates a {@link CacheEvaluationContext} for the specified operation.
+	 * @param rootObject the {@code root} object to use for the context
+	 * @param targetMethod the target cache {@link Method}
+	 * @param args the arguments of the method invocation
+	 * @return a context suitable for this cache operation
+	 */
+	public CacheEvaluationContext forOperation(CacheExpressionRootObject rootObject,
+			Method targetMethod, Object[] args) {
+
+		CacheEvaluationContext evaluationContext = new CacheEvaluationContext(
+				rootObject, targetMethod, args, getParameterNameDiscoverer());
+		this.originalContext.applyDelegatesTo(evaluationContext);
+		return evaluationContext;
+	}
+
+}

spring-context/src/main/java/org/springframework/cache/interceptor/CacheOperationExpressionEvaluator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -21,10 +21,8 @@
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 
-import org.springframework.beans.factory.BeanFactory;
 import org.springframework.cache.Cache;
 import org.springframework.context.expression.AnnotatedElementKey;
-import org.springframework.context.expression.BeanFactoryResolver;
 import org.springframework.context.expression.CachedExpressionEvaluator;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.Expression;
@@ -67,6 +65,13 @@ class CacheOperationExpressionEvaluator extends CachedExpressionEvaluator {
 
 	private final Map<ExpressionKey, Expression> unlessCache = new ConcurrentHashMap<>(64);
 
+	private final CacheEvaluationContextFactory evaluationContextFactory;
+
+	public CacheOperationExpressionEvaluator(CacheEvaluationContextFactory evaluationContextFactory) {
+		super();
+		this.evaluationContextFactory = evaluationContextFactory;
+		this.evaluationContextFactory.setParameterNameDiscoverer(this::getParameterNameDiscoverer);
+	}
 
 	/**
 	 * Create an {@link EvaluationContext}.
@@ -81,21 +86,18 @@ class CacheOperationExpressionEvaluator extends CachedExpressionEvaluator {
 	 */
 	public EvaluationContext createEvaluationContext(Collection<? extends Cache> caches,
 			Method method, Object[] args, Object target, Class<?> targetClass, Method targetMethod,
-			@Nullable Object result, @Nullable BeanFactory beanFactory) {
+			@Nullable Object result) {
 
 		CacheExpressionRootObject rootObject = new CacheExpressionRootObject(
 				caches, method, args, target, targetClass);
-		CacheEvaluationContext evaluationContext = new CacheEvaluationContext(
-				rootObject, targetMethod, args, getParameterNameDiscoverer());
+		CacheEvaluationContext evaluationContext = this.evaluationContextFactory
+				.forOperation(rootObject, targetMethod, args);
 		if (result == RESULT_UNAVAILABLE) {
 			evaluationContext.addUnavailableVariable(RESULT_VARIABLE);
 		}
 		else if (result != NO_RESULT) {
 			evaluationContext.setVariable(RESULT_VARIABLE, result);
 		}
-		if (beanFactory != null) {
-			evaluationContext.setBeanResolver(new BeanFactoryResolver(beanFactory));
-		}
 		return evaluationContext;
 	}
 

spring-context/src/test/java/org/springframework/cache/interceptor/ExpressionEvaluatorTests.java

@@ -31,9 +31,12 @@
 import org.springframework.cache.annotation.Caching;
 import org.springframework.cache.concurrent.ConcurrentMapCache;
 import org.springframework.context.expression.AnnotatedElementKey;
+import org.springframework.context.expression.BeanFactoryResolver;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ReflectionUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -47,7 +50,10 @@
  */
 public class ExpressionEvaluatorTests {
 
-	private final CacheOperationExpressionEvaluator eval = new CacheOperationExpressionEvaluator();
+	private final StandardEvaluationContext originalEvaluationContext = new StandardEvaluationContext();
+
+	private final CacheOperationExpressionEvaluator eval = new CacheOperationExpressionEvaluator(
+			new CacheEvaluationContextFactory(this.originalEvaluationContext));
 
 	private final AnnotationCacheOperationSource source = new AnnotationCacheOperationSource();
 
@@ -82,7 +88,7 @@ public void testMultipleCachingEval() {
 		Collection<ConcurrentMapCache> caches = Collections.singleton(new ConcurrentMapCache("test"));
 
