Scan for exception handlers using beans instead of classloader; fix #171

Author: oliemansm

example-graphql-tools/src/main/resources/application.yml

@@ -3,6 +3,17 @@ spring:
     name: graphql-java-tools-app
 server:
   port: 9001
+graphql:
+  servlet:
+    exception-handlers-enabled: true
 graphiql:
   headers:
     Authorization: "Bearer 05bd9a5f3fe0408f89520946b0fe1b06"
+logging:
+  level:
+    com:
+      oembedler:
+        moon:
+          graphql:
+            boot:
+              error: debug

gradle.properties

@@ -17,7 +17,7 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #
 
-version = 5.4
+version = 5.4.1-SNAPSHOT
 PROJECT_GROUP = com.graphql-java-kickstart
 PROJECT_NAME = graphql-spring-boot
 PROJECT_DESC = GraphQL Spring Framework Boot

graphql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.java

@@ -21,6 +21,7 @@
 
 import com.fasterxml.jackson.databind.InjectableValues;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.oembedler.moon.graphql.boot.error.ErrorHandlerSupplier;
 import com.oembedler.moon.graphql.boot.error.GraphQLErrorHandlerFactory;
 import com.oembedler.moon.graphql.boot.metrics.MetricsInstrumentation;
 import graphql.execution.AsyncExecutionStrategy;
@@ -30,9 +31,12 @@
 import graphql.execution.preparsed.PreparsedDocumentProvider;
 import graphql.schema.GraphQLSchema;
 import graphql.servlet.*;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.*;
 import org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration;
@@ -48,6 +52,7 @@
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.config.annotation.CorsRegistryWorkaround;
 
+import javax.annotation.PostConstruct;
 import javax.servlet.MultipartConfigElement;
 import java.util.Collections;
 import java.util.List;
@@ -60,6 +65,7 @@
 /**
  * @author <a href="mailto:java.lang.RuntimeException@gmail.com">oEmbedler Inc.</a>
  */
+@Slf4j
 @Configuration
 @ConditionalOnWebApplication
 @ConditionalOnClass(DispatcherServlet.class)
@@ -85,6 +91,8 @@ public class GraphQLWebAutoConfiguration implements ApplicationContextAware {
     @Autowired(required = false)
     private GraphQLErrorHandler errorHandler;
 
+    private ErrorHandlerSupplier errorHandlerSupplier = new ErrorHandlerSupplier(null);
+
     @Autowired(required = false)
     private Map<String, ExecutionStrategy> executionStrategies;
 
@@ -110,6 +118,7 @@ public void setApplicationContext(ApplicationContext applicationContext) throws
             errorHandler = new GraphQLErrorHandlerFactory().create(context, graphQLServletProperties.isExceptionHandlersEnabled());
             context.getBeanFactory().registerSingleton(errorHandler.getClass().getCanonicalName(), errorHandler);
         }
+        errorHandlerSupplier.setErrorHandler(errorHandler);
     }
 
     @Bean
@@ -203,9 +212,7 @@ public GraphQLQueryInvoker queryInvoker(ExecutionStrategyProvider executionStrat
     public GraphQLObjectMapper graphQLObjectMapper(ObjectProvider<ObjectMapperProvider> objectMapperProviderObjectProvider) {
         GraphQLObjectMapper.Builder builder = newBuilder();
 
-        if (errorHandler != null) {
-            builder.withGraphQLErrorHandler(errorHandler);
-        }
+        builder.withGraphQLErrorHandler(errorHandlerSupplier);
 
         ObjectMapperProvider objectMapperProvider = objectMapperProviderObjectProvider.getIfAvailable();
 
@@ -214,7 +221,7 @@ public GraphQLObjectMapper graphQLObjectMapper(ObjectProvider<ObjectMapperProvid
         } else if (objectMapperConfigurer != null) {
             builder.withObjectMapperConfigurer(objectMapperConfigurer);
         }
-
+        log.info("Building GraphQLObjectMapper including errorHandler: {}", errorHandler);
         return builder.build();
     }
 

graphql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphql/boot/error/ErrorHandlerSupplier.java

