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() ?
-				(CompositeComponentDefinition) this.containingComponents.getLast() : null);
+		return this.containingComponents.peek();
 	}
 
 	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 {
@@ -118,7 +120,12 @@ public class ExpressionState {
 		if (this.contextObjects == null) {
 			this.contextObjects = new ArrayDeque<>();
 		}
-		this.contextObjects.pop();
+		try {
+			this.contextObjects.pop();
+		}
+		catch (NoSuchElementException ex) {
+			throw new IllegalStateException("Cannot pop active context object: stack is empty");
+		}
 	}
 
 	public TypedValue getRootContextObject() {
@@ -197,9 +204,7 @@ public class ExpressionState {
 
 	@Nullable
 	public Object lookupLocalVariable(String name) {
-		int scopeNumber = initVariableScopes().size() - 1;
-		for (int i = scopeNumber; i >= 0; i--) {
-			VariableScope scope = initVariableScopes().get(i);
+		for (VariableScope scope : initVariableScopes()) {
 			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 {
 
@@ -43,7 +43,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	public void testConstruction() {
 		EvaluationContext context = TestScenarioCreator.getTestEvaluationContext();
 		ExpressionState state = new ExpressionState(context);
-		assertEquals(context,state.getEvaluationContext());
+		assertEquals(context, state.getEvaluationContext());
 	}
 
 	// Local variables are in variable scopes which come and go during evaluation.  Normal variables are
@@ -58,107 +58,107 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 
 		state.setLocalVariable("foo",34);
 		value = state.lookupLocalVariable("foo");
-		assertEquals(34,value);
+		assertEquals(34, value);
 
-		state.setLocalVariable("foo",null);
+		state.setLocalVariable("foo", null);
 		value = state.lookupLocalVariable("foo");
-		assertEquals(null,value);
+		assertEquals(null, value);
 	}
 
 	@Test
 	public void testVariables() {
 		ExpressionState state = getState();
 		TypedValue typedValue = state.lookupVariable("foo");
-		assertEquals(TypedValue.NULL,typedValue);
+		assertEquals(TypedValue.NULL, typedValue);
 
 		state.setVariable("foo",34);
 		typedValue = state.lookupVariable("foo");
-		assertEquals(34,typedValue.getValue());
-		assertEquals(Integer.class,typedValue.getTypeDescriptor().getType());
+		assertEquals(34, typedValue.getValue());
+		assertEquals(Integer.class, typedValue.getTypeDescriptor().getType());
 
 		state.setVariable("foo","abc");
 		typedValue = state.lookupVariable("foo");
-		assertEquals("abc",typedValue.getValue());
-		assertEquals(String.class,typedValue.getTypeDescriptor().getType());
+		assertEquals("abc", typedValue.getValue());
+		assertEquals(String.class, typedValue.getTypeDescriptor().getType());
 	}
 
 	@Test
 	public void testNoVariableInteference() {
 		ExpressionState state = getState();
 		TypedValue typedValue = state.lookupVariable("foo");
-		assertEquals(TypedValue.NULL,typedValue);
+		assertEquals(TypedValue.NULL, typedValue);
 
 		state.setLocalVariable("foo",34);
 		typedValue = state.lookupVariable("foo");
-		assertEquals(TypedValue.NULL,typedValue);
+		assertEquals(TypedValue.NULL, typedValue);
 
-		state.setVariable("goo","hello");
+		state.setVariable("goo", "hello");
 		assertNull(state.lookupLocalVariable("goo"));
 	}
 
 	@Test
 	public void testLocalVariableNestedScopes() {
 		ExpressionState state = getState();
-		assertEquals(null,state.lookupLocalVariable("foo"));
+		assertEquals(null, state.lookupLocalVariable("foo"));
 
 		state.setLocalVariable("foo",12);
-		assertEquals(12,state.lookupLocalVariable("foo"));
+		assertEquals(12, state.lookupLocalVariable("foo"));
 
 		state.enterScope(null);
-		assertEquals(12,state.lookupLocalVariable("foo")); // found in upper scope
+		assertEquals(12, state.lookupLocalVariable("foo"));  // found in upper scope
 
 		state.setLocalVariable("foo","abc");
-		assertEquals("abc",state.lookupLocalVariable("foo")); // found in nested scope
+		assertEquals("abc", state.lookupLocalVariable("foo"));  // found in nested scope
 
 		state.exitScope();
-		assertEquals(12,state.lookupLocalVariable("foo")); // found in nested scope
+		assertEquals(12, state.lookupLocalVariable("foo"));  // found in nested scope
 	}
 
