Polish SpEL support

spring-expression/src/main/java/org/springframework/expression/spel/CompilablePropertyAccessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 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.
@@ -21,7 +21,7 @@ import org.springframework.asm.Opcodes;
 import org.springframework.expression.PropertyAccessor;
 
 /**
- * A compilable property accessor is able to generate bytecode that represents
+ * A compilable {@link PropertyAccessor} is able to generate bytecode that represents
  * the access operation, facilitating compilation to bytecode of expressions
  * that use the accessor.
  *
@@ -41,12 +41,13 @@ public interface CompilablePropertyAccessor extends PropertyAccessor, Opcodes {
 	Class<?> getPropertyType();
 
 	/**
-	 * Generate the bytecode the performs the access operation into the specified MethodVisitor
-	 * using context information from the codeflow where necessary.
+	 * Generate the bytecode the performs the access operation into the specified
+	 * {@link MethodVisitor} using context information from the {@link CodeFlow}
+	 * where necessary.
 	 * @param propertyName the name of the property
-	 * @param mv the Asm method visitor into which code should be generated
-	 * @param cf the current state of the expression compiler
+	 * @param methodVisitor the ASM method visitor into which code should be generated
+	 * @param codeFlow the current state of the expression compiler
 	 */
-	void generateCode(String propertyName, MethodVisitor mv, CodeFlow cf);
+	void generateCode(String propertyName, MethodVisitor methodVisitor, CodeFlow codeFlow);
 
 }

spring-expression/src/main/java/org/springframework/expression/spel/support/DataBindingMethodResolver.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.
@@ -27,7 +27,7 @@ import org.springframework.expression.MethodExecutor;
 import org.springframework.lang.Nullable;
 
 /**
- * A {@link org.springframework.expression.MethodResolver} variant for data binding
+ * An {@link org.springframework.expression.MethodResolver} variant for data binding
  * purposes, using reflection to access instance methods on a given target object.
  *
  * <p>This accessor does not resolve static methods and also no technical methods

spring-expression/src/main/java/org/springframework/expression/spel/support/DataBindingPropertyAccessor.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.
@@ -19,7 +19,7 @@ package org.springframework.expression.spel.support;
 import java.lang.reflect.Method;
 
 /**
- * A {@link org.springframework.expression.PropertyAccessor} variant for data binding
+ * An {@link org.springframework.expression.PropertyAccessor} variant for data binding
  * purposes, using reflection to access properties for reading and possibly writing.
  *
  * <p>A property can be referenced through a public getter method (when being read)

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 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.
@@ -503,14 +503,10 @@ public abstract class ReflectionHelper {
 	 * and the set that are being supplied at the point of invocation. If the kind
 	 * indicates that conversion is required for some of the arguments then the arguments
 	 * that require conversion are listed in the argsRequiringConversion array.
+	 *
+	 * @param kind the kind of match that was achieved
 	 */
-	static class ArgumentsMatchInfo {
-
-		private final ArgumentsMatchKind kind;
-
-		ArgumentsMatchInfo(ArgumentsMatchKind kind) {
-			this.kind = kind;
-		}
+	record ArgumentsMatchInfo(ArgumentsMatchKind kind) {
 
 		public boolean isExactMatch() {
 			return (this.kind == ArgumentsMatchKind.EXACT);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -33,7 +33,8 @@ import org.springframework.expression.TypeConverter;
 import org.springframework.lang.Nullable;
 
 /**
- * A constructor resolver that uses reflection to locate the constructor that should be invoked.
+ * A constructor resolver that uses reflection to locate the constructor that
+ * should be invoked.
  *
  * @author Andy Clement
  * @author Juergen Hoeller
@@ -42,12 +43,15 @@ import org.springframework.lang.Nullable;
 public class ReflectiveConstructorResolver implements ConstructorResolver {
 
