replace executionId with idExpression SpEL evaluator

issue spring-projects#3501

Author: dmfrey

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

@@ -19,6 +19,8 @@
 import java.util.Collections;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Objects;
+import java.util.UUID;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.expression.Expression;
@@ -31,6 +33,7 @@
 import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
 import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
 import org.springframework.util.Assert;
 
 /**
@@ -54,7 +57,7 @@ public class GraphQlMessageHandler extends AbstractReplyProducingMessageHandler
 	@Nullable
 	private Locale locale;
 
-	private String executionId = null;
+	private Expression idExpression = new SupplierExpression<>(() -> null);
 
 	public GraphQlMessageHandler(final GraphQlService graphQlService) {
 		Assert.notNull(graphQlService, "'graphQlService' must not be null");
@@ -116,12 +119,12 @@ public void setLocale(@Nullable Locale locale) {
 	}
 
 	/**
-	 * Set a Execution Id for GraphQL Operation to execute.
-	 * @param executionId the executionId to use.
+	 * Set a SpEL expression to evaluate Id for GraphQL Operation Request to execute.
+	 * @param idExpression the idExpression to use.
 	 */
-	public void setExecutionId(String executionId) {
-		Assert.hasText(executionId, "'executionId' must not be empty");
-		this.executionId = executionId;
+	public void setIdExpression(Expression idExpression) {
+		Assert.notNull(idExpression, "'idExpression' must not be null");
+		this.idExpression = idExpression;
 	}
 
 	@Override
@@ -140,11 +143,12 @@ protected Object handleRequestMessage(Message<?> requestMessage) {
 		}
 		else  {
 			Assert.notNull(this.operationExpression, "'operationExpression' must not be null");
-//			Assert.hasText(this.executionId, "'executionId' must not be empty");
+			Assert.notNull(this.idExpression, "'idExpression' must not be null");
 			String query = evaluateOperationExpression(requestMessage);
 			String operationName = evaluateOperationNameExpression(requestMessage);
 			Map<String, Object> variables = evaluateVariablesExpression(requestMessage);
-			requestInput = new RequestInput(query, operationName, variables, this.locale, this.executionId);
+			String id = evaluateIdExpression(requestMessage);
+			requestInput = new RequestInput(query, operationName, variables, this.locale, id);
 		}
 
 		return this.graphQlService
@@ -167,4 +171,13 @@ private Map<String, Object> evaluateVariablesExpression(Message<?> message) {
 		return this.variablesExpression.getValue(this.evaluationContext, message, Map.class);
 	}
 
+	private String evaluateIdExpression(Message<?> message) {
+		String id = this.idExpression.getValue(this.evaluationContext, message, String.class);
+		if (id == null) {
+			return Objects.requireNonNull(message.getHeaders().get(MessageHeaders.ID)).toString();
+		}
+
+		return id;
+	}
+
 }

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

@@ -22,7 +22,6 @@
 import java.util.Collections;
 import java.util.Locale;
 import java.util.Map;
-import java.util.Objects;
 import java.util.UUID;
 
 import org.junit.jupiter.api.Test;
@@ -56,8 +55,6 @@
 import org.springframework.stereotype.Repository;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
-import org.springframework.util.AlternativeJdkIdGenerator;
-import org.springframework.util.IdGenerator;
 
 import graphql.execution.reactive.SubscriptionPublisher;
 import reactor.core.publisher.Flux;
@@ -125,9 +122,6 @@ void testHandleMessageForQueryWithQueryProvided() {
 		Locale locale = Locale.getDefault();
 		this.graphQlMessageHandler.setLocale(locale);
 
-		String executionId = UUID.randomUUID().toString();
-		this.graphQlMessageHandler.setExecutionId(executionId);
-
 		StepVerifier.create(
 				Mono.from((Mono<RequestOutput>) this.graphQlMessageHandler.handleRequestMessage(MessageBuilder.withPayload(fakeQuery).build()))
 		)