From 7591406f2e6d854b248dc4d978219613a2b940c7 Mon Sep 17 00:00:00 2001
From: Mark Fisher <markfisher@vmware.com>
Date: Sat, 28 Feb 2009 16:37:02 +0000
Subject: [PATCH] Renamed 'prototypeBeanName' to 'targetBeanName' and added
 eager validation of its non-singleton scope.

---
 .../ServletRequestBindingTransformer.java     | 48 ++++++++++++++-----
 1 file changed, 35 insertions(+), 13 deletions(-)

diff --git a/org.springframework.integration.http/src/main/java/org/springframework/integration/http/transformer/ServletRequestBindingTransformer.java b/org.springframework.integration.http/src/main/java/org/springframework/integration/http/transformer/ServletRequestBindingTransformer.java
index 48bdc9a899..976cb0931f 100644
--- a/org.springframework.integration.http/src/main/java/org/springframework/integration/http/transformer/ServletRequestBindingTransformer.java
+++ b/org.springframework.integration.http/src/main/java/org/springframework/integration/http/transformer/ServletRequestBindingTransformer.java
@@ -23,6 +23,7 @@ import javax.servlet.http.HttpServletRequest;
 import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.integration.transformer.AbstractPayloadTransformer;
 import org.springframework.util.Assert;
 import org.springframework.web.bind.ServletRequestDataBinder;
@@ -32,22 +33,25 @@ import org.springframework.web.servlet.handler.DispatcherServletWebRequest;
 /**
  * Message Transformer that expects a {@link HttpServletRequest} as input and binds
  * its parameter map to a target instance. The target instance may be a non-singleton
- * bean as specified by the {@link #prototypeBeanName} property. Otherwise, this
- * transformer's {@link #type} must provide a default no-arg constructor.
+ * bean as specified by the {@link #setTargetBeanName(String) 'targetBeanName'} property.
+ * Otherwise, this transformer's target type must provide a default no-arg constructor.
  * 
  * @author Mark Fisher
  * @since 1.0.2
  */
-public class ServletRequestBindingTransformer<T> extends AbstractPayloadTransformer<HttpServletRequest, T> implements BeanFactoryAware {
+public class ServletRequestBindingTransformer<T> extends AbstractPayloadTransformer<HttpServletRequest, T>
+		implements BeanFactoryAware, InitializingBean {
 
 	private final Class<T> targetType;
 
-	private volatile String prototypeBeanName;
+	private volatile String targetBeanName;
 
 	private volatile WebBindingInitializer webBindingInitializer;
 
 	private volatile BeanFactory beanFactory;
 
+	private volatile boolean validated;
+
 
 	public ServletRequestBindingTransformer(Class<T> targetType) {
 		Assert.notNull(targetType, "targetType must not be null");
@@ -55,8 +59,15 @@ public class ServletRequestBindingTransformer<T> extends AbstractPayloadTransfor
 	}
 
 
-	public void setPrototypeBeanName(String prototypeBeanName) {
-		this.prototypeBeanName = prototypeBeanName;
+	/**
+	 * Specify the name of a bean definition to use when creating the target
+	 * instance. The bean must <em>not</em> be a singleton, and it must be
+	 * compatible with the {@link #targetType}.
+	 * <p>If no 'targetBeanName' value is provided, the target type must
+	 * provide a default, no-arg constructor. 
+	 */
+	public void setTargetBeanName(String targetBeanName) {
+		this.targetBeanName = targetBeanName;
 	}
 
 	public void setWebBindingInitializer(WebBindingInitializer webBindingInitializer) {
@@ -67,6 +78,20 @@ public class ServletRequestBindingTransformer<T> extends AbstractPayloadTransfor
 		this.beanFactory = beanFactory;
 	}
 
+	public final void afterPropertiesSet() {
+		this.validateTargetBeanIfNecessary();
+	}
+
+	private void validateTargetBeanIfNecessary() {
+		if (this.targetBeanName != null && !this.validated) {
+			Assert.notNull(this.beanFactory, "beanFactory is required for binding to a bean");
+			if (this.beanFactory.isSingleton(this.targetBeanName)) {
+				throw new IllegalArgumentException("binding target bean must not be a singleton");
+			}
+			this.validated = true;
+		}
+	}
+
 	@Override
 	@SuppressWarnings("unchecked")
 	protected T transformPayload(HttpServletRequest request) throws Exception {
@@ -86,14 +111,11 @@ public class ServletRequestBindingTransformer<T> extends AbstractPayloadTransfor
 
 	@SuppressWarnings("unchecked")
 	private Object getTarget() throws InstantiationException, IllegalAccessException {
-		if (this.prototypeBeanName == null) {
-			return this.targetType.newInstance();
+		if (this.targetBeanName != null) {
+			this.validateTargetBeanIfNecessary();
+			return (T) this.beanFactory.getBean(this.targetBeanName, this.targetType);
 		}
-		Assert.notNull(this.beanFactory, "beanFactory is required for binding to a prototype bean");
-		if (this.beanFactory.isSingleton(this.prototypeBeanName)) {
-			throw new IllegalArgumentException("binding target bean must not be a singleton");
-		}
-		return (T) this.beanFactory.getBean(this.prototypeBeanName, this.targetType);
+		return this.targetType.newInstance();
 	}
 
 }