implement requested changes

issue spring-projects#3501

Author: dmfrey

spring-integration-graphql/src/main/java/org/springframework/integration/graphql/outbound/GraphQlMessageHandler.java

@@ -19,6 +19,7 @@
 import java.util.Collections;
 import java.util.Map;
 
+import org.springframework.beans.factory.BeanFactory;
 import org.springframework.expression.Expression;
 import org.springframework.expression.common.LiteralExpression;
 import org.springframework.expression.spel.support.StandardEvaluationContext;
@@ -30,8 +31,6 @@
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
 
-import graphql.com.google.common.base.Strings;
-
 /**
  * A {@link org.springframework.messaging.MessageHandler} capable of fielding GraphQL Query, Mutation and Subscription requests.
  *
@@ -53,7 +52,6 @@ public class GraphQlMessageHandler extends AbstractReplyProducingMessageHandler
 	public GraphQlMessageHandler(final GraphQlService graphQlService) {
 		Assert.notNull(graphQlService, "'graphQlService' must not be null");
 
-		this.evaluationContext = ExpressionUtils.createStandardEvaluationContext(getBeanFactory());
 		this.graphQlService = graphQlService;
 		setAsync(true);
 	}
@@ -92,14 +90,6 @@ public void setOperationNameExpression(Expression operationNameExpression) {
 		this.operationNameExpression = operationNameExpression;
 	}
 
-	/**
-	 * Specify variables for the GraphQL Query to execute.
-	 * @param variables the GraphQL variables to use.
-	 */
-	public void setVariables(Map<String, Object> variables) {
-		setVariablesExpression(new SupplierExpression<>(() -> variables));
-	}
-
 	/**
 	 * Set a SpEL expression to evaluate Variables for GraphQL Query to execute.
 	 * @param variablesExpression the expression to use.
@@ -109,6 +99,12 @@ public void setVariablesExpression(Expression variablesExpression) {
 		this.variablesExpression = variablesExpression;
 	}
 
+	@Override
+	protected final void doInit() {
+		BeanFactory beanFactory = getBeanFactory();
+		this.evaluationContext = ExpressionUtils.createStandardEvaluationContext(beanFactory);
+	}
+
 	@Override
 	protected Object handleRequestMessage(Message<?> requestMessage) {
 
@@ -117,16 +113,14 @@ protected Object handleRequestMessage(Message<?> requestMessage) {
 			return this.graphQlService
 					.execute((RequestInput) requestMessage.getPayload());
 		}
-		else if (requestMessage.getPayload() instanceof String && !Strings.isNullOrEmpty((String) requestMessage.getPayload())) {
+		else  {
+			Assert.notNull(this.queryExpression, "'queryExpression' must not be null");
 			String query = evaluateQueryExpression(requestMessage);
 			String operationName = evaluateOperationNameExpression(requestMessage);
 			Map<String, Object> variables = evaluateVariablesExpression(requestMessage);
 			return this.graphQlService
 					.execute(new RequestInput(query, operationName, variables));
 		}
-		else {
-			throw new IllegalArgumentException("Message payload does not meet criteria to construct a 'org.springframework.graphql.RequestInput'");
-		}
 	}
 
 	private String evaluateQueryExpression(Message<?> message) {

spring-integration-graphql/src/test/java/org/springframework/integration/graphql/outbound/GraphQlMessageHandlerTests.java

@@ -45,6 +45,7 @@
 import org.springframework.integration.dsl.IntegrationFlow;
 import org.springframework.integration.dsl.IntegrationFlows;
 import org.springframework.integration.dsl.MessageChannels;
+import org.springframework.integration.expression.FunctionExpression;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHandlingException;
 import org.springframework.messaging.PollableChannel;
@@ -161,7 +162,7 @@ void testHandleMessageForQueryWithQueryAndOperationNameAndVariablesProvided() {
 		String fakeQuery = "query FriendlyName($id: String) { testQueryById(id: $id) { id } }";
 		this.graphQlMessageHandler.setQuery(fakeQuery);
 		this.graphQlMessageHandler.setOperationName("FriendlyName");
-		this.graphQlMessageHandler.setVariables(Map.of("$id", "test-data"));
+		this.graphQlMessageHandler.setVariablesExpression(new FunctionExpression<>(m -> Map.of("$id", "test-data")));
 
 		StepVerifier.create(
 						Mono.from((Mono<ExecutionResult>) this.graphQlMessageHandler.handleRequestMessage(MessageBuilder.withPayload(fakeQuery).build()))
@@ -267,15 +268,13 @@ void testHandleMessageForQueryWithInvalidPayload() {
 				.isInstanceOf(MessageHandlingException.class)
 				.satisfies((ex) -> assertThat((Exception) ex)
 						.hasMessageContaining(
-								"Message payload does not meet criteria to construct a 'org.springframework.graphql.RequestInput'"));
+								"'queryExpression' must not be null"));
 
 	}
 
 	@Test
 	void testHandleMessageForMutationWithInvalidPayload() {
 
-		String fakeId = UUID.randomUUID().toString();
-
 		this.inputChannel.send(
 				MessageBuilder
 						.withPayload(new Object())
@@ -289,7 +288,7 @@ void testHandleMessageForMutationWithInvalidPayload() {
 				.isInstanceOf(MessageHandlingException.class)
 				.satisfies((ex) -> assertThat((Exception) ex)
 						.hasMessageContaining(
-								"Message payload does not meet criteria to construct a 'org.springframework.graphql.RequestInput'"));
+								"'queryExpression' must not be null"));
 
 	}
 
@@ -309,7 +308,7 @@ void testHandleMessageForSubscriptionWithInvalidPayload() {
 				.isInstanceOf(MessageHandlingException.class)
 				.satisfies((ex) -> assertThat((Exception) ex)
 						.hasMessageContaining(
-								"Message payload does not meet criteria to construct a 'org.springframework.graphql.RequestInput'"));
+								"'queryExpression' must not be null"));
 
 	}