introduced "lenientConstructorResolution" flag (SPR-5816)

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanDefinition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.beans.factory.support;
 
-import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
@@ -144,6 +143,8 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 
 	private ConstructorArgumentValues constructorArgumentValues;
 
+	private boolean lenientConstructorResolution = true;
+
 	private MutablePropertyValues propertyValues;
 
 	private MethodOverrides methodOverrides = new MethodOverrides();
@@ -168,7 +169,6 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 
 	private Resource resource;
 
-
 	/**
 	 * Create a new AbstractBeanDefinition with default settings.
 	 */
@@ -226,6 +226,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 			setAutowireCandidate(originalAbd.isAutowireCandidate());
 			copyQualifiersFrom(originalAbd);
 			setPrimary(originalAbd.isPrimary());
+			setLenientConstructorResolution(originalAbd.isLenientConstructorResolution());
 			setInitMethodName(originalAbd.getInitMethodName());
 			setEnforceInitMethod(originalAbd.isEnforceInitMethod());
 			setDestroyMethodName(originalAbd.getDestroyMethodName());
@@ -297,6 +298,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 			setPrimary(otherAbd.isPrimary());
 			setDependencyCheck(otherAbd.getDependencyCheck());
 			setDependsOn(otherAbd.getDependsOn());
+			setLenientConstructorResolution(otherAbd.isLenientConstructorResolution());
 			if (otherAbd.getInitMethodName() != null) {
 				setInitMethodName(otherAbd.getInitMethodName());
 				setEnforceInitMethod(otherAbd.isEnforceInitMethod());
@@ -642,7 +644,7 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 	 * Copy the qualifiers from the supplied AbstractBeanDefinition to this bean definition.
 	 * @param source the AbstractBeanDefinition to copy from
 	 */
-	protected void copyQualifiersFrom(AbstractBeanDefinition source) {
+	public void copyQualifiersFrom(AbstractBeanDefinition source) {
 		Assert.notNull(source, "Source must not be null");
 		this.qualifiers.putAll(source.qualifiers);
 	}
@@ -670,6 +672,23 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 		return !this.constructorArgumentValues.isEmpty();
 	}
 
+	/**
+	 * Specify whether to resolve constructors in lenient mode (<code>true</code>,
+	 * which is the default) or to switch to strict resolution (throwing an exception
+	 * in case of ambigious constructors that all match when converting the arguments,
+	 * whereas lenient mode would use the one with the 'closest' type matches).
+	 */
+	public void setLenientConstructorResolution(boolean lenientConstructorResolution) {
+		this.lenientConstructorResolution = lenientConstructorResolution;
+	}
+
+	/**
+	 * Return whether to resolve constructors in lenient mode or in strict mode.
+	 */
+	public boolean isLenientConstructorResolution() {
+		return this.lenientConstructorResolution;
+	}
+
 	/**
 	 * Specify property values for this bean, if any.
 	 */

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/ConstructorResolver.java

@@ -226,6 +226,12 @@ class ConstructorResolver {
 					argsToUse = args.arguments;
 					minTypeDiffWeight = typeDiffWeight;
 				}
+				else if (typeDiffWeight < Integer.MAX_VALUE && typeDiffWeight == minTypeDiffWeight &&
+						!mbd.isLenientConstructorResolution()) {
+					throw new BeanCreationException(mbd.getResourceDescription(), beanName,
+							"Ambiguous constructor matches found in bean '" + beanName + "' " +
+							"(hint: specify index/type/name arguments for simple parameters to avoid type ambiguities)");
+				}
 			}
 
