Apply "instanceof pattern matching" in spring-expression

This commit also applies additional clean-up tasks such as the following.

- final fields

This commit also makes use of java.lang.String.repeat(int) in OptMultiply.

This has only been applied to `src/main/java`.

spring-expression/src/main/java/org/springframework/expression/TypedValue.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -85,10 +85,9 @@ public boolean equals(@Nullable Object other) {
 		if (this == other) {
 			return true;
 		}
-		if (!(other instanceof TypedValue)) {
+		if (!(other instanceof TypedValue otherTv)) {
 			return false;
 		}
-		TypedValue otherTv = (TypedValue) other;
 		// Avoid TypeDescriptor initialization if not necessary
 		return (ObjectUtils.nullSafeEquals(this.value, otherTv.value) &&
 				((this.typeDescriptor == null && otherTv.typeDescriptor == null) ||

spring-expression/src/main/java/org/springframework/expression/spel/ast/ConstructorReference.java

@@ -136,8 +136,8 @@ private TypedValue createNewInstance(ExpressionState state) throws EvaluationExc
 				if (ex.getCause() instanceof InvocationTargetException) {
 					// User exception was the root cause - exit now
 					Throwable rootCause = ex.getCause().getCause();
-					if (rootCause instanceof RuntimeException) {
-						throw (RuntimeException) rootCause;
+					if (rootCause instanceof RuntimeException runtimeException) {
+						throw runtimeException;
 					}
 					else {
 						String typeName = (String) this.children[0].getValueInternal(state).getValue();
@@ -158,9 +158,9 @@ private TypedValue createNewInstance(ExpressionState state) throws EvaluationExc
 		executorToUse = findExecutorForConstructor(typeName, argumentTypes, state);
 		try {
 			this.cachedExecutor = executorToUse;
-			if (executorToUse instanceof ReflectiveConstructorExecutor) {
+			if (executorToUse instanceof ReflectiveConstructorExecutor reflectiveConstructorExecutor) {
 				this.exitTypeDescriptor = CodeFlow.toDescriptor(
-						((ReflectiveConstructorExecutor) executorToUse).getConstructor().getDeclaringClass());
+						reflectiveConstructorExecutor.getConstructor().getDeclaringClass());
 
 			}
 			return executorToUse.execute(state.getEvaluationContext(), arguments);
@@ -228,14 +228,13 @@ public String toStringAST() {
 	private TypedValue createArray(ExpressionState state) throws EvaluationException {
 		// First child gives us the array type which will either be a primitive or reference type
 		Object intendedArrayType = getChild(0).getValue(state);
-		if (!(intendedArrayType instanceof String)) {
+		if (!(intendedArrayType instanceof String type)) {
 			throw new SpelEvaluationException(getChild(0).getStartPosition(),
 					SpelMessage.TYPE_NAME_EXPECTED_FOR_ARRAY_CONSTRUCTION,
 					FormatHelper.formatClassNameForMessage(
 							intendedArrayType != null ? intendedArrayType.getClass() : null));
 		}
 
-		String type = (String) intendedArrayType;
 		Class<?> componentType;
 		TypeCode arrayTypeCode = TypeCode.forName(type);
 		if (arrayTypeCode == TypeCode.OBJECT) {

spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -50,6 +50,7 @@
  * @author Andy Clement
  * @author Phillip Webb
  * @author Stephane Nicoll
+ * @author Sam Brannen
  * @since 3.0
  */
 // TODO support multidimensional arrays
@@ -121,8 +122,7 @@ protected ValueRef getValueRef(ExpressionState state) throws EvaluationException
 		Object index;
 
 		// This first part of the if clause prevents a 'double dereference' of the property (SPR-5847)
-		if (target instanceof Map && (this.children[0] instanceof PropertyOrFieldReference)) {
-			PropertyOrFieldReference reference = (PropertyOrFieldReference) this.children[0];
+		if (target instanceof Map && (this.children[0] instanceof PropertyOrFieldReference reference)) {
 			index = reference.getName();
 			indexValue = new TypedValue(index);
 		}
@@ -148,13 +148,13 @@ protected ValueRef getValueRef(ExpressionState state) throws EvaluationException
 		Assert.state(targetDescriptor != null, "No type descriptor");
 
 		// Indexing into a Map
-		if (target instanceof Map) {
+		if (target instanceof Map<?, ?> map) {
 			Object key = index;
 			if (targetDescriptor.getMapKeyTypeDescriptor() != null) {
 				key = state.convertValue(key, targetDescriptor.getMapKeyTypeDescriptor());
 			}
 			this.indexedType = IndexedType.MAP;
-			return new MapIndexingValueRef(state.getTypeConverter(), (Map<?, ?>) target, key, targetDescriptor);
+			return new MapIndexingValueRef(state.getTypeConverter(), map, key, targetDescriptor);
 		}
 
