Polish and harmonize implementations of SpEL components in spring-context

Author: sbrannen

spring-context/src/main/java/org/springframework/context/expression/BeanExpressionContextAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -25,15 +25,20 @@
 import org.springframework.util.Assert;
 
 /**
- * EL property accessor that knows how to traverse the beans and contextual objects
- * of a Spring {@link org.springframework.beans.factory.config.BeanExpressionContext}.
+ * SpEL {@link PropertyAccessor} that knows how to access the beans and contextual
+ * objects of a Spring {@link BeanExpressionContext}.
  *
  * @author Juergen Hoeller
  * @author Andy Clement
  * @since 3.0
  */
 public class BeanExpressionContextAccessor implements PropertyAccessor {
 
+	@Override
+	public Class<?>[] getSpecificTargetClasses() {
+		return new Class<?>[] {BeanExpressionContext.class};
+	}
+
 	@Override
 	public boolean canRead(EvaluationContext context, @Nullable Object target, String name) throws AccessException {
 		return (target instanceof BeanExpressionContext bec && bec.containsObject(name));
@@ -57,9 +62,4 @@ public void write(EvaluationContext context, @Nullable Object target, String nam
 		throw new AccessException("Beans in a BeanFactory are read-only");
 	}
 
-	@Override
-	public Class<?>[] getSpecificTargetClasses() {
-		return new Class<?>[] {BeanExpressionContext.class};
-	}
-
 }

spring-context/src/main/java/org/springframework/context/expression/BeanFactoryAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -25,8 +25,8 @@
 import org.springframework.util.Assert;
 
 /**
- * EL property accessor that knows how to traverse the beans of a
- * Spring {@link org.springframework.beans.factory.BeanFactory}.
+ * SpEL {@link PropertyAccessor} that knows how to access the beans of a
+ * Spring {@link BeanFactory}.
  *
  * @author Juergen Hoeller
  * @author Andy Clement

spring-context/src/main/java/org/springframework/context/expression/BeanFactoryResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -24,8 +24,7 @@
 import org.springframework.util.Assert;
 
 /**
- * EL bean resolver that operates against a Spring
- * {@link org.springframework.beans.factory.BeanFactory}.
+ * SpEL {@link BeanResolver} that operates against a Spring {@link BeanFactory}.
  *
  * @author Juergen Hoeller
  * @since 3.0.4
@@ -36,8 +35,8 @@ public class BeanFactoryResolver implements BeanResolver {
 
 
 	/**
-	 * Create a new {@link BeanFactoryResolver} for the given factory.
-	 * @param beanFactory the {@link BeanFactory} to resolve bean names against
+	 * Create a new {@code BeanFactoryResolver} for the given factory.
+	 * @param beanFactory the {@code BeanFactory} to resolve bean names against
 	 */
 	public BeanFactoryResolver(BeanFactory beanFactory) {
 		Assert.notNull(beanFactory, "BeanFactory must not be null");

spring-context/src/main/java/org/springframework/context/expression/EnvironmentAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -25,7 +25,7 @@
 import org.springframework.util.Assert;
 
 /**
- * Read-only EL property accessor that knows how to retrieve keys
+ * Read-only SpEL {@link PropertyAccessor} that knows how to retrieve properties
  * of a Spring {@link Environment} instance.
  *
  * @author Chris Beams
@@ -38,18 +38,14 @@ public Class<?>[] getSpecificTargetClasses() {
 		return new Class<?>[] {Environment.class};
 	}
 
-	/**
-	 * Can read any {@link Environment}, thus always returns true.
-	 * @return true
-	 */
 	@Override
 	public boolean canRead(EvaluationContext context, @Nullable Object target, String name) throws AccessException {
-		return true;
+		return (target instanceof Environment);
 	}
 
 	/**
-	 * Access the given target object by resolving the given property name against the given target
-	 * environment.
+	 * Access the given target object by resolving the given property name against
+	 * the given target environment.
 	 */
 	@Override
 	public TypedValue read(EvaluationContext context, @Nullable Object target, String name) throws AccessException {
@@ -65,12 +61,11 @@ public boolean canWrite(EvaluationContext context, @Nullable Object target, Stri
 		return false;
 	}
 
-	/**
-	 * Read-only: no-op.
-	 */
 	@Override
 	public void write(EvaluationContext context, @Nullable Object target, String name, @Nullable Object newValue)
 			throws AccessException {
+
+		throw new AccessException("The Environment is read-only");
 	}
 
 }

spring-context/src/main/java/org/springframework/context/expression/MapAccessor.java

@@ -21,15 +21,16 @@
 import org.springframework.asm.MethodVisitor;
 import org.springframework.expression.AccessException;
 import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.PropertyAccessor;
 import org.springframework.expression.TypedValue;
 import org.springframework.expression.spel.CodeFlow;
 import org.springframework.expression.spel.CompilablePropertyAccessor;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
- * EL property accessor that knows how to traverse the keys
- * of a standard {@link java.util.Map}.
+ * SpEL {@link PropertyAccessor} that knows how to access the keys of a standard
+ * {@link java.util.Map}.
  *
  * @author Juergen Hoeller
  * @author Andy Clement
@@ -39,8 +40,9 @@ public class MapAccessor implements CompilablePropertyAccessor {
 
 	private final boolean allowWrite;
 
+
 	/**
-	 * Create a new map accessor for reading as well as writing.
+	 * Create a new {@code MapAccessor} for reading as well as writing.
 	 * @since 6.2
 	 * @see #MapAccessor(boolean)
 	 */
@@ -49,7 +51,7 @@ public MapAccessor() {
 	}
 
 	/**
-	 * Create a new map accessor for reading and possibly also writing.
+	 * Create a new {@code MapAccessor} for reading and possibly also writing.
 	 * @param allowWrite whether to allow write operations on a target instance
 	 * @since 6.2
 	 * @see #canWrite
@@ -58,6 +60,7 @@ public MapAccessor(boolean allowWrite) {
 		this.allowWrite = allowWrite;
 	}
 
+
 	@Override
 	public Class<?>[] getSpecificTargetClasses() {
 		return new Class<?>[] {Map.class};

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

@@ -36,8 +36,9 @@ public class CompilableMapAccessor implements CompilablePropertyAccessor {
 
 	private final boolean allowWrite;
 
+
 	/**
-	 * Create a new map accessor for reading as well as writing.
+	 * Create a new {@code CompilableMapAccessor} for reading as well as writing.
 	 * @since 6.2
 	 * @see #CompilableMapAccessor(boolean)
 	 */
@@ -46,7 +47,7 @@ public CompilableMapAccessor() {
 	}
 
 	/**
-	 * Create a new map accessor for reading and possibly also writing.
+	 * Create a new {@code CompilableMapAccessor} for reading and possibly also writing.
 	 * @param allowWrite whether to allow write operations on a target instance
 	 * @since 6.2
 	 * @see #canWrite
@@ -55,6 +56,7 @@ public CompilableMapAccessor(boolean allowWrite) {
 		this.allowWrite = allowWrite;
 	}
 
+
 	@Override
 	public Class<?>[] getSpecificTargetClasses() {
 		return new Class<?>[] {Map.class};