Apply Nullability to remaining spring-integration-ws module packages

* Add `@NullMarked` to all the `ws` packages
* Add `@Nullable` or `@SuppressWarnings("NullAway.Init")` whenever it is requested
* Add defensive null checks for better safety (`DefaultSoapHeaderMapper`, `SimpleWebServiceOutboundGateway`)

Signed-off-by: Jooyoung Pyoung <[email protected]>

Author: anthologia

spring-integration-ws/src/main/java/org/springframework/integration/ws/AbstractWebServiceOutboundGateway.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -25,6 +25,8 @@
 
 import javax.xml.transform.TransformerException;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.expression.Expression;
 import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.integration.expression.ExpressionEvalMap;
@@ -68,13 +70,14 @@ public abstract class AbstractWebServiceOutboundGateway extends AbstractReplyPro
 
 	private final String uri;
 
-	private final DestinationProvider destinationProvider;
+	private final @Nullable DestinationProvider destinationProvider;
 
 	private final Map<String, Expression> uriVariableExpressions = new HashMap<>();
 
+	@SuppressWarnings("NullAway.Init")
 	private StandardEvaluationContext evaluationContext;
 
-	private WebServiceMessageCallback requestCallback;
+	private @Nullable WebServiceMessageCallback requestCallback;
 
 	private WebServiceTemplate webServiceTemplate;
 
@@ -84,15 +87,17 @@ public abstract class AbstractWebServiceOutboundGateway extends AbstractReplyPro
 
 	private boolean webServiceTemplateExplicitlySet;
 
-	public AbstractWebServiceOutboundGateway(final String uri, WebServiceMessageFactory messageFactory) {
+	@SuppressWarnings("NullAway")
+	public AbstractWebServiceOutboundGateway(final String uri, @Nullable WebServiceMessageFactory messageFactory) {
 		Assert.hasText(uri, "URI must not be empty");
 		this.webServiceTemplate = new WebServiceTemplate(messageFactory);
 		this.destinationProvider = null;
 		this.uri = uri;
 	}
 
+	@SuppressWarnings("NullAway")
 	public AbstractWebServiceOutboundGateway(DestinationProvider destinationProvider,
-			WebServiceMessageFactory messageFactory) {
+			@Nullable WebServiceMessageFactory messageFactory) {
 
 		Assert.notNull(destinationProvider, "DestinationProvider must not be null");
 		this.webServiceTemplate = new WebServiceTemplate(messageFactory);
@@ -165,7 +170,7 @@ public void setMessageFactory(WebServiceMessageFactory messageFactory) {
 		this.webServiceTemplate.setMessageFactory(messageFactory);
 	}
 
-	public void setRequestCallback(WebServiceMessageCallback requestCallback) {
+	public void setRequestCallback(@Nullable WebServiceMessageCallback requestCallback) {
 		this.requestCallback = requestCallback;
 	}
 
@@ -199,7 +204,7 @@ protected WebServiceTemplate getWebServiceTemplate() {
 	}
 
 	@Override
-	public final Object handleRequestMessage(Message<?> requestMessage) {
+	public final @Nullable Object handleRequestMessage(Message<?> requestMessage) {
 		URI uriWithVariables = prepareUri(requestMessage);
 		if (uriWithVariables == null) {
 			throw new MessageDeliveryException(requestMessage, "Failed to determine URI for " +
@@ -215,7 +220,7 @@ public final Object handleRequestMessage(Message<?> requestMessage) {
 		return null;
 	}
 
-	private URI prepareUri(Message<?> requestMessage) {
+	private @Nullable URI prepareUri(Message<?> requestMessage) {
 		if (this.destinationProvider != null) {
 			return this.destinationProvider.getDestination();
 		}
@@ -229,17 +234,17 @@ private URI prepareUri(Message<?> requestMessage) {
 		return this.uriFactory.expand(this.uri, uriVariables);
 	}
 
-	protected abstract Object doHandle(String theUri, Message<?> requestMessage,
-			WebServiceMessageCallback reqCallback);
+	protected abstract @Nullable Object doHandle(String theUri, Message<?> requestMessage,
+			@Nullable WebServiceMessageCallback reqCallback);
 
 	protected abstract class RequestMessageCallback extends TransformerObjectSupport
 			implements WebServiceMessageCallback {
 