 		EvaluationContext evalCtx = this.eval.createEvaluationContext(caches, method, args,
-				target, target.getClass(), method, CacheOperationExpressionEvaluator.NO_RESULT, null);
+				target, target.getClass(), method, CacheOperationExpressionEvaluator.NO_RESULT);
 		Collection<CacheOperation> ops = getOps("multipleCaching");
 
 		Iterator<CacheOperation> it = ops.iterator();
@@ -140,14 +146,17 @@ private EvaluationContext createEvaluationContext(Object result) {
 		return createEvaluationContext(result, null);
 	}
 
-	private EvaluationContext createEvaluationContext(Object result, BeanFactory beanFactory) {
+	private EvaluationContext createEvaluationContext(Object result, @Nullable BeanFactory beanFactory) {
+		if (beanFactory != null) {
+			this.originalEvaluationContext.setBeanResolver(new BeanFactoryResolver(beanFactory));
+		}
 		AnnotatedClass target = new AnnotatedClass();
 		Method method = ReflectionUtils.findMethod(
 				AnnotatedClass.class, "multipleCaching", Object.class, Object.class);
 		Object[] args = new Object[] {new Object(), new Object()};
 		Collection<ConcurrentMapCache> caches = Collections.singleton(new ConcurrentMapCache("test"));
 		return this.eval.createEvaluationContext(
-				caches, method, args, target, target.getClass(), method, result, beanFactory);
+				caches, method, args, target, target.getClass(), method, result);
 	}
 
 

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

@@ -55,6 +55,7 @@
  * @author Andy Clement
  * @author Juergen Hoeller
  * @author Sam Brannen
+ * @author Stephane Nicoll
  * @since 3.0
  * @see SimpleEvaluationContext
  * @see ReflectivePropertyAccessor
@@ -90,9 +91,9 @@ public class StandardEvaluationContext implements EvaluationContext {
 	@Nullable
 	private TypeConverter typeConverter;
 
-	private TypeComparator typeComparator = new StandardTypeComparator();
+	private TypeComparator typeComparator = StandardTypeComparator.INSTANCE;
 
-	private OperatorOverloader operatorOverloader = new StandardOperatorOverloader();
+	private OperatorOverloader operatorOverloader = StandardOperatorOverloader.INSTANCE;
 
 	private final Map<String, Object> variables = new ConcurrentHashMap<>();
 
@@ -329,6 +330,29 @@ public void registerMethodFilter(Class<?> type, MethodFilter filter) throws Ille
 		resolver.registerMethodFilter(type, filter);
 	}
 
+	/**
+	 * Apply the internal delegates of this instance to the specified
+	 * {@code evaluationContext}. Useful when a new context needs to be created per
+	 * operation, and delegates can and should be reused. Do not modify the
+	 * {@linkplain #setRootObject(Object) root object} or any registered
+	 * {@linkplain #setVariables(Map) variables}.
+	 * @param evaluationContext the evaluation context to update
+	 * @since 6.1.1
+	 */
+	public void applyDelegatesTo(StandardEvaluationContext evaluationContext) {
+		// Triggers initialization for default delegates
+		evaluationContext.setConstructorResolvers(this.getConstructorResolvers());
+		evaluationContext.setMethodResolvers(this.getMethodResolvers());
+		evaluationContext.setPropertyAccessors(this.getPropertyAccessors());
+		evaluationContext.setTypeLocator(this.getTypeLocator());
+		evaluationContext.setTypeConverter(this.getTypeConverter());
+
+		evaluationContext.beanResolver = this.beanResolver;
+		evaluationContext.operatorOverloader = this.operatorOverloader;
+		evaluationContext.reflectiveMethodResolver = this.reflectiveMethodResolver;
+		evaluationContext.typeComparator = this.typeComparator;
+	}
+
 
 	private List<PropertyAccessor> initPropertyAccessors() {
 		List<PropertyAccessor> accessors = this.propertyAccessors;

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -29,6 +29,8 @@
  */
 public class StandardOperatorOverloader implements OperatorOverloader {
 
+	static final StandardOperatorOverloader INSTANCE = new StandardOperatorOverloader();
+
 	@Override
 	public boolean overridesOperation(Operation operation, @Nullable Object leftOperand, @Nullable Object rightOperand)
 			throws EvaluationException {

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

@@ -37,6 +37,8 @@
  */
 public class StandardTypeComparator implements TypeComparator {
 
+	static final StandardTypeComparator INSTANCE = new StandardTypeComparator();
+
 	@Override
 	public boolean canCompare(@Nullable Object left, @Nullable Object right) {
 		if (left == null || right == null) {