 	@Test
 	public void testRootContextObject() {
 		ExpressionState state = getState();
-		assertEquals(Inventor.class,state.getRootContextObject().getValue().getClass());
+		assertEquals(Inventor.class, state.getRootContextObject().getValue().getClass());
 
 		// although the root object is being set on the evaluation context, the value in the 'state' remains what it was when constructed
 		((StandardEvaluationContext) state.getEvaluationContext()).setRootObject(null);
-		assertEquals(Inventor.class,state.getRootContextObject().getValue().getClass());
+		assertEquals(Inventor.class, state.getRootContextObject().getValue().getClass());
 		// assertEquals(null, state.getRootContextObject().getValue());
 
 		state = new ExpressionState(new StandardEvaluationContext());
-		assertEquals(TypedValue.NULL,state.getRootContextObject());
+		assertEquals(TypedValue.NULL, state.getRootContextObject());
 
 
-		((StandardEvaluationContext)state.getEvaluationContext()).setRootObject(null);
-		assertEquals(null,state.getRootContextObject().getValue());
+		((StandardEvaluationContext) state.getEvaluationContext()).setRootObject(null);
+		assertEquals(null, state.getRootContextObject().getValue());
 	}
 
 	@Test
 	public void testActiveContextObject() {
 		ExpressionState state = getState();
-		assertEquals(state.getRootContextObject().getValue(),state.getActiveContextObject().getValue());
+		assertEquals(state.getRootContextObject().getValue(), state.getActiveContextObject().getValue());
 
 		try {
 			state.popActiveContextObject();
 			fail("stack should be empty...");
 		}
-		catch (EmptyStackException ese) {
+		catch (IllegalStateException ese) {
 			// success
 		}
 
 		state.pushActiveContextObject(new TypedValue(34));
-		assertEquals(34,state.getActiveContextObject().getValue());
+		assertEquals(34, state.getActiveContextObject().getValue());
 
 		state.pushActiveContextObject(new TypedValue("hello"));
-		assertEquals("hello",state.getActiveContextObject().getValue());
+		assertEquals("hello", state.getActiveContextObject().getValue());
 
 		state.popActiveContextObject();
-		assertEquals(34,state.getActiveContextObject().getValue());
+		assertEquals(34, state.getActiveContextObject().getValue());
 
 		state.popActiveContextObject();
-		assertEquals(state.getRootContextObject().getValue(),state.getActiveContextObject().getValue());
+		assertEquals(state.getRootContextObject().getValue(), state.getActiveContextObject().getValue());
 
 		state = new ExpressionState(new StandardEvaluationContext());
-		assertEquals(TypedValue.NULL,state.getActiveContextObject());
+		assertEquals(TypedValue.NULL, state.getActiveContextObject());
 	}
 
 	@Test
@@ -167,14 +167,14 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 		assertNull(state.lookupLocalVariable("foo"));
 
 		state.enterScope("foo",34);
-		assertEquals(34,state.lookupLocalVariable("foo"));
+		assertEquals(34, state.lookupLocalVariable("foo"));
 
 		state.enterScope(null);
-		state.setLocalVariable("foo",12);
-		assertEquals(12,state.lookupLocalVariable("foo"));
+		state.setLocalVariable("foo", 12);
+		assertEquals(12, state.lookupLocalVariable("foo"));
 
 		state.exitScope();
-		assertEquals(34,state.lookupLocalVariable("foo"));
+		assertEquals(34, state.lookupLocalVariable("foo"));
 
 		state.exitScope();
 		assertNull(state.lookupLocalVariable("goo"));
@@ -187,8 +187,8 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 		// supplied should override root on context
 		ExpressionState state = new ExpressionState(ctx,new TypedValue("i am a string"));
 		TypedValue stateRoot = state.getRootContextObject();
-		assertEquals(String.class,stateRoot.getTypeDescriptor().getType());
-		assertEquals("i am a string",stateRoot.getValue());
+		assertEquals(String.class, stateRoot.getTypeDescriptor().getType());
+		assertEquals("i am a string", stateRoot.getValue());
 	}
 
