INT-2888 Fix MapToObjectTransformerParser CL Issue

In the parent-child environment configuration that relies on class names may produce
a `ClassNotFoundException`.

* remove usage of `ClassLoader` in the `MapToObjectTransformerParser` and allow to use the `ConversionService` from application context
* remove deprecation from `MapToObjectTransformer`
* refactor `MapToObjectTransformer` to use `IntegrationObjectSupport#getConversionService()`
* remove fallback to the `beanFactory#getConversionService()` in the `ExpressionUtils`

JIRA: https://jira.springsource.org/browse/INT-2888

INT-2928: Do Not Fallback to BF's ConversionService

* Polishing according PR's comments
* Important note about `conversionService` & `integrationConversionService` beans
* Link a JIRA about elimination of `BeanFactory`'s `ConversionService` usage
* Add a note to the 2.2-3.0 Migration Guide

JIRA: https://jira.springsource.org/browse/INT-2928

INT-2888 Doc Polishing

spring-integration-core/src/main/java/org/springframework/integration/config/xml/MapToObjectTransformerParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -18,13 +18,12 @@ package org.springframework.integration.config.xml;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.integration.transformer.MapToObjectTransformer;
-import org.springframework.util.Assert;
-import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 import org.w3c.dom.Element;
 
 /**
  * @author Oleg Zhurakousky
+ * @author Artem Bilan
  * @since 2.0
  */
 public class MapToObjectTransformerParser extends AbstractTransformerParser {
@@ -38,17 +37,17 @@ public class MapToObjectTransformerParser extends AbstractTransformerParser {
 	protected void parseTransformer(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
 		String ref = element.getAttribute("ref");
 		String type = element.getAttribute("type");
-		Assert.isTrue(!(StringUtils.hasText(ref) && StringUtils.hasText(type)), 
-				"'type' and 'ref' attributes are mutually-exclusive, but both have valid values; type: " + type + "; ref:");
-		if (StringUtils.hasText(ref)){
+		if (StringUtils.hasText(ref) && StringUtils.hasText(type)) {
+			parserContext.getReaderContext().error("'type' and 'ref' attributes are mutually-exclusive, " +
+					"but both have valid values; type: " + type + "; ref: " + ref,
+					IntegrationNamespaceUtils.createElementDescription(element));
+		}
+		if (StringUtils.hasText(ref)) {
 			builder.getBeanDefinition().getConstructorArgumentValues().addGenericArgumentValue(ref, "java.lang.String");
-		} else if (StringUtils.hasText(type)){
-			ClassLoader classLoader = parserContext.getReaderContext().getBeanClassLoader();
-			if (classLoader == null) {
-				classLoader = this.getClass().getClassLoader();
-			}
-			Class<?> clazz = ClassUtils.resolveClassName(type, classLoader);
-			builder.getBeanDefinition().getConstructorArgumentValues().addGenericArgumentValue(clazz, "java.lang.Class");
+		}
+		else if (StringUtils.hasText(type)) {
+			builder.getBeanDefinition().getConstructorArgumentValues().addGenericArgumentValue(type, "java.lang.Class");
 		}
 	}
+
 }

spring-integration-core/src/main/java/org/springframework/integration/expression/ExpressionUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -17,7 +17,6 @@
 package org.springframework.integration.expression;
 
 import org.springframework.beans.factory.BeanFactory;
-import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.context.expression.BeanFactoryResolver;
 import org.springframework.context.expression.MapAccessor;
 import org.springframework.core.convert.ConversionService;
@@ -32,6 +31,7 @@ import org.springframework.integration.context.IntegrationContextUtils;
  *
  * @author Gary Russell
  * @author Oleg Zhurakousky
+ * @author Artem Bilan
  * @since 2.2
  */
 public abstract class ExpressionUtils {
@@ -97,10 +97,7 @@ public abstract class ExpressionUtils {
 	 * @return the evaluation context.
 	 */
 	public static StandardEvaluationContext createStandardEvaluationContext(BeanFactory beanFactory) {
-		ConversionService conversionService = IntegrationContextUtils.getConversionService(beanFactory);
-		if (conversionService == null && beanFactory instanceof ConfigurableListableBeanFactory){
-			conversionService = ((ConfigurableListableBeanFactory)beanFactory).getConversionService();
-		}
-		return createStandardEvaluationContext(new BeanFactoryResolver(beanFactory), conversionService);
+		return createStandardEvaluationContext(new BeanFactoryResolver(beanFactory),
+				IntegrationContextUtils.getConversionService(beanFactory));
 	}
 }