-		private final WebServiceMessageCallback reqCallback;
+		private final @Nullable WebServiceMessageCallback reqCallback;
 
 		private final Message<?> requestMessage;
 
-		public RequestMessageCallback(WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
+		public RequestMessageCallback(@Nullable WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
 			this.reqCallback = requestCallback;
 			this.requestMessage = requestMessage;
 		}
@@ -266,7 +271,7 @@ protected abstract class ResponseMessageExtractor extends TransformerObjectSuppo
 			implements WebServiceMessageExtractor<Object> {
 
 		@Override
-		public Object extractData(WebServiceMessage message)
+		public @Nullable Object extractData(WebServiceMessage message)
 				throws IOException, TransformerException {
 
 			Object resultObject = this.doExtractData(message);
@@ -284,7 +289,7 @@ public Object extractData(WebServiceMessage message)
 			}
 		}
 
-		public abstract Object doExtractData(WebServiceMessage message) throws IOException, TransformerException;
+		public abstract @Nullable Object doExtractData(WebServiceMessage message) throws IOException, TransformerException;
 
 	}
 

spring-integration-ws/src/main/java/org/springframework/integration/ws/DefaultSoapHeaderMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -53,6 +53,7 @@
  * @author Mauro Molinari
  * @author Artem Bilan
  * @author Gary Russell
+ * @author Jooyoung Pyoung
  *
  * @since 2.0
  */
@@ -126,6 +127,10 @@ else if (!StringUtils.hasText(target.getSoapAction())) {
 	@Override
 	protected void populateUserDefinedHeader(String headerName, Object headerValue, SoapMessage target) {
 		SoapHeader soapHeader = target.getSoapHeader();
+		if (soapHeader == null) {
+			return;
+		}
+
 		if (headerValue instanceof String) {
 			QName qname = QNameUtils.parseQNameString(headerName);
 			soapHeader.addAttribute(qname, (String) headerValue);

spring-integration-ws/src/main/java/org/springframework/integration/ws/MarshallingWebServiceInboundGateway.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -35,8 +35,10 @@
  */
 public class MarshallingWebServiceInboundGateway extends AbstractWebServiceInboundGateway {
 
+	@SuppressWarnings("NullAway.Init")
 	private Marshaller marshaller;
 
+	@SuppressWarnings("NullAway.Init")
 	private Unmarshaller unmarshaller;
 
 	/**

spring-integration-ws/src/main/java/org/springframework/integration/ws/MarshallingWebServiceOutboundGateway.java

@@ -46,11 +46,12 @@ public class MarshallingWebServiceOutboundGateway extends AbstractWebServiceOutb
 
 	@SuppressWarnings("this-escape")
 	public MarshallingWebServiceOutboundGateway(DestinationProvider destinationProvider, Marshaller marshaller,
-			Unmarshaller unmarshaller, WebServiceMessageFactory messageFactory) {
+			@Nullable Unmarshaller unmarshaller, @Nullable WebServiceMessageFactory messageFactory) {
 		super(destinationProvider, messageFactory);
 		configureMarshallers(marshaller, unmarshaller);
 	}
 
+	@SuppressWarnings("NullAway")
 	public MarshallingWebServiceOutboundGateway(DestinationProvider destinationProvider, Marshaller marshaller,
 			Unmarshaller unmarshaller) {
 		this(destinationProvider, marshaller, unmarshaller, null);
@@ -61,17 +62,19 @@ public MarshallingWebServiceOutboundGateway(DestinationProvider destinationProvi
 		this(destinationProvider, marshaller, null, messageFactory);
 	}
 
+	@SuppressWarnings("NullAway")
 	public MarshallingWebServiceOutboundGateway(DestinationProvider destinationProvider, Marshaller marshaller) {
 		this(destinationProvider, marshaller, (WebServiceMessageFactory) null);
 	}
 
 	@SuppressWarnings("this-escape")
-	public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller, Unmarshaller unmarshaller,
-			WebServiceMessageFactory messageFactory) {
+	public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller, @Nullable Unmarshaller unmarshaller,
+			@Nullable WebServiceMessageFactory messageFactory) {
 		super(uri, messageFactory);
 		configureMarshallers(marshaller, unmarshaller);
 	}
 
