DATAMONGO-2547 - Use target class ClassLoader instead of default CL when creating proxy instances.

Original pull request: #865.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoDatabaseFactorySupport.java

@@ -257,7 +257,7 @@ public abstract class MongoDatabaseFactorySupport<C> implements MongoDatabaseFac
 			factory.addAdvice(new SessionAwareMethodInterceptor<>(session, target, ClientSession.class, MongoDatabase.class,
 					this::proxyDatabase, MongoCollection.class, this::proxyCollection));
 
-			return targetType.cast(factory.getProxy());
+			return targetType.cast(factory.getProxy(target.getClass().getClassLoader()));
 		}
 
 		public ClientSession getSession() {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/SimpleReactiveMongoDatabaseFactory.java

@@ -271,7 +271,7 @@ public class SimpleReactiveMongoDatabaseFactory implements DisposableBean, React
 			factory.addAdvice(new SessionAwareMethodInterceptor<>(session, target, ClientSession.class, MongoDatabase.class,
 					this::proxyDatabase, MongoCollection.class, this::proxyCollection));
 
-			return targetType.cast(factory.getProxy());
+			return targetType.cast(factory.getProxy(target.getClass().getClassLoader()));
 		}
 
 		public ClientSession getSession() {

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/DefaultDbRefResolver.java

@@ -202,7 +202,7 @@ public class DefaultDbRefResolver implements DbRefResolver {
 		proxyFactory.addInterface(propertyType);
 		proxyFactory.addAdvice(interceptor);
 
-		return handler.populateId(property, dbref, proxyFactory.getProxy());
+		return handler.populateId(property, dbref, proxyFactory.getProxy(LazyLoadingProxy.class.getClassLoader()));
 	}
 
 	/**

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/repository/query/QueryUtils.java

@@ -61,7 +61,7 @@ class QueryUtils {
 			return combinedSort;
 		});
 
-		return (Query) factory.getProxy();
+		return (Query) factory.getProxy(query.getClass().getClassLoader());
 	}
 
 	/**