@@ -0,0 +1,25 @@
+package com.oembedler.moon.graphql.boot.error;
+
+import graphql.servlet.GraphQLErrorHandler;
+
+import java.util.Objects;
+import java.util.function.Supplier;
+
+public class ErrorHandlerSupplier implements Supplier<GraphQLErrorHandler> {
+
+    private GraphQLErrorHandler errorHandler;
+
+    public ErrorHandlerSupplier(GraphQLErrorHandler errorHandler) {
+        this.errorHandler = errorHandler;
+    }
+
+    @Override
+    public GraphQLErrorHandler get() {
+        return errorHandler;
+    }
+
+    public void setErrorHandler(GraphQLErrorHandler errorHandler) {
+        this.errorHandler = Objects.requireNonNull(errorHandler);
+    }
+
+}

graphql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphql/boot/error/GraphQLErrorFromExceptionHandler.java

@@ -6,13 +6,15 @@
 import graphql.SerializationError;
 import graphql.servlet.DefaultGraphQLErrorHandler;
 import graphql.servlet.GenericGraphQLError;
+import lombok.extern.slf4j.Slf4j;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
+@Slf4j
 class GraphQLErrorFromExceptionHandler extends DefaultGraphQLErrorHandler {
 
     private List<GraphQLErrorFactory> factories;

graphql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphql/boot/error/GraphQLErrorHandlerFactory.java

@@ -4,7 +4,7 @@
 import graphql.servlet.DefaultGraphQLErrorHandler;
 import graphql.servlet.GraphQLErrorHandler;
 import lombok.extern.slf4j.Slf4j;
-import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
@@ -14,7 +14,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Objects;
 import java.util.stream.Collectors;
 
 @Slf4j
@@ -24,29 +23,28 @@ public GraphQLErrorHandler create(ConfigurableApplicationContext applicationCont
         ConfigurableListableBeanFactory beanFactory = applicationContext.getBeanFactory();
         List<GraphQLErrorFactory> factories = Arrays.stream(beanFactory.getBeanDefinitionNames())
                 .filter(applicationContext::containsBean)
-                .map(beanFactory::getBeanDefinition)
-                .map(BeanDefinition::getBeanClassName)
-                .filter(Objects::nonNull)
-                .map(name -> scanForExceptionHandlers(applicationContext, beanFactory, name))
+                .map(name -> scanForExceptionHandlers(applicationContext, name))
                 .flatMap(List::stream)
                 .collect(Collectors.toList());
 
         if (!factories.isEmpty() || exceptionHandlersEnabled) {
+            log.debug("Handle GraphQL errors using exception handlers defined in {} custom factories", factories.size());
             return new GraphQLErrorFromExceptionHandler(factories);
         }
 
+        log.debug("Using default GraphQL error handler");
         return new DefaultGraphQLErrorHandler();
     }
 
-    private List<GraphQLErrorFactory> scanForExceptionHandlers(ApplicationContext context, ConfigurableListableBeanFactory beanFactory, String className) {
+    private List<GraphQLErrorFactory> scanForExceptionHandlers(ApplicationContext context, String name) {
         try {
-            Class<?> objClz = beanFactory.getBeanClassLoader().loadClass(className);
+            Class<?> objClz = context.getBean(name).getClass();
             return Arrays.stream(objClz.getDeclaredMethods())
                     .filter(this::isGraphQLExceptionHandlerMethod)
-                    .map(method -> GraphQLErrorFactory.withReflection(context.getBean(className), method))
+                    .map(method -> GraphQLErrorFactory.withReflection(context.getBean(name), method))
                     .collect(Collectors.toList());
-        } catch (ClassNotFoundException e) {
-            log.error("Cannot load class " + className + ". " + e.getMessage());
+        } catch (BeanCreationException e) {
+            log.error("Cannot load class " + name + ". " + e.getMessage());
             return Collections.emptyList();
         }
     }