+	@SuppressWarnings("NullAway")
 	public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller, Unmarshaller unmarshaller) {
 		this(uri, marshaller, unmarshaller, null);
 	}
@@ -81,6 +84,7 @@ public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller,
 		this(uri, marshaller, null, messageFactory);
 	}
 
+	@SuppressWarnings("NullAway")
 	public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller) {
 		this(uri, marshaller, (WebServiceMessageFactory) null);
 	}
@@ -91,7 +95,7 @@ public MarshallingWebServiceOutboundGateway(String uri, Marshaller marshaller) {
 	 * @param webServiceTemplate the WebServiceTemplate
 	 * @since 5.0
 	 */
-	@SuppressWarnings("this-escape")
+	@SuppressWarnings({"this-escape", "NullAway"})
 	public MarshallingWebServiceOutboundGateway(String uri, WebServiceTemplate webServiceTemplate) {
 		super(uri, null);
 		doSetWebServiceTemplate(webServiceTemplate);
@@ -103,7 +107,7 @@ public MarshallingWebServiceOutboundGateway(String uri, WebServiceTemplate webSe
 	 * @param webServiceTemplate the WebServiceTemplate
 	 * @since 5.0
 	 */
-	@SuppressWarnings("this-escape")
+	@SuppressWarnings({"this-escape", "NullAway"})
 	public MarshallingWebServiceOutboundGateway(DestinationProvider destinationProvider,
 			WebServiceTemplate webServiceTemplate) {
 		super(destinationProvider, null);
@@ -140,15 +144,15 @@ public String getComponentType() {
 	}
 
 	@Override
-	protected Object doHandle(String uri, Message<?> requestMessage, WebServiceMessageCallback requestCallback) {
+	protected @Nullable Object doHandle(String uri, Message<?> requestMessage, @Nullable WebServiceMessageCallback requestCallback) {
 		return getWebServiceTemplate()
 				.marshalSendAndReceive(uri, requestMessage.getPayload(),
 						new PassThroughRequestMessageCallback(requestCallback, requestMessage));
 	}
 
 	private final class PassThroughRequestMessageCallback extends RequestMessageCallback {
 
-		PassThroughRequestMessageCallback(WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
+		PassThroughRequestMessageCallback(@Nullable WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
 			super(requestCallback, requestMessage);
 		}
 

spring-integration-ws/src/main/java/org/springframework/integration/ws/SimpleWebServiceOutboundGateway.java

@@ -49,6 +49,7 @@
  * @author Oleg Zhurakousky
  * @author Artem Bilan
  * @author Gary Russell
+ * @author Jooyoung Pyoung
  */
 public class SimpleWebServiceOutboundGateway extends AbstractWebServiceOutboundGateway {
 
@@ -68,7 +69,7 @@ public SimpleWebServiceOutboundGateway(DestinationProvider destinationProvider,
 
 	public SimpleWebServiceOutboundGateway(DestinationProvider destinationProvider,
 			@Nullable SourceExtractor<?> sourceExtractor,
-			WebServiceMessageFactory messageFactory) {
+			@Nullable WebServiceMessageFactory messageFactory) {
 
 		super(destinationProvider, messageFactory);
 		this.sourceExtractor = (sourceExtractor != null) ? sourceExtractor : new DefaultSourceExtractor();
@@ -83,7 +84,7 @@ public SimpleWebServiceOutboundGateway(String uri, SourceExtractor<?> sourceExtr
 	}
 
 	public SimpleWebServiceOutboundGateway(String uri, @Nullable SourceExtractor<?> sourceExtractor,
-			WebServiceMessageFactory messageFactory) {
+			@Nullable WebServiceMessageFactory messageFactory) {
 
 		super(uri, messageFactory);
 		this.sourceExtractor = (sourceExtractor != null) ? sourceExtractor : new DefaultSourceExtractor();
@@ -107,8 +108,8 @@ public String getComponentType() {
 	}
 
 	@Override
-	protected Object doHandle(String uri, final Message<?> requestMessage,
-			final WebServiceMessageCallback requestCallback) {
+	protected @Nullable Object doHandle(String uri, final Message<?> requestMessage,
+			final @Nullable WebServiceMessageCallback requestCallback) {
 
 		Object requestPayload = requestMessage.getPayload();
 		Result responseResultInstance = null;
@@ -126,21 +127,24 @@ else if (requestPayload instanceof Document) {
 
 	private final class SimpleRequestMessageCallback extends RequestMessageCallback {
 