spring-integration-core/src/main/java/org/springframework/integration/transformer/MapToObjectTransformer.java

@@ -20,7 +20,6 @@ import java.util.Map;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.MutablePropertyValues;
-import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.util.Assert;
@@ -36,14 +35,15 @@ import org.springframework.validation.DataBinder;
  * to types that represent the properties of the Object.
  *
  * @author Oleg Zhurakousky
- * @author Gunnar Hillert
+ * @author Artem Bilan
  * @since 2.0
  */
-public class MapToObjectTransformer extends AbstractPayloadTransformer<Map<?,?>, Object>{
+public class MapToObjectTransformer extends AbstractPayloadTransformer<Map<?, ?>, Object> {
 
 	private final Class<?> targetClass;
 
 	private final String targetBeanName;
+
 	/**
 	 * @param targetClass
 	 */
@@ -52,6 +52,7 @@ public class MapToObjectTransformer extends AbstractPayloadTransformer<Map<?,?>,
 		this.targetClass = targetClass;
 		this.targetBeanName = null;
 	}
+
 	/**
 	 * @param beanName
 	 */
@@ -60,31 +61,30 @@ public class MapToObjectTransformer extends AbstractPayloadTransformer<Map<?,?>,
 		this.targetBeanName = beanName;
 		this.targetClass = null;
 	}
-	/*
-	 * (non-Javadoc)
-	 * @see org.springframework.integration.transformer.AbstractPayloadTransformer#transformPayload(java.lang.Object)
-	 */
-	protected Object transformPayload(Map<?,?> payload) throws Exception {
+
+	@Override
+	protected Object transformPayload(Map<?, ?> payload) throws Exception {
 		Object target = (this.targetClass != null)
 				? BeanUtils.instantiate(this.targetClass)
 				: this.getBeanFactory().getBean(this.targetBeanName);
+
 		DataBinder binder = new DataBinder(target);
-		ConversionService conversionService = null;
-		if (this.getBeanFactory() instanceof ConfigurableBeanFactory){
-			conversionService = ((ConfigurableBeanFactory)this.getBeanFactory()).getConversionService();
-		}
-		if (conversionService == null){
+		ConversionService conversionService = this.getConversionService();
+		if (conversionService == null) {
 			conversionService = new DefaultConversionService();
 		}
 		binder.setConversionService(conversionService);
 		binder.bind(new MutablePropertyValues(payload));
+
 		return target;
 	}
 
-	protected void onInit(){
+	@Override
+	protected void onInit() {
 		if (StringUtils.hasText(this.targetBeanName)) {
 			Assert.isTrue(this.getBeanFactory().isPrototype(this.targetBeanName),
 					"target bean [" + targetBeanName + "] must have 'prototype' scope");
 		}
 	}
+
 }

spring-integration-core/src/test/java/org/springframework/integration/config/xml/MapToObjectTransformerParserTests-context.xml

