DATACMNS-718 - Class loader improvements in ProxyProjectionFactory.

ProxyProjectionFactory now implements ResourceLoaderAware to be able to use the class loader used by the framework. SpringDataWebConfiguration now forwards the Application context as ResourceLoader through ProxyingHandlerMethodArgumentResolver into the target factory.

Author: odrotbohm

src/main/java/org/springframework/data/projection/ProxyProjectionFactory.java

@@ -27,7 +27,10 @@
 import org.springframework.aop.framework.Advised;
 import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.beans.BeanUtils;
+import org.springframework.context.ResourceLoaderAware;
+import org.springframework.core.io.ResourceLoader;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 
 /**
  * A {@link ProjectionFactory} to create JDK proxies to back interfaces and handle method invocations on them. By
@@ -39,11 +42,22 @@
  * @see SpelAwareProxyProjectionFactory
  * @since 1.10
  */
-class ProxyProjectionFactory implements ProjectionFactory {
+class ProxyProjectionFactory implements ProjectionFactory, ResourceLoaderAware {
 
 	private static final boolean IS_JAVA_8 = org.springframework.util.ClassUtils.isPresent("java.util.Optional",
 			ProxyProjectionFactory.class.getClassLoader());
 
+	private ResourceLoader resourceLoader;
+
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.context.ResourceLoaderAware#setResourceLoader(org.springframework.core.io.ResourceLoader)
+	 */
+	@Override
+	public void setResourceLoader(ResourceLoader resourceLoader) {
+		this.resourceLoader = resourceLoader;
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.data.rest.core.projection.ProjectionFactory#createProjection(java.lang.Object, java.lang.Class)
@@ -71,7 +85,8 @@ public <T> T createProjection(Class<T> projectionType, Object source) {
 		factory.addAdvice(new TargetAwareMethodInterceptor(source.getClass()));
 		factory.addAdvice(getMethodInterceptor(source, projectionType));
 
-		return (T) factory.getProxy(getClass().getClassLoader());
+		return (T) factory
+				.getProxy(resourceLoader == null ? ClassUtils.getDefaultClassLoader() : resourceLoader.getClassLoader());
 	}
 
 	/* 
@@ -141,7 +156,7 @@ protected MethodInterceptor postProcessAccessorInterceptor(MethodInterceptor int
 	/**
 	 * Returns whether the given {@link PropertyDescriptor} describes an input property for the projection, i.e. a
 	 * property that needs to be present on the source to be able to create reasonable projections for the type the
-	 * descritor was looked up on.
+	 * descriptor was looked up on.
 	 * 
 	 * @param descriptor will never be {@literal null}.
 	 * @return

src/main/java/org/springframework/data/web/ProxyingHandlerMethodArgumentResolver.java

@@ -19,8 +19,10 @@
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.context.ResourceLoaderAware;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.convert.ConversionService;
+import org.springframework.core.io.ResourceLoader;
 import org.springframework.data.projection.SpelAwareProxyProjectionFactory;
 import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.bind.support.WebDataBinderFactory;
@@ -34,7 +36,8 @@
  * @author Oliver Gierke
  * @since 1.10
  */
-public class ProxyingHandlerMethodArgumentResolver extends ModelAttributeMethodProcessor implements BeanFactoryAware {
+public class ProxyingHandlerMethodArgumentResolver extends ModelAttributeMethodProcessor
+		implements BeanFactoryAware, ResourceLoaderAware {
 
 	private final SpelAwareProxyProjectionFactory proxyFactory;
 	private final ConversionService conversionService;
@@ -61,6 +64,15 @@ public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
 		this.proxyFactory.setBeanFactory(beanFactory);
 	}
 
+	/* 
+	 * (non-Javadoc)
+	 * @see org.springframework.context.ResourceLoaderAware#setResourceLoader(org.springframework.core.io.ResourceLoader)
+	 */
+	@Override
+	public void setResourceLoader(ResourceLoader resourceLoader) {
+		this.proxyFactory.setResourceLoader(resourceLoader);
+	}
+
 	/* 
 	 * (non-Javadoc)
 	 * @see org.springframework.web.method.support.HandlerMethodArgumentResolver#supportsParameter(org.springframework.core.MethodParameter)

src/main/java/org/springframework/data/web/config/SpringDataWebConfiguration.java

@@ -97,6 +97,11 @@ public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentRes
 		argumentResolvers.add(sortResolver());
 		argumentResolvers.add(pageableResolver());
 
-		argumentResolvers.add(new ProxyingHandlerMethodArgumentResolver(conversionService.getObject()));
+		ProxyingHandlerMethodArgumentResolver resolver = new ProxyingHandlerMethodArgumentResolver(
+				conversionService.getObject());
+		resolver.setBeanFactory(context);
+		resolver.setResourceLoader(context);
+
+		argumentResolvers.add(resolver);
 	}
 }