 	@Test
@@ -198,17 +198,17 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 		assertNull(state.lookupLocalVariable("goo"));
 
 		Map<String,Object> m = new HashMap<>();
-		m.put("foo",34);
-		m.put("goo","abc");
+		m.put("foo", 34);
+		m.put("goo", "abc");
 
 		state.enterScope(m);
-		assertEquals(34,state.lookupLocalVariable("foo"));
-		assertEquals("abc",state.lookupLocalVariable("goo"));
+		assertEquals(34, state.lookupLocalVariable("foo"));
+		assertEquals("abc", state.lookupLocalVariable("goo"));
 
 		state.enterScope(null);
 		state.setLocalVariable("foo",12);
-		assertEquals(12,state.lookupLocalVariable("foo"));
-		assertEquals("abc",state.lookupLocalVariable("goo"));
+		assertEquals(12, state.lookupLocalVariable("foo"));
+		assertEquals("abc", state.lookupLocalVariable("goo"));
 
 		state.exitScope();
 		state.exitScope();
@@ -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);
@@ -225,7 +225,7 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 		}
 		catch (EvaluationException ee) {
 			SpelEvaluationException sEx = (SpelEvaluationException)ee;
-			assertEquals(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES,sEx.getMessageCode());
+			assertEquals(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES, sEx.getMessageCode());
 		}
 
 		try {
@@ -234,28 +234,28 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 		}
 		catch (EvaluationException ee) {
 			SpelEvaluationException sEx = (SpelEvaluationException)ee;
-			assertEquals(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES,sEx.getMessageCode());
+			assertEquals(SpelMessage.OPERATOR_NOT_SUPPORTED_BETWEEN_TYPES, sEx.getMessageCode());
 		}
 	}
 
 	@Test
 	public void testComparator() {
 		ExpressionState state = getState();
-		assertEquals(state.getEvaluationContext().getTypeComparator(),state.getTypeComparator());
+		assertEquals(state.getEvaluationContext().getTypeComparator(), state.getTypeComparator());
 	}
 
 	@Test
 	public void testTypeLocator() throws EvaluationException {
 		ExpressionState state = getState();
 		assertNotNull(state.getEvaluationContext().getTypeLocator());
-		assertEquals(Integer.class,state.findType("java.lang.Integer"));
+		assertEquals(Integer.class, state.findType("java.lang.Integer"));
 		try {
 			state.findType("someMadeUpName");
 			fail("Should have failed to find it");
 		}
 		catch (EvaluationException ee) {
 			SpelEvaluationException sEx = (SpelEvaluationException)ee;
-			assertEquals(SpelMessage.TYPE_NOT_FOUND,sEx.getMessageCode());
+			assertEquals(SpelMessage.TYPE_NOT_FOUND, sEx.getMessageCode());
 		}
 	}
 
@@ -263,16 +263,16 @@ public class ExpressionStateTests extends AbstractExpressionTests {
 	public void testTypeConversion() throws EvaluationException {
 		ExpressionState state = getState();
 		String s = (String) state.convertValue(34, TypeDescriptor.valueOf(String.class));
-		assertEquals("34",s);
+		assertEquals("34", s);
 
 		s = (String)state.convertValue(new TypedValue(34), TypeDescriptor.valueOf(String.class));
-		assertEquals("34",s);
+		assertEquals("34", s);
 	}
 
 	@Test
 	public void testPropertyAccessors() {
 		ExpressionState state = getState();
-		assertEquals(state.getEvaluationContext().getPropertyAccessors(),state.getPropertyAccessors());
+		assertEquals(state.getEvaluationContext().getPropertyAccessors(), state.getPropertyAccessors());
 	}
 
 	/**