@@ -9,27 +9,27 @@
 	<int:channel id="output">
 		<int:queue/>
 	</int:channel>
-	
-	<int:map-to-object-transformer input-channel="input" 
-	                               output-channel="output" 
+
+	<int:map-to-object-transformer input-channel="input"
+	                               output-channel="output"
 	                               type="org.springframework.integration.config.xml.MapToObjectTransformerParserTests$Person"/>
-	                               
+
 	<int:channel id="inputA"/>
 	<int:channel id="outputA">
 		<int:queue/>
 	</int:channel>
-	
-	<int:map-to-object-transformer input-channel="inputA" 
-	                               output-channel="outputA" 
+
+	<int:map-to-object-transformer input-channel="inputA"
+	                               output-channel="outputA"
 	                               ref="person"/>
-	                               
-	<bean id="conversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
+
+	<bean id="conversionService" name="integrationConversionService" class="org.springframework.context.support.ConversionServiceFactoryBean">
 		<property name="converters">
 			<list>
 				<bean class="org.springframework.integration.config.xml.MapToObjectTransformerParserTests$StringToAddressConverter" />
 			</list>
 		</property>
 	</bean>
-	                               
+
 	<bean id="person" class="org.springframework.integration.config.xml.MapToObjectTransformerParserTests$Person" scope="prototype"/>
 </beans>

spring-integration-core/src/test/java/org/springframework/integration/transformer/MapToObjectTransformerTests.java

@@ -20,43 +20,49 @@ import static junit.framework.Assert.assertEquals;
 import static junit.framework.Assert.assertNotNull;
 import static junit.framework.Assert.assertNull;
 
+import java.lang.reflect.Constructor;
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
 import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.Test;
-import org.springframework.beans.factory.config.ConfigurableBeanFactory;
-import org.springframework.beans.factory.support.DefaultListableBeanFactory;
+import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.core.convert.converter.Converter;
-import org.springframework.core.convert.support.DefaultConversionService;
-import org.springframework.core.convert.support.GenericConversionService;
+import org.springframework.core.convert.converter.ConverterRegistry;
 import org.springframework.integration.Message;
+import org.springframework.integration.context.IntegrationContextUtils;
 import org.springframework.integration.support.MessageBuilder;
+import org.springframework.integration.test.util.TestUtils;
+import org.springframework.util.ClassUtils;
+
 
 /**
  * @author Oleg Zhurakousky
  * @author Gunnar Hillert
- *
+ * @author Artem Bilan
  * @since 2.0
  */
-@SuppressWarnings({ "unchecked", "rawtypes" })
 public class MapToObjectTransformerTests {
 
-
 	@Test
-	public void testMapToObjectTransformation(){
-		Map map = new HashMap();
+	public void testMapToObjectTransformation() {
+		Map<String, Object> map = new HashMap<String, Object>();
 		map.put("fname", "Justin");
 		map.put("lname", "Case");
 		Address address = new Address();
 		address.setStreet("1123 Main st");
 		map.put("address", address);
 
-		Message message = MessageBuilder.withPayload(map).build();
+		Message<?> message = MessageBuilder.withPayload(map).build();
 
 		MapToObjectTransformer transformer = new MapToObjectTransformer(Person.class);
 		transformer.setBeanFactory(this.getBeanFactory());
-		Message newMessage = transformer.transform(message);
+		Message<?> newMessage = transformer.transform(message);
 		Person person = (Person) newMessage.getPayload();
 		assertNotNull(person);
 		assertEquals("Justin", person.getFname());
@@ -67,20 +73,20 @@ public class MapToObjectTransformerTests {
 	}
 
 	@Test
-	public void testMapToObjectTransformationWithPrototype(){
-		Map map = new HashMap();
+	public void testMapToObjectTransformationWithPrototype() {
+		Map<String, Object> map = new HashMap<String, Object>();
 		map.put("fname", "Justin");
 		map.put("lname", "Case");
 		Address address = new Address();
 		address.setStreet("1123 Main st");
 		map.put("address", address);
 
-		Message message = MessageBuilder.withPayload(map).build();
+		Message<?> message = MessageBuilder.withPayload(map).build();
 		StaticApplicationContext ac = new StaticApplicationContext();
 		ac.registerPrototype("person", Person.class);
 		MapToObjectTransformer transformer = new MapToObjectTransformer("person");
 		transformer.setBeanFactory(ac.getBeanFactory());
-		Message newMessage = transformer.transform(message);
+		Message<?> newMessage = transformer.transform(message);
 		Person person = (Person) newMessage.getPayload();
 		assertNotNull(person);
 		assertEquals("Justin", person.getFname());
@@ -91,20 +97,22 @@ public class MapToObjectTransformerTests {
 	}
 