 		// If the object is something that looks indexable by an integer,
@@ -275,8 +275,7 @@ else if (this.indexedType == IndexedType.MAP) {
 			mv.visitTypeInsn(CHECKCAST, "java/util/Map");
 			// Special case when the key is an unquoted string literal that will be parsed as
 			// a property/field reference
-			if ((this.children[0] instanceof PropertyOrFieldReference)) {
-				PropertyOrFieldReference reference = (PropertyOrFieldReference) this.children[0];
+			if ((this.children[0] instanceof PropertyOrFieldReference reference)) {
 				String mapKeyName = reference.getName();
 				mv.visitLdcInsn(mapKeyName);
 			}
@@ -306,9 +305,9 @@ else if (this.indexedType == IndexedType.OBJECT) {
 				}
 			}
 
-			if (member instanceof Method) {
+			if (member instanceof Method method) {
 				mv.visitMethodInsn((isStatic? INVOKESTATIC : INVOKEVIRTUAL), classDesc, member.getName(),
-						CodeFlow.createSignatureDescriptor((Method) member), false);
+						CodeFlow.createSignatureDescriptor(method), false);
 			}
 			else {
 				mv.visitFieldInsn((isStatic ? GETSTATIC : GETFIELD), classDesc, member.getName(),
@@ -572,19 +571,17 @@ public TypedValue getValue() {
 						targetObjectRuntimeClass, this.evaluationContext.getPropertyAccessors());
 				for (PropertyAccessor accessor : accessorsToTry) {
 					if (accessor.canRead(this.evaluationContext, this.targetObject, this.name)) {
-						if (accessor instanceof ReflectivePropertyAccessor) {
-							accessor = ((ReflectivePropertyAccessor) accessor).createOptimalAccessor(
+						if (accessor instanceof ReflectivePropertyAccessor reflectivePropertyAccessor) {
+							accessor = reflectivePropertyAccessor.createOptimalAccessor(
 									this.evaluationContext, this.targetObject, this.name);
 						}
 						Indexer.this.cachedReadAccessor = accessor;
 						Indexer.this.cachedReadName = this.name;
 						Indexer.this.cachedReadTargetType = targetObjectRuntimeClass;
-						if (accessor instanceof ReflectivePropertyAccessor.OptimalPropertyAccessor) {
-							ReflectivePropertyAccessor.OptimalPropertyAccessor optimalAccessor =
-									(ReflectivePropertyAccessor.OptimalPropertyAccessor) accessor;
+						if (accessor instanceof ReflectivePropertyAccessor.OptimalPropertyAccessor optimalAccessor) {
 							Member member = optimalAccessor.member;
-							Indexer.this.exitTypeDescriptor = CodeFlow.toDescriptor(member instanceof Method ?
-									((Method) member).getReturnType() : ((Field) member).getType());
+							Indexer.this.exitTypeDescriptor = CodeFlow.toDescriptor(member instanceof Method method ?
+									method.getReturnType() : ((Field) member).getType());
 						}
 						return accessor.read(this.evaluationContext, this.targetObject, this.name);
 					}
@@ -665,8 +662,8 @@ public CollectionIndexingValueRef(Collection collection, int index, TypeDescript
 		@Override
 		public TypedValue getValue() {
 			growCollectionIfNecessary();
-			if (this.collection instanceof List) {
-				Object o = ((List) this.collection).get(this.index);
+			if (this.collection instanceof List list) {
+				Object o = list.get(this.index);
 				exitTypeDescriptor = CodeFlow.toDescriptor(Object.class);
 				return new TypedValue(o, this.collectionEntryDescriptor.elementTypeDescriptor(o));
 			}
@@ -683,8 +680,7 @@ public TypedValue getValue() {
 		@Override
 		public void setValue(@Nullable Object newValue) {
 			growCollectionIfNecessary();
-			if (this.collection instanceof List) {
-				List list = (List) this.collection;
+			if (this.collection instanceof List list) {
 				if (this.collectionEntryDescriptor.getElementTypeDescriptor() != null) {
 					newValue = this.typeConverter.convertValue(newValue, TypeDescriptor.forObject(newValue),
 							this.collectionEntryDescriptor.getElementTypeDescriptor());

