refactor to handle GraphQL Subscription requests

issue spring-projects#3501

Author: dmfrey

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2022 the original author or authors.
+ * Copyright 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.
@@ -16,155 +16,40 @@
 
 package org.springframework.integration.graphql.outbound;
 
-import java.util.Collections;
-import java.util.Locale;
-import java.util.Map;
-
-import javax.annotation.Nullable;
-
-import org.springframework.beans.factory.BeanFactory;
-import org.springframework.expression.Expression;
-import org.springframework.expression.common.LiteralExpression;
-import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.graphql.GraphQlService;
 import org.springframework.graphql.RequestInput;
-import org.springframework.integration.expression.ExpressionUtils;
-import org.springframework.integration.expression.SupplierExpression;
 import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
 import org.springframework.messaging.Message;
-import org.springframework.util.Assert;
+
+import graphql.ExecutionResult;
+import reactor.core.publisher.Mono;
 
 /**
- * A {@link org.springframework.messaging.MessageHandler} capable of fielding GraphQL Query, Mutation and Subscription requests.
+ * A <code>MessageHandler</code> capable of fielding GraphQL Query, Mutation and Subscription requests.
  *
  * @author Daniel Frey
- * @since 6.0
  */
 public class GraphQlMessageHandler extends AbstractReplyProducingMessageHandler {
 
 	private final GraphQlService graphQlService;
 
-	private StandardEvaluationContext evaluationContext;
-
-	private Expression queryExpression;
-
-	private Expression operationNameExpression = new SupplierExpression<>(() -> null);
-
-	private Expression variablesExpression = new SupplierExpression<>(() -> Collections.emptyMap());
-
-	private Locale locale = null;
-
-	private String executionId = null;
-
 	public GraphQlMessageHandler(final GraphQlService graphQlService) {
-		Assert.notNull(graphQlService, "'graphQlService' must not be null");
-
 		this.graphQlService = graphQlService;
 		setAsync(true);
 	}
 
-	/**
-	 * Specify a GraphQL Query.
-	 * @param query the GraphQL query to use.
-	 */
-	public void setQuery(String query) {
-		Assert.hasText(query, "'query' must not be empty");
-		setQueryExpression(new LiteralExpression(query));
-	}
-
-	/**
-	 * Specify a SpEL expression to evaluate a GraphQL Query
-	 * @param queryExpression the expression to evaluate a GraphQL query.
-	 */
-	public void setQueryExpression(Expression queryExpression) {
-		Assert.notNull(queryExpression, "'queryExpression' must not be null");
-		this.queryExpression = queryExpression;
-	}
-
-	/**
-	 * Set a GraphQL Operation Name to execute.
-	 * @param operationName the GraphQL Operation Name to use.
-	 */
-	public void setOperationName(String operationName) {
-		setOperationNameExpression(new LiteralExpression(operationName));
-	}
-
-	/**
-	 * Set a SpEL expression to evaluate a GraphQL Operation Name to execute.
-	 * @param operationNameExpression the expression to use.
-	 */
-	public void setOperationNameExpression(Expression operationNameExpression) {
-		Assert.notNull(operationNameExpression, "'operationNameExpression' must not be null");
-		this.operationNameExpression = operationNameExpression;
-	}
-
-	/**
-	 * Set a SpEL expression to evaluate Variables for GraphQL Query to execute.
-	 * @param variablesExpression the expression to use.
-	 */
-	public void setVariablesExpression(Expression variablesExpression) {
-		Assert.notNull(variablesExpression, "'variablesExpression' must not be null");
-		this.variablesExpression = variablesExpression;
-	}
-
-	/**
-	 * Set a Locale for GraphQL Query to execute.
-	 * @param locale the locale to use.
-	 */
-	public void setLocale(@Nullable Locale locale) {
-		this.locale = locale;
-	}
-
-	/**
-	 * Set a Execution Id for GraphQL Query to execute.
-	 * @param executionId the executionId to use.
-	 */
-	public void setExecutionId(String executionId) {
-		Assert.hasText(executionId, "'executionId' must not be empty");
-		this.executionId = executionId;
-	}
-
-	@Override
-	protected final void doInit() {
-		BeanFactory beanFactory = getBeanFactory();
-		this.evaluationContext = ExpressionUtils.createStandardEvaluationContext(beanFactory);
-	}
-
 	@Override
 	protected Object handleRequestMessage(Message<?> requestMessage) {
-		RequestInput requestInput = null;
 
