Internal adaptation to Deque semantics

spring-beans/src/main/java/org/springframework/beans/factory/xml/ParserContext.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -47,7 +47,7 @@ public final class ParserContext {
 	@Nullable
 	private BeanDefinition containingBeanDefinition;
 
-	private final Deque<ComponentDefinition> containingComponents = new ArrayDeque<>();
+	private final Deque<CompositeComponentDefinition> containingComponents = new ArrayDeque<>();
 
 
 	public ParserContext(XmlReaderContext readerContext, BeanDefinitionParserDelegate delegate) {
@@ -96,8 +96,7 @@ public final class ParserContext {
 
 	@Nullable
 	public CompositeComponentDefinition getContainingComponent() {
-		return (!this.containingComponents.isEmpty() ?
+		return this.containingComponents.peek();
-				(CompositeComponentDefinition) this.containingComponents.getLast() : null);
 	}
 
 	public void pushContainingComponent(CompositeComponentDefinition containingComponent) {
@@ -105,7 +104,7 @@ public final class ParserContext {
 	}
 
 	public CompositeComponentDefinition popContainingComponent() {
-		return (CompositeComponentDefinition) this.containingComponents.pop();
+		return this.containingComponents.pop();
 	}
 
 	public void popAndRegisterContainingComponent() {

spring-context/src/main/java/org/springframework/validation/AbstractErrors.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -20,9 +20,9 @@ import java.io.Serializable;
 import java.util.ArrayDeque;
 import java.util.Collections;
 import java.util.Deque;
-import java.util.EmptyStackException;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.NoSuchElementException;
 
 import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
@@ -62,12 +62,12 @@ public abstract class AbstractErrors implements Errors, Serializable {
 	}
 
 	@Override
-	public void popNestedPath() throws IllegalArgumentException {
+	public void popNestedPath() throws IllegalStateException {
 		try {
 			String formerNestedPath = this.nestedPathStack.pop();
 			doSetNestedPath(formerNestedPath);
 		}
-		catch (EmptyStackException ex) {
+		catch (NoSuchElementException ex) {
 			throw new IllegalStateException("Cannot pop nested path: no nested path on stack");
 		}
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -23,6 +23,7 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.NoSuchElementException;
 
 import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.expression.EvaluationContext;
@@ -49,6 +50,7 @@ import org.springframework.util.CollectionUtils;
  * nodes might need.
  *
  * @author Andy Clement
+ * @author Juergen Hoeller
  * @since 3.0
  */
 public class ExpressionState {
@@ -118,8 +120,13 @@ public class ExpressionState {
 		if (this.contextObjects == null) {
 			this.contextObjects = new ArrayDeque<>();
 		}
+		try {
 			this.contextObjects.pop();
 		}
+		catch (NoSuchElementException ex) {
+			throw new IllegalStateException("Cannot pop active context object: stack is empty");
+		}
+	}
 
 	public TypedValue getRootContextObject() {
 		return this.rootObject;
@@ -197,9 +204,7 @@ public class ExpressionState {
 
 	@Nullable
 	public Object lookupLocalVariable(String name) {
-		int scopeNumber = initVariableScopes().size() - 1;
+		for (VariableScope scope : initVariableScopes()) {
-		for (int i = scopeNumber; i >= 0; i--) {
-			VariableScope scope = initVariableScopes().get(i);
 			if (scope.definesVariable(name)) {
 				return scope.lookupVariable(name);
 			}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -16,7 +16,6 @@
 
 package org.springframework.expression.spel;
 
-import java.util.EmptyStackException;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -36,6 +35,7 @@ import static org.junit.Assert.*;
  * Tests for the expression state object - some features are not yet exploited in the language (eg nested scopes)
  *
  * @author Andy Clement
+ * @author Juergen Hoeller
  */
 public class ExpressionStateTests extends AbstractExpressionTests {
 
@@ -141,7 +141,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 			state.popActiveContextObject();
 			fail("stack should be empty...");
 		}
-		catch (EmptyStackException ese) {
+		catch (IllegalStateException ese) {
 			// success
 		}
 
@@ -217,7 +217,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	}
 
 	@Test
-	public void testOperators() throws Exception {
+	public void testOperators() {
 		ExpressionState state = getState();
 		try {
 			state.operate(Operation.ADD,1,2);