-		SimpleRequestMessageCallback(WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
+		SimpleRequestMessageCallback(@Nullable WebServiceMessageCallback requestCallback, Message<?> requestMessage) {
 			super(requestCallback, requestMessage);
 		}
 
 		@Override
 		public void doWithMessageInternal(WebServiceMessage message, Object payload)
 				throws IOException, TransformerException {
 			Source source = this.extractSource(payload);
+			if (source == null) {
+				source = new DOMSource();
+			}
 			transform(source, message.getPayloadResult());
 			if (message instanceof MimeMessage && payload instanceof MimeMessage) {
 				copyAttachments((MimeMessage) payload, (MimeMessage) message);
 			}
 		}
 
-		private Source extractSource(Object requestPayload) throws IOException, TransformerException {
+		private @Nullable Source extractSource(Object requestPayload) throws IOException, TransformerException {
 			Source source = null;
 
 			if (requestPayload instanceof Source) {
@@ -181,14 +185,14 @@ private void copyAttachments(MimeMessage source, MimeMessage target) {
 
 	private final class SimpleResponseMessageExtractor extends ResponseMessageExtractor {
 
-		private final Result result;
+		private final @Nullable Result result;
 
-		SimpleResponseMessageExtractor(Result result) {
+		SimpleResponseMessageExtractor(@Nullable Result result) {
 			this.result = result;
 		}
 
 		@Override
-		public Object doExtractData(WebServiceMessage message) throws TransformerException {
+		public @Nullable Object doExtractData(WebServiceMessage message) throws TransformerException {
 			if (!SimpleWebServiceOutboundGateway.this.extractPayload) {
 				return message;
 			}
@@ -220,10 +224,13 @@ private static class DefaultSourceExtractor extends TransformerObjectSupport imp
 		}
 
 		@Override
-		public DOMSource extractData(Source source) throws TransformerException {
+		public @Nullable DOMSource extractData(@Nullable Source source) throws TransformerException {
 			if (source instanceof DOMSource) {
 				return (DOMSource) source;
 			}
+			else if (source == null) {
+				return new DOMSource();
+			}
 			DOMResult result = new DOMResult();
 			this.transform(source, result);
 			return new DOMSource(result.getNode());

spring-integration-ws/src/main/java/org/springframework/integration/ws/config/package-info.java

@@ -1,4 +1,5 @@
 /**
  * Contains parser classes for the Web Services namespace support.
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.ws.config;

spring-integration-ws/src/main/java/org/springframework/integration/ws/dsl/BaseWsOutboundGatewaySpec.java

@@ -53,11 +53,13 @@ public abstract class BaseWsOutboundGatewaySpec<
 
 	private final Map<String, Expression> uriVariableExpressions = new HashMap<>();
 
-	protected @Nullable WebServiceTemplate template; // NOSONAR
+	@SuppressWarnings("NullAway.Init")
+	protected WebServiceTemplate template; // NOSONAR
 
 	protected @Nullable DestinationProvider destinationProvider; // NOSONAR
 
-	protected @Nullable String uri; // NOSONAR
+	@SuppressWarnings("NullAway.Init")
+	protected String uri; // NOSONAR
 
 	protected @Nullable WebServiceMessageFactory webServiceMessageFactory; // NOSONAR
 

spring-integration-ws/src/main/java/org/springframework/integration/ws/dsl/MarshallingWsOutboundGatewaySpec.java

@@ -66,7 +66,7 @@ public static class MarshallingWsOutboundGatewayNoTemplateSpec
 			extends BaseWsOutboundGatewaySpec<MarshallingWsOutboundGatewayNoTemplateSpec,
 			MarshallingWebServiceOutboundGateway> {
 
-		protected Marshaller gatewayMarshaller = new Jaxb2Marshaller(); // NOSONAR
+		protected Marshaller gatewayMarshaller = new Jaxb2Marshaller();
 
 		protected @Nullable Unmarshaller gatewayUnmarshaller; // NOSONAR
 

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

@@ -2,4 +2,5 @@
  * Provides several inbound and outbound Web Service components. Also contains
  * support classes (e.g. Header Mapper)
  */
+@org.jspecify.annotations.NullMarked
 package org.springframework.integration.ws;