spring-expression/src/main/java/org/springframework/expression/spel/ast/InlineList.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -34,6 +34,7 @@
  * Represent a list in an expression, e.g. '{1,2,3}'
  *
  * @author Andy Clement
+ * @author Sam Brannen
  * @since 3.0.4
  */
 public class InlineList extends SpelNodeImpl {
@@ -59,8 +60,7 @@ private void checkIfConstant() {
 		for (int c = 0, max = getChildCount(); c < max; c++) {
 			SpelNode child = getChild(c);
 			if (!(child instanceof Literal)) {
-				if (child instanceof InlineList) {
-					InlineList inlineList = (InlineList) child;
+				if (child instanceof InlineList inlineList) {
 					if (!inlineList.isConstant()) {
 						isConstant = false;
 					}
@@ -75,11 +75,11 @@ private void checkIfConstant() {
 			int childcount = getChildCount();
 			for (int c = 0; c < childcount; c++) {
 				SpelNode child = getChild(c);
-				if ((child instanceof Literal)) {
-					constantList.add(((Literal) child).getLiteralValue().getValue());
+				if (child instanceof Literal literal) {
+					constantList.add(literal.getLiteralValue().getValue());
 				}
-				else if (child instanceof InlineList) {
-					constantList.add(((InlineList) child).getConstantValue());
+				else if (child instanceof InlineList inlineList) {
+					constantList.add(inlineList.getConstantValue());
 				}
 			}
 			this.constant = new TypedValue(Collections.unmodifiableList(constantList));
@@ -164,8 +164,8 @@ void generateClinitCode(String clazzname, String constantFieldName, MethodVisito
 			// The children might be further lists if they are not constants. In this
 			// situation do not call back into generateCode() because it will register another clinit adder.
 			// Instead, directly build the list here:
-			if (this.children[c] instanceof InlineList) {
-				((InlineList)this.children[c]).generateClinitCode(clazzname, constantFieldName, mv, codeflow, true);
+			if (this.children[c] instanceof InlineList inlineList) {
+				inlineList.generateClinitCode(clazzname, constantFieldName, mv, codeflow, true);
 			}
 			else {
 				this.children[c].generateCode(mv, codeflow);

spring-expression/src/main/java/org/springframework/expression/spel/ast/InlineMap.java

@@ -31,6 +31,7 @@
  * Represent a map in an expression, e.g. '{name:'foo',age:12}'
  *
  * @author Andy Clement
+ * @author Sam Brannen
  * @since 4.1
  */
 public class InlineMap extends SpelNodeImpl {
@@ -56,15 +57,13 @@ private void checkIfConstant() {
 		for (int c = 0, max = getChildCount(); c < max; c++) {
 			SpelNode child = getChild(c);
 			if (!(child instanceof Literal)) {
-				if (child instanceof InlineList) {
-					InlineList inlineList = (InlineList) child;
+				if (child instanceof InlineList inlineList) {
 					if (!inlineList.isConstant()) {
 						isConstant = false;
 						break;
 					}
 				}
-				else if (child instanceof InlineMap) {
-					InlineMap inlineMap = (InlineMap) child;
+				else if (child instanceof InlineMap inlineMap) {
 					if (!inlineMap.isConstant()) {
 						isConstant = false;
 						break;
@@ -84,23 +83,23 @@ else if (!(c % 2 == 0 && child instanceof PropertyOrFieldReference)) {
 				SpelNode valueChild = getChild(c);
 				Object key = null;
 				Object value = null;
-				if (keyChild instanceof Literal) {
-					key = ((Literal) keyChild).getLiteralValue().getValue();
+				if (keyChild instanceof Literal literal) {
+					key = literal.getLiteralValue().getValue();
 				}
-				else if (keyChild instanceof PropertyOrFieldReference) {
-					key = ((PropertyOrFieldReference) keyChild).getName();
+				else if (keyChild instanceof PropertyOrFieldReference propertyOrFieldReference) {
+					key = propertyOrFieldReference.getName();
 				}
 				else {
 					return;
 				}
-				if (valueChild instanceof Literal) {
-					value = ((Literal) valueChild).getLiteralValue().getValue();
+				if (valueChild instanceof Literal literal) {
+					value = literal.getLiteralValue().getValue();
 				}
-				else if (valueChild instanceof InlineList) {
-					value = ((InlineList) valueChild).getConstantValue();
+				else if (valueChild instanceof InlineList inlineList) {
+					value = inlineList.getConstantValue();
 				}
-				else if (valueChild instanceof InlineMap) {
-					value = ((InlineMap) valueChild).getConstantValue();
+				else if (valueChild instanceof InlineMap inlineMap) {
+					value = inlineMap.getConstantValue();
 				}
 				constantMap.put(key, value);
 			}
@@ -120,8 +119,7 @@ public TypedValue getValueInternal(ExpressionState expressionState) throws Evalu
 				// TODO allow for key being PropertyOrFieldReference like Indexer on maps
 				SpelNode keyChild = getChild(c++);
 				Object key = null;
-				if (keyChild instanceof PropertyOrFieldReference) {
-					PropertyOrFieldReference reference = (PropertyOrFieldReference) keyChild;
+				if (keyChild instanceof PropertyOrFieldReference reference) {
 					key = reference.getName();
 				}
 				else {