 		if (requestMessage.getPayload() instanceof RequestInput) {
 
-			requestInput = (RequestInput) requestMessage.getPayload();
+			Mono<ExecutionResult> result = this.graphQlService
+					.execute((RequestInput) requestMessage.getPayload());
+
+			return result;
 		}
-		else  {
-			Assert.notNull(this.queryExpression, "'queryExpression' must not be null");
-			Assert.hasText(this.executionId, "'executionId' must not be empty");
-			String query = evaluateQueryExpression(requestMessage);
-			String operationName = evaluateOperationNameExpression(requestMessage);
-			Map<String, Object> variables = evaluateVariablesExpression(requestMessage);
-			requestInput = new RequestInput(query, operationName, variables, this.locale, this.executionId);
+		else {
+			throw new IllegalArgumentException("Message payload needs to be 'org.springframework.graphql.RequestInput'");
 		}
-
-		return this.graphQlService
-				.execute(requestInput);
-
 	}
-
-	private String evaluateQueryExpression(Message<?> message) {
-		String query = this.queryExpression.getValue(this.evaluationContext, message, String.class);
-		Assert.notNull(query, "'queryExpression' must not evaluate to null");
-		return query;
-	}
-
-	private String evaluateOperationNameExpression(Message<?> message) {
-		return this.operationNameExpression.getValue(this.evaluationContext, message, String.class);
-	}
-
-	@SuppressWarnings("unchecked")
-	private Map<String, Object> evaluateVariablesExpression(Message<?> message) {
-		return this.variablesExpression.getValue(this.evaluationContext, message, Map.class);
-	}
-
 }

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

@@ -66,9 +66,9 @@
  * @author Daniel Frey
  *
  */
-@SpringJUnitConfig(GraphqlMutationMessageHandlerTests.TestConfig.class)
+@SpringJUnitConfig(GraphQlMutationMessageHandlerTests.TestConfig.class)
 @DirtiesContext
-public class GraphqlMutationMessageHandlerTests {
+public class GraphQlMutationMessageHandlerTests {
 
 	@Autowired
 	private FluxMessageChannel inputChannel;
@@ -83,6 +83,7 @@ public class GraphqlMutationMessageHandlerTests {
 	UpdateRepository updateRepository;
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void testHandleMessageForMutation() {
 
 		String fakeId = UUID.randomUUID().toString();
@@ -179,13 +180,13 @@ Mono<Update> current() {
 	static class TestConfig {
 
 		@Bean
-		GraphqlQueryMutationMessageHandler handler(GraphQlService graphQlService) {
+		GraphQlMessageHandler handler(GraphQlService graphQlService) {
 
-			return new GraphqlQueryMutationMessageHandler(graphQlService);
+			return new GraphQlMessageHandler(graphQlService);
 		}
 
 		@Bean
-		IntegrationFlow graphqlQueryMessageHandlerFlow(GraphqlQueryMutationMessageHandler handler) {
+		IntegrationFlow graphqlQueryMessageHandlerFlow(GraphQlMessageHandler handler) {
 
 			return IntegrationFlows.from(MessageChannels.flux("inputChannel"))
 					.handle(handler)

spring-integration-graphql/src/test/java/org/springframework/integration/graphql/outbound/GraphqlMutationMessageHandlerTests.java renamed to spring-integration-graphql/src/test/java/org/springframework/integration/graphql/outbound/GraphQlMutationMessageHandlerTests.java

@@ -62,9 +62,9 @@
  * @author Daniel Frey
  *
  */
-@SpringJUnitConfig(GraphqlQueryMessageHandlerTests.TestConfig.class)
+@SpringJUnitConfig(GraphQlQueryMessageHandlerTests.TestConfig.class)
 @DirtiesContext
-public class GraphqlQueryMessageHandlerTests {
+public class GraphQlQueryMessageHandlerTests {
 
 	@Autowired
 	private FluxMessageChannel inputChannel;
@@ -76,6 +76,7 @@ public class GraphqlQueryMessageHandlerTests {
 	private PollableChannel errorChannel;
 
 	@Test
+	@SuppressWarnings("unchecked")
 	void testHandleMessageForQuery() {
 
 		StepVerifier verifier = StepVerifier.create(
@@ -137,13 +138,13 @@ public Mono<QueryResult> testQuery() {
 	static class TestConfig {
 
 		@Bean
-		GraphqlQueryMutationMessageHandler handler(GraphQlService graphQlService) {
+		GraphQlMessageHandler handler(GraphQlService graphQlService) {
 
-			return new GraphqlQueryMutationMessageHandler(graphQlService);
+			return new GraphQlMessageHandler(graphQlService);
 		}
 
 		@Bean
-		IntegrationFlow graphqlQueryMessageHandlerFlow(GraphqlQueryMutationMessageHandler handler) {
+		IntegrationFlow graphqlQueryMessageHandlerFlow(GraphQlMessageHandler handler) {
 
 			return IntegrationFlows.from(MessageChannels.flux("inputChannel"))
 					.handle(handler)