Extract InvocableHandlerMethodSupport

This prepares the way to invoke handler methods other than those
adapted to a DataFetcher with DataFetcherEnvironment as input.

See gh-130

spring-graphql/src/main/java/org/springframework/graphql/data/method/DataFetcherHandlerMethod.java

@@ -15,30 +15,26 @@
  */
 package org.springframework.graphql.data.method;
 
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.Arrays;
 
 import graphql.schema.DataFetchingEnvironment;
 
-import org.springframework.core.CoroutinesUtils;
 import org.springframework.core.DefaultParameterNameDiscoverer;
-import org.springframework.core.KotlinDetector;
 import org.springframework.core.MethodParameter;
 import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
-import org.springframework.util.ReflectionUtils;
 
 /**
- * Extension of {@link HandlerMethod} that can resolve method arguments from a
- * {@link DataFetchingEnvironment} and invoke the method.
+ * An extension of {@link HandlerMethod} for annotated handler methods adapted
+ * to {@link graphql.schema.DataFetcher} with {@link DataFetchingEnvironment}
+ * as their input.
  *
  * @author Rossen Stoyanchev
  * @since 1.0.0
  */
-public class InvocableHandlerMethod extends HandlerMethod {
+public class DataFetcherHandlerMethod extends InvocableHandlerMethodSupport {
 
 	private static final Object[] EMPTY_ARGS = new Object[0];
 
@@ -48,7 +44,7 @@ public class InvocableHandlerMethod extends HandlerMethod {
 	private final ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
 
 
-	public InvocableHandlerMethod(HandlerMethod handlerMethod, HandlerMethodArgumentResolverComposite resolvers) {
+	public DataFetcherHandlerMethod(HandlerMethod handlerMethod, HandlerMethodArgumentResolverComposite resolvers) {
 		super(handlerMethod);
 		Assert.isTrue(!resolvers.getResolvers().isEmpty(), "No argument resolvers");
 		this.resolvers = resolvers;
@@ -127,40 +123,4 @@ public class InvocableHandlerMethod extends HandlerMethod {
 		return args;
 	}
 
-	/**
-	 * Invoke the handler method with the given argument values.
-	 */
-	@Nullable
-	protected Object doInvoke(Object... args) throws Exception {
-		Method method = getBridgedMethod();
-		ReflectionUtils.makeAccessible(method);
-		try {
-			if (KotlinDetector.isSuspendingFunction(method)) {
-				return CoroutinesUtils.invokeSuspendingFunction(method, getBean(), args);
-			}
-			return method.invoke(getBean(), args);
-		}
-		catch (IllegalArgumentException ex) {
-			assertTargetBean(method, getBean(), args);
-			String text = (ex.getMessage() != null ? ex.getMessage() : "Illegal argument");
-			throw new IllegalStateException(formatInvokeError(text, args), ex);
-		}
-		catch (InvocationTargetException ex) {
-			// Unwrap for DataFetcherExceptionResolvers ...
-			Throwable targetException = ex.getTargetException();
-			if (targetException instanceof RuntimeException) {
-				throw (RuntimeException) targetException;
-			}
-			else if (targetException instanceof Error) {
-				throw (Error) targetException;
-			}
-			else if (targetException instanceof Exception) {
-				throw (Exception) targetException;
-			}
-			else {
-				throw new IllegalStateException(formatInvokeError("Invocation failure", args), targetException);
-			}
-		}
-	}
-
 }

spring-graphql/src/main/java/org/springframework/graphql/data/method/HandlerMethod.java

@@ -32,6 +32,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -78,6 +79,7 @@ public class HandlerMethod {
 		this.beanType = ClassUtils.getUserClass(bean);
 		this.method = method;
 		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
+		ReflectionUtils.makeAccessible(this.bridgedMethod);
 		this.parameters = initMethodParameters();
 	}
 
@@ -100,6 +102,7 @@ public class HandlerMethod {
 		this.beanType = ClassUtils.getUserClass(beanType);
 		this.method = method;
 		this.bridgedMethod = BridgeMethodResolver.findBridgedMethod(method);
+		ReflectionUtils.makeAccessible(this.bridgedMethod);
 		this.parameters = initMethodParameters();
 	}
 

spring-graphql/src/main/java/org/springframework/graphql/data/method/InvocableHandlerMethodSupport.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2002-2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.graphql.data.method;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.springframework.core.CoroutinesUtils;
+import org.springframework.core.KotlinDetector;
+import org.springframework.lang.Nullable;
+
+/**
+ * Extension of {@link HandlerMethod} that adds support for invoking the
+ * annotated handler methods.
+ *
+ * @author Rossen Stoyanchev
+ * @since 1.0.0
+ */
+public abstract class InvocableHandlerMethodSupport extends HandlerMethod {
+
+
+	protected InvocableHandlerMethodSupport(HandlerMethod handlerMethod) {
+		super(handlerMethod.createWithResolvedBean());
+	}
+
+
+	/**
+	 * Invoke the handler method with the given argument values.
+	 */
+	@Nullable
+	protected Object doInvoke(Object... args) throws Exception {
+		Method method = getBridgedMethod();
+		try {
+			if (KotlinDetector.isSuspendingFunction(method)) {
+				return CoroutinesUtils.invokeSuspendingFunction(method, getBean(), args);
+			}
+			return method.invoke(getBean(), args);
+		}
+		catch (IllegalArgumentException ex) {
+			assertTargetBean(method, getBean(), args);
+			String text = (ex.getMessage() != null ? ex.getMessage() : "Illegal argument");
+			throw new IllegalStateException(formatInvokeError(text, args), ex);
+		}
+		catch (InvocationTargetException ex) {
+			// Unwrap for DataFetcherExceptionResolvers ...
+			Throwable targetException = ex.getTargetException();
+			if (targetException instanceof RuntimeException) {
+				throw (RuntimeException) targetException;
+			}
+			else if (targetException instanceof Error) {
+				throw (Error) targetException;
+			}
+			else if (targetException instanceof Exception) {
+				throw (Exception) targetException;
+			}
+			else {
+				throw new IllegalStateException(formatInvokeError("Invocation failure", args), targetException);
+			}
+		}
+	}
+
+}