 	/**
-	 * Locate a constructor on the type. There are three kinds of match that might occur:
+	 * Locate a constructor on the type.
+	 * <p>There are three kinds of matches that might occur:
 	 * <ol>
-	 * <li>An exact match where the types of the arguments match the types of the constructor
-	 * <li>An in-exact match where the types we are looking for are subtypes of those defined on the constructor
-	 * <li>A match where we are able to convert the arguments into those expected by the constructor, according to the
-	 * registered type converter.
+	 * <li>An exact match where the types of the arguments match the types of the
+	 * constructor.</li>
+	 * <li>An inexact match where the types we are looking for are subtypes of
+	 * those defined on the constructor.</li>
+	 * <li>A match where we are able to convert the arguments into those expected
+	 * by the constructor, according to the registered type converter.</li>
 	 * </ol>
 	 */
 	@Override

spring-expression/src/main/java/org/springframework/expression/spel/support/ReflectiveMethodExecutor.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.
@@ -87,12 +87,15 @@ public class ReflectiveMethodExecutor implements MethodExecutor {
 	}
 
 	/**
-	 * Find the first public class in the methods declaring class hierarchy that declares this method.
-	 * Sometimes the reflective method discovery logic finds a suitable method that can easily be
-	 * called via reflection but cannot be called from generated code when compiling the expression
-	 * because of visibility restrictions. For example if a non-public class overrides toString(),
-	 * this helper method will walk up the type hierarchy to find the first public type that declares
-	 * the method (if there is one!). For toString() it may walk as far as Object.
+	 * Find the first public class in the method's declaring class hierarchy that
+	 * declares this method.
+	 * <p>Sometimes the reflective method discovery logic finds a suitable method
+	 * that can easily be called via reflection but cannot be called from generated
+	 * code when compiling the expression because of visibility restrictions. For
+	 * example, if a non-public class overrides {@code toString()}, this helper
+	 * method will traverse up the type hierarchy to find the first public type that
+	 * declares the method (if there is one). For {@code toString()}, it may traverse
+	 * as far as Object.
 	 */
 	@Nullable
 	public Class<?> getPublicDeclaringClass() {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 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.
@@ -63,7 +63,7 @@ public class ReflectiveMethodResolver implements MethodResolver {
 
 
 	public ReflectiveMethodResolver() {
-		this.useDistance = true;
+		this(true);
 	}
 
 	/**
@@ -100,12 +100,15 @@ public class ReflectiveMethodResolver implements MethodResolver {
 	}
 
 	/**
-	 * Locate a method on a type. There are three kinds of match that might occur:
+	 * Locate a method on the type.
+	 * <p>There are three kinds of matches that might occur:
 	 * <ol>
-	 * <li>an exact match where the types of the arguments match the types of the constructor
-	 * <li>an in-exact match where the types we are looking for are subtypes of those defined on the constructor
-	 * <li>a match where we are able to convert the arguments into those expected by the constructor,
-	 * according to the registered type converter
+	 * <li>An exact match where the types of the arguments match the types of the
+	 * method.</li>
+	 * <li>An inexact match where the types we are looking for are subtypes of
+	 * those defined on the method.</li>
+	 * <li>A match where we are able to convert the arguments into those expected
+	 * by the method, according to the registered type converter.</li>
 	 * </ol>
 	 */
 	@Override

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

@@ -579,18 +579,7 @@ public class ReflectivePropertyAccessor implements PropertyAccessor {
 	 * Captures the member (method/field) to call reflectively to access a property value
 	 * and the type descriptor for the value returned by the reflective call.
 	 */
-	private static class InvokerPair {
-
-		final Member member;
-
-		final TypeDescriptor typeDescriptor;
-
-		public InvokerPair(Member member, TypeDescriptor typeDescriptor) {
-			this.member = member;
-			this.typeDescriptor = typeDescriptor;
-		}
-	}
-
+	private record InvokerPair(Member member, TypeDescriptor typeDescriptor) {}
 
 	private static final class PropertyCacheKey implements Comparable<PropertyCacheKey> {
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 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.
@@ -103,9 +103,9 @@ public final class SimpleEvaluationContext implements EvaluationContext {
 
 	private final TypeConverter typeConverter;
 
-	private final TypeComparator typeComparator = new StandardTypeComparator();
+	private final TypeComparator typeComparator = StandardTypeComparator.INSTANCE;
 
