Refine null-safety in spring-web and spring-websocket

See gh-32475

Author: sdeleuze

spring-web/src/main/java/org/springframework/web/DefaultErrorResponseBuilder.java

@@ -211,6 +211,7 @@ public String getDetailMessageCode() {
 		}
 
 		@Override
+		@Nullable
 		public Object[] getDetailMessageArguments() {
 			return this.detailMessageArguments;
 		}

spring-web/src/main/java/org/springframework/web/ErrorResponseException.java

@@ -165,6 +165,7 @@ public String getDetailMessageCode() {
 	}
 
 	@Override
+	@Nullable
 	public Object[] getDetailMessageArguments() {
 		return this.messageDetailArguments;
 	}

spring-web/src/main/java/org/springframework/web/HttpMediaTypeException.java

@@ -73,7 +73,7 @@ protected HttpMediaTypeException(String message, List<MediaType> supportedMediaT
 	 * resolving the problem "detail" through a {@code MessageSource}
 	 * @since 6.0
 	 */
-	protected HttpMediaTypeException(String message, List<MediaType> supportedMediaTypes,
+	protected HttpMediaTypeException(@Nullable String message, List<MediaType> supportedMediaTypes,
 			@Nullable String messageDetailCode, @Nullable Object[] messageDetailArguments) {
 
 		super(message);
@@ -102,6 +102,7 @@ public String getDetailMessageCode() {
 	}
 
 	@Override
+	@Nullable
 	public Object[] getDetailMessageArguments() {
 		return this.messageDetailArguments;
 	}

spring-web/src/main/java/org/springframework/web/HttpMediaTypeNotSupportedException.java

@@ -63,7 +63,7 @@ public HttpMediaTypeNotSupportedException(String message) {
 	 * @param mediaTypes list of supported media types
 	 * @since 6.0.5
 	 */
-	public HttpMediaTypeNotSupportedException(String message, List<MediaType> mediaTypes) {
+	public HttpMediaTypeNotSupportedException(@Nullable String message, List<MediaType> mediaTypes) {
 		super(message, mediaTypes, PARSE_ERROR_DETAIL_CODE, null);
 		this.contentType = null;
 		this.httpMethod = null;

spring-web/src/main/java/org/springframework/web/accept/ServletPathExtensionContentNegotiationStrategy.java

@@ -99,6 +99,7 @@ protected MediaType handleNoMatch(NativeWebRequest webRequest, String extension)
 	 * @since 4.3
 	 */
 	@Override
+	@Nullable
 	public MediaType getMediaTypeForResource(Resource resource) {
 		MediaType mediaType = null;
 		String mimeType = this.servletContext.getMimeType(resource.getFilename());

spring-web/src/main/java/org/springframework/web/bind/ServletRequestBindingException.java

@@ -50,7 +50,7 @@ public class ServletRequestBindingException extends ServletException implements
 	 * Constructor with a message only.
 	 * @param msg the detail message
 	 */
-	public ServletRequestBindingException(String msg) {
+	public ServletRequestBindingException(@Nullable String msg) {
 		this(msg, null, null);
 	}
 
@@ -59,7 +59,7 @@ public ServletRequestBindingException(String msg) {
 	 * @param msg the detail message
 	 * @param cause the root cause
 	 */
-	public ServletRequestBindingException(String msg, Throwable cause) {
+	public ServletRequestBindingException(@Nullable String msg, @Nullable Throwable cause) {
 		this(msg, cause, null, null);
 	}
 
@@ -73,7 +73,7 @@ public ServletRequestBindingException(String msg, Throwable cause) {
 	 * @since 6.0
 	 */
 	protected ServletRequestBindingException(
-			String msg, @Nullable String messageDetailCode, @Nullable Object[] messageDetailArguments) {
+			@Nullable String msg, @Nullable String messageDetailCode, @Nullable Object[] messageDetailArguments) {
 
 		this(msg, null, messageDetailCode, messageDetailArguments);
 	}
@@ -88,7 +88,7 @@ protected ServletRequestBindingException(
 	 * resolving the problem "detail" through a {@code MessageSource}
 	 * @since 6.0
 	 */
-	protected ServletRequestBindingException(String msg, @Nullable Throwable cause,
+	protected ServletRequestBindingException(@Nullable String msg, @Nullable Throwable cause,
 			@Nullable String messageDetailCode, @Nullable Object[] messageDetailArguments) {
 
 		super(msg, cause);
@@ -118,6 +118,7 @@ public String getDetailMessageCode() {
 	}
 
 	@Override
+	@Nullable
 	public Object[] getDetailMessageArguments() {
 		return this.messageDetailArguments;
 	}

spring-web/src/main/java/org/springframework/web/bind/support/BindParamNameResolver.java

@@ -17,6 +17,7 @@
 package org.springframework.web.bind.support;
 
 import org.springframework.core.MethodParameter;
+import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 import org.springframework.validation.DataBinder;
 import org.springframework.web.bind.annotation.BindParam;
@@ -32,6 +33,7 @@
 public final class BindParamNameResolver implements DataBinder.NameResolver {
 
 	@Override
+	@Nullable
 	public String resolveName(MethodParameter parameter) {
 		BindParam bindParam = parameter.getParameterAnnotation(BindParam.class);
 		if (bindParam != null) {

spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeDataBinder.java

@@ -162,6 +162,7 @@ protected static void addBindValue(Map<String, Object> params, String key, List<
 	private record MapValueResolver(Map<String, Object> map) implements ValueResolver {
 
 		@Override
+		@Nullable
 		public Object resolveValue(String name, Class<?> type) {
 			return this.map.get(name);
 		}

spring-web/src/main/java/org/springframework/web/client/HttpMessageConverterExtractor.java

@@ -84,6 +84,7 @@ public HttpMessageConverterExtractor(Type responseType, List<HttpMessageConverte
 
 
 	@Override
+	@Nullable
 	@SuppressWarnings({"rawtypes", "unchecked", "resource"})
 	public T extractData(ClientHttpResponse response) throws IOException {
 		IntrospectingClientHttpResponse responseWrapper = new IntrospectingClientHttpResponse(response);

spring-web/src/main/java/org/springframework/web/client/ResourceAccessException.java

@@ -18,6 +18,8 @@
 
 import java.io.IOException;
 
+import org.springframework.lang.Nullable;
+
 /**
  * Exception thrown when an I/O error occurs.
  *
@@ -42,7 +44,7 @@ public ResourceAccessException(String msg) {
 	 * @param msg the message
 	 * @param ex the {@code IOException}
 	 */
-	public ResourceAccessException(String msg, IOException ex) {
+	public ResourceAccessException(String msg, @Nullable IOException ex) {
 		super(msg, ex);
 	}