 			if (constructorToUse == null) {
@@ -561,21 +567,24 @@ class ConstructorResolver {
 				// We found a potential match - let's give it a try.
 				// Do not consider the same value definition multiple times!
 				usedValueHolders.add(valueHolder);
-				args.rawArguments[paramIndex] = valueHolder.getValue();
+				ConstructorArgumentValues.ValueHolder sourceHolder =
+						(ConstructorArgumentValues.ValueHolder) valueHolder.getSource();
+				Object originalValue = valueHolder.getValue();
+				Object sourceValue = sourceHolder.getValue();
 				if (valueHolder.isConverted()) {
 					Object convertedValue = valueHolder.getConvertedValue();
+					args.rawArguments[paramIndex] =
+							(mbd.isLenientConstructorResolution() ? originalValue : convertedValue);
 					args.arguments[paramIndex] = convertedValue;
 					args.preparedArguments[paramIndex] = convertedValue;
 				}
 				else {
 					try {
-						Object originalValue = valueHolder.getValue();
 						Object convertedValue = converter.convertIfNecessary(originalValue, paramType,
 								MethodParameter.forMethodOrConstructor(methodOrCtor, paramIndex));
+						args.rawArguments[paramIndex] =
+								(mbd.isLenientConstructorResolution() ? originalValue : convertedValue);
 						args.arguments[paramIndex] = convertedValue;
-						ConstructorArgumentValues.ValueHolder sourceHolder =
-								(ConstructorArgumentValues.ValueHolder) valueHolder.getSource();
-						Object sourceValue = sourceHolder.getValue();
 						if (originalValue == sourceValue || sourceValue instanceof TypedStringValue) {
 							// Either a converted value or still the original one: store converted value.
 							sourceHolder.setConvertedValue(convertedValue);

org.springframework.context/src/test/java/org/springframework/beans/factory/xml/XmlBeanFactoryTests-constructorArg.xml

@@ -170,6 +170,11 @@
 		<constructor-arg index="1"><value>true</value></constructor-arg>
 	</bean>
 
+	<bean id="beanWithDoubleBooleanNoType" class="org.springframework.beans.factory.xml.XmlBeanFactoryTests$DoubleBooleanConstructorBean" scope="prototype">
+		<constructor-arg index="0"><value>false</value></constructor-arg>
+		<constructor-arg index="1"><value>true</value></constructor-arg>
+	</bean>
+
 	<bean id="constructorArray" class="org.springframework.beans.factory.xml.XmlBeanFactoryTests$ConstructorArrayTestBean">
 		<constructor-arg type="int[]">
 			<array value-type="int">

org.springframework.context/src/test/java/org/springframework/beans/factory/xml/XmlBeanFactoryTests.java

@@ -56,6 +56,7 @@ import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.beans.factory.support.DefaultListableBeanFactory;
 import org.springframework.beans.factory.support.MethodReplacer;
 import org.springframework.beans.factory.support.RootBeanDefinition;
+import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.FileSystemResource;
 import org.springframework.core.io.UrlResource;
@@ -1363,6 +1364,21 @@ public final class XmlBeanFactoryTests {
 		assertEquals(Boolean.TRUE, bean.boolean2);
 	}
 
+	public @Test void testDoubleBooleanNoType() {
+		XmlBeanFactory xbf = new XmlBeanFactory(CONSTRUCTOR_ARG_CONTEXT);
+		AbstractBeanDefinition bd = (AbstractBeanDefinition) xbf.getBeanDefinition("beanWithDoubleBooleanNoType");
+		bd.setLenientConstructorResolution(false);
+		try {
+			xbf.getBean("beanWithDoubleBooleanNoType");
+			fail("Should have thrown BeanCreationException");
+		}
+		catch (BeanCreationException ex) {
+			// expected
+			ex.printStackTrace();
+			assertTrue(ex.getMostSpecificCause().getMessage().contains("Ambiguous"));
+		}
+	}
+
 	public @Test void testPrimitiveConstructorArray() {
 		XmlBeanFactory xbf = new XmlBeanFactory(CONSTRUCTOR_ARG_CONTEXT);
 		ConstructorArrayTestBean bean = (ConstructorArrayTestBean) xbf.getBean("constructorArray");
@@ -1603,6 +1619,10 @@ public final class XmlBeanFactoryTests {
 			this.boolean1 = b1;
 			this.boolean2 = b2;
 		}
+
+		public DoubleBooleanConstructorBean(String s1, String s2) {
+			throw new IllegalStateException("Don't pick this constructor");
+		}
 	}