-	private final OperatorOverloader operatorOverloader = new StandardOperatorOverloader();
+	private final OperatorOverloader operatorOverloader = StandardOperatorOverloader.INSTANCE;
 
 	private final Map<String, Object> variables = new HashMap<>();
 
@@ -168,7 +168,7 @@ public final class SimpleEvaluationContext implements EvaluationContext {
 	/**
 	 * {@code SimpleEvaluationContext} does not support use of type references.
 	 * @return {@code TypeLocator} implementation that raises a
-	 * {@link SpelEvaluationException} with {@link SpelMessage#TYPE_NOT_FOUND}.
+	 * {@link SpelEvaluationException} with {@link SpelMessage#TYPE_NOT_FOUND}
 	 */
 	@Override
 	public TypeLocator getTypeLocator() {
@@ -315,7 +315,6 @@ public final class SimpleEvaluationContext implements EvaluationContext {
 			return this;
 		}
 
-
 		/**
 		 * Register a custom {@link ConversionService}.
 		 * <p>By default a {@link StandardTypeConverter} backed by a
@@ -327,6 +326,7 @@ public final class SimpleEvaluationContext implements EvaluationContext {
 			this.typeConverter = new StandardTypeConverter(conversionService);
 			return this;
 		}
+
 		/**
 		 * Register a custom {@link TypeConverter}.
 		 * <p>By default a {@link StandardTypeConverter} backed by a

spring-expression/src/test/java/org/springframework/expression/spel/support/StandardComponentsTests.java

@@ -16,8 +16,6 @@
 
 package org.springframework.expression.spel.support;
 
-import java.util.List;
-
 import org.junit.jupiter.api.Test;
 
 import org.springframework.core.convert.TypeDescriptor;
@@ -31,14 +29,14 @@ import org.springframework.expression.TypeLocator;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
-public class StandardComponentsTests {
+class StandardComponentsTests {
 
 	@Test
-	void testStandardEvaluationContext() {
+	void standardEvaluationContext() {
 		StandardEvaluationContext context = new StandardEvaluationContext();
 		assertThat(context.getTypeComparator()).isNotNull();
 
-		TypeComparator tc = new StandardTypeComparator();
+		TypeComparator tc = StandardTypeComparator.INSTANCE;
 		context.setTypeComparator(tc);
 		assertThat(context.getTypeComparator()).isEqualTo(tc);
 
@@ -48,28 +46,25 @@ public class StandardComponentsTests {
 	}
 
 	@Test
-	void testStandardOperatorOverloader() throws EvaluationException {
-		OperatorOverloader oo = new StandardOperatorOverloader();
-		assertThat(oo.overridesOperation(Operation.ADD, null, null)).isFalse();
-		assertThatExceptionOfType(EvaluationException.class).isThrownBy(() ->
-				oo.operate(Operation.ADD, 2, 3));
+	void standardOperatorOverloader() {
+		OperatorOverloader overloader = new StandardOperatorOverloader();
+		assertThat(overloader.overridesOperation(Operation.ADD, null, null)).isFalse();
+		assertThatExceptionOfType(EvaluationException.class)
+				.isThrownBy(() -> overloader.operate(Operation.ADD, 2, 3));
 	}
 
 	@Test
-	void testStandardTypeLocator() {
+	void standardTypeLocator() {
 		StandardTypeLocator tl = new StandardTypeLocator();
-		List<String> prefixes = tl.getImportPrefixes();
-		assertThat(prefixes).hasSize(1);
+		assertThat(tl.getImportPrefixes()).hasSize(1);
 		tl.registerImport("java.util");
-		prefixes = tl.getImportPrefixes();
-		assertThat(prefixes).hasSize(2);
+		assertThat(tl.getImportPrefixes()).hasSize(2);
 		tl.removeImport("java.util");
-		prefixes = tl.getImportPrefixes();
-		assertThat(prefixes).hasSize(1);
+		assertThat(tl.getImportPrefixes()).hasSize(1);
 	}
 
 	@Test
-	void testStandardTypeConverter() throws EvaluationException {
+	void standardTypeConverter() {
 		TypeConverter tc = new StandardTypeConverter();
 		tc.convertValue(3, TypeDescriptor.forObject(3), TypeDescriptor.valueOf(Double.class));
 	}