GH-10083: Apply Nullability to GraphQL module (#10260)

Related to: #10083

* Add `@SuppressWarnings("NullAway")` to the function where we get a message id,
which technically is never null in Spring Integration

Author: artembilan

spring-integration-graphql/src/main/java/org/springframework/integration/graphql/dsl/package-info.java

@@ -1,6 +1,5 @@
 /**
  * Provides classes for Java DSL to support GraphQL components.
  */
-@org.springframework.lang.NonNullApi
-@org.springframework.lang.NonNullFields
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.graphql.dsl;

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

@@ -19,6 +19,8 @@
 import java.util.Locale;
 import java.util.Map;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.expression.Expression;
 import org.springframework.expression.common.LiteralExpression;
@@ -30,7 +32,6 @@
 import org.springframework.integration.expression.FunctionExpression;
 import org.springframework.integration.expression.SupplierExpression;
 import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
-import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
 
@@ -49,16 +50,15 @@ public class GraphQlMessageHandler extends AbstractReplyProducingMessageHandler
 
 	private StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
 
-	@Nullable
-	private Expression operationExpression;
+	private @Nullable Expression operationExpression;
 
 	private Expression operationNameExpression = new SupplierExpression<>(() -> null);
 
 	private Expression variablesExpression = new SupplierExpression<>(() -> null);
 
-	@Nullable
-	private Locale locale;
+	private @Nullable Locale locale;
 
+	@SuppressWarnings("NullAway") // In most cases the message really comes with an ID
 	private Expression executionIdExpression =
 			new FunctionExpression<Message<?>>(message -> message.getHeaders().getId());
 
@@ -163,19 +163,16 @@ private String evaluateOperationExpression(Message<?> message) {
 		return operation;
 	}
 
-	@Nullable
-	private String evaluateOperationNameExpression(Message<?> message) {
+	private @Nullable String evaluateOperationNameExpression(Message<?> message) {
 		return this.operationNameExpression.getValue(this.evaluationContext, message, String.class);
 	}
 
-	@Nullable
 	@SuppressWarnings("unchecked")
-	private Map<String, Object> evaluateVariablesExpression(Message<?> message) {
+	private @Nullable Map<String, Object> evaluateVariablesExpression(Message<?> message) {
 		return this.variablesExpression.getValue(this.evaluationContext, message, Map.class);
 	}
 
-	@Nullable
-	private String evaluateExecutionIdExpression(Message<?> message) {
+	private @Nullable String evaluateExecutionIdExpression(Message<?> message) {
 		return this.executionIdExpression.getValue(this.evaluationContext, message, String.class);
 	}
 

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

@@ -1,6 +1,5 @@
 /**
  * Provides classes for GraphQL outbound channel adapters.
  */
-@org.springframework.lang.NonNullApi
-@org.springframework.lang.NonNullFields
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.graphql.outbound;