 	@Test
-	public void testMapToObjectTransformationWithConversionService(){
-		Map map = new HashMap();
+	public void testMapToObjectTransformationWithConversionService() {
+		Map<String, Object> map = new HashMap<String, Object>();
 		map.put("fname", "Justin");
 		map.put("lname", "Case");
 		map.put("address", "1123 Main st");
 
-		Message message = MessageBuilder.withPayload(map).build();
+		Message<?> message = MessageBuilder.withPayload(map).build();
 
 		MapToObjectTransformer transformer = new MapToObjectTransformer(Person.class);
-		ConfigurableBeanFactory beanFactory = this.getBeanFactory();
-		((GenericConversionService)beanFactory.getConversionService()).addConverter(new StringToAddressConverter());
+		BeanFactory beanFactory = this.getBeanFactory();
+		ConverterRegistry conversionService =
+				beanFactory.getBean(IntegrationContextUtils.INTEGRATION_CONVERSION_SERVICE_BEAN_NAME, ConverterRegistry.class);
+		conversionService.addConverter(new StringToAddressConverter());
 		transformer.setBeanFactory(beanFactory);
 
-		Message newMessage = transformer.transform(message);
+		Message<?> newMessage = transformer.transform(message);
 		Person person = (Person) newMessage.getPayload();
 		assertNotNull(person);
 		assertEquals("Justin", person.getFname());
@@ -113,45 +121,73 @@ public class MapToObjectTransformerTests {
 		assertEquals("1123 Main st", person.getAddress().getStreet());
 	}
 
-	private ConfigurableBeanFactory getBeanFactory(){
-		DefaultListableBeanFactory beanFactory = new DefaultListableBeanFactory();
-		GenericConversionService conversionService = new DefaultConversionService();
-		beanFactory.setConversionService(conversionService);
-		return beanFactory;
+	private BeanFactory getBeanFactory() {
+		GenericApplicationContext ctx = TestUtils.createTestApplicationContext();
+		Constructor<?> constructorToUse = null;
+		try {
+			// Add the integrationConversionService (reflection needed because of package protection)
+			final Class<?> conversionServiceCreatorClass = ClassUtils.forName("org.springframework.integration.context.ConversionServiceCreator",
+					ClassUtils.getDefaultClassLoader());
+			constructorToUse = AccessController.doPrivileged(new PrivilegedExceptionAction<Constructor<?>>() {
+				public Constructor<?> run() throws Exception {
+					return conversionServiceCreatorClass.getDeclaredConstructor((Class[]) null);
+				}
+			});
+		}
+		catch (Exception e) {
+			throw new RuntimeException("Unexpected Privilege Exception: ", e);
+		}
+
+		ctx.addBeanFactoryPostProcessor((BeanFactoryPostProcessor) BeanUtils.instantiateClass(constructorToUse));
+		ctx.refresh();
+		return ctx;
 	}
 
-	public static class Person{
+	public static class Person {
+
 		private String fname;
+
 		private String lname;
+
 		private String ssn;
+
 		private Address address;
+
 		public String getSsn() {
 			return ssn;
 		}
+
 		public void setSsn(String ssn) {
 			this.ssn = ssn;
 		}
+
 		public String getFname() {
 			return fname;
 		}
+
 		public void setFname(String fname) {
 			this.fname = fname;
 		}
+
 		public String getLname() {
 			return lname;
 		}
+
 		public void setLname(String lname) {
 			this.lname = lname;
 		}
+
 		public Address getAddress() {
 			return address;
 		}
+
 		public void setAddress(Address address) {
 			this.address = address;
 		}
 	}
 
 	public static class Address {
+
 		private String street;
 
 		public String getStreet() {
@@ -163,7 +199,8 @@ public class MapToObjectTransformerTests {
 		}
 	}
 
-	public class StringToAddressConverter implements Converter<String, Address>{
+	public class StringToAddressConverter implements Converter<String, Address> {
+
 		public Address convert(String source) {
 			Address address = new Address();
 			address.setStreet(source);