spring-expression/src/main/java/org/springframework/expression/spel/ast/OpDec.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -34,6 +34,7 @@
  * @author Andy Clement
  * @author Juergen Hoeller
  * @author Giovanni Dall'Oglio Risso
+ * @author Sam Brannen
  * @since 3.2
  */
 public class OpDec extends Operator {
@@ -60,19 +61,18 @@ public TypedValue getValueInternal(ExpressionState state) throws EvaluationExcep
 		TypedValue returnValue = operandTypedValue;
 		TypedValue newValue = null;
 
-		if (operandValue instanceof Number) {
-			Number op1 = (Number) operandValue;
-			if (op1 instanceof BigDecimal) {
-				newValue = new TypedValue(((BigDecimal) op1).subtract(BigDecimal.ONE), operandTypedValue.getTypeDescriptor());
+		if (operandValue instanceof Number op1) {
+			if (op1 instanceof BigDecimal bigDecimal) {
+				newValue = new TypedValue(bigDecimal.subtract(BigDecimal.ONE), operandTypedValue.getTypeDescriptor());
 			}
 			else if (op1 instanceof Double) {
 				newValue = new TypedValue(op1.doubleValue() - 1.0d, operandTypedValue.getTypeDescriptor());
 			}
 			else if (op1 instanceof Float) {
 				newValue = new TypedValue(op1.floatValue() - 1.0f, operandTypedValue.getTypeDescriptor());
 			}
-			else if (op1 instanceof BigInteger) {
-				newValue = new TypedValue(((BigInteger) op1).subtract(BigInteger.ONE), operandTypedValue.getTypeDescriptor());
+			else if (op1 instanceof BigInteger bigInteger) {
+				newValue = new TypedValue(bigInteger.subtract(BigInteger.ONE), operandTypedValue.getTypeDescriptor());
 			}
 			else if (op1 instanceof Long) {
 				newValue = new TypedValue(op1.longValue() - 1L, operandTypedValue.getTypeDescriptor());

spring-expression/src/main/java/org/springframework/expression/spel/ast/OpDivide.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -35,6 +35,7 @@
  * @author Andy Clement
  * @author Juergen Hoeller
  * @author Giovanni Dall'Oglio Risso
+ * @author Sam Brannen
  * @since 3.0
  */
 public class OpDivide extends Operator {
@@ -49,10 +50,7 @@ public TypedValue getValueInternal(ExpressionState state) throws EvaluationExcep
 		Object leftOperand = getLeftOperand().getValueInternal(state).getValue();
 		Object rightOperand = getRightOperand().getValueInternal(state).getValue();
 
-		if (leftOperand instanceof Number && rightOperand instanceof Number) {
-			Number leftNumber = (Number) leftOperand;
-			Number rightNumber = (Number) rightOperand;
-
+		if (leftOperand instanceof Number leftNumber && rightOperand instanceof Number rightNumber) {
 			if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
 				BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
 				BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);

spring-expression/src/main/java/org/springframework/expression/spel/ast/OpGE.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -50,10 +50,7 @@ public BooleanTypedValue getValueInternal(ExpressionState state) throws Evaluati
 		this.leftActualDescriptor = CodeFlow.toDescriptorFromObject(left);
 		this.rightActualDescriptor = CodeFlow.toDescriptorFromObject(right);
 
-		if (left instanceof Number && right instanceof Number) {
-			Number leftNumber = (Number) left;
-			Number rightNumber = (Number) right;
-
+		if (left instanceof Number leftNumber && right instanceof Number rightNumber) {
 			if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
 				BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
 				BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);

spring-expression/src/main/java/org/springframework/expression/spel/ast/OpGT.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -50,10 +50,7 @@ public BooleanTypedValue getValueInternal(ExpressionState state) throws Evaluati
 		this.leftActualDescriptor = CodeFlow.toDescriptorFromObject(left);
 		this.rightActualDescriptor = CodeFlow.toDescriptorFromObject(right);
 
-		if (left instanceof Number && right instanceof Number) {
-			Number leftNumber = (Number) left;
-			Number rightNumber = (Number) right;
-
+		if (left instanceof Number leftNumber && right instanceof Number rightNumber) {
 			if (leftNumber instanceof BigDecimal || rightNumber instanceof BigDecimal) {
 				BigDecimal leftBigDecimal = NumberUtils.convertNumberToTargetClass(leftNumber, BigDecimal.class);
 				BigDecimal rightBigDecimal = NumberUtils.convertNumberToTargetClass(rightNumber, BigDecimal.class);