BadRequestStatusException -> ServerWebInputException

The renaming makes it clear this exception is for use where 400 error
applies within a Spring web application where the error may be
associated with a MethodParameter, a BindingResult, and so on.

There is no need for BadRequestStatusException which can be expressed
with ResponseStatusException(HttpStatus.BAD_REQUEST, "reason").

spring-web-reactive/src/main/java/org/springframework/web/reactive/result/method/RequestMappingInfoHandlerMapping.java

@@ -43,7 +43,7 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.reactive.HandlerMapping;
 import org.springframework.web.reactive.result.condition.ParamsRequestCondition;
-import org.springframework.web.server.BadRequestStatusException;
+import org.springframework.web.server.ServerWebInputException;
 import org.springframework.web.server.MethodNotAllowedException;
 import org.springframework.web.server.NotAcceptableStatusException;
 import org.springframework.web.server.ServerWebExchange;
@@ -203,7 +203,7 @@ public abstract class RequestMappingInfoHandlerMapping extends AbstractHandlerMe
 	 * and HTTP method but not by consumable media types
 	 * @throws NotAcceptableStatusException if there are matches by URL and HTTP
 	 * method but not by producible media types
-	 * @throws BadRequestStatusException if there are matches by URL and HTTP
+	 * @throws ServerWebInputException if there are matches by URL and HTTP
 	 * method but not by query parameter conditions
 	 */
 	@Override
@@ -278,7 +278,7 @@ public abstract class RequestMappingInfoHandlerMapping extends AbstractHandlerMe
 						.collect(Collectors.toMap(Entry::getKey,
 								entry -> entry.getValue().toArray(new String[entry.getValue().size()]))
 				);
-				throw new BadRequestStatusException("Unsatisfied query parameter conditions: " +
+				throw new ServerWebInputException("Unsatisfied query parameter conditions: " +
 						paramConditions + ", actual parameters: " + params);
 			}
 			else {

spring-web-reactive/src/main/java/org/springframework/web/server/BadRequestStatusException.java → spring-web-reactive/src/main/java/org/springframework/web/server/ServerWebInputException.java

@@ -21,11 +21,13 @@ import org.springframework.core.MethodParameter;
 import org.springframework.http.HttpStatus;
 
 /**
- * Exception for errors that fit response status 400 (bad request).
+ * Exception for errors that fit response status 400 (bad request) for use in
+ * Spring Web applications. The exception provides additional fields (e.g.
+ * an optional {@link MethodParameter} if related to the error).
  *
  * @author Rossen Stoyanchev
  */
-public class BadRequestStatusException extends ResponseStatusException {
+public class ServerWebInputException extends ResponseStatusException {
 
 	private final MethodParameter parameter;
 
@@ -33,21 +35,21 @@ public class BadRequestStatusException extends ResponseStatusException {
 	/**
 	 * Constructor with an explanation only.
 	 */
-	public BadRequestStatusException(String reason) {
+	public ServerWebInputException(String reason) {
 		this(reason, null);
 	}
 
 	/**
 	 * Constructor for a 400 error linked to a specific {@code MethodParameter}.
 	 */
-	public BadRequestStatusException(String reason, MethodParameter parameter) {
+	public ServerWebInputException(String reason, MethodParameter parameter) {
 		this(reason, parameter, null);
 	}
 
 	/**
 	 * Constructor for a 400 error with a root cause.
 	 */
-	public BadRequestStatusException(String reason, MethodParameter parameter, Throwable cause) {
+	public ServerWebInputException(String reason, MethodParameter parameter, Throwable cause) {
 		super(HttpStatus.BAD_REQUEST, reason, cause);
 		this.parameter = parameter;
 	}

spring-web-reactive/src/test/java/org/springframework/web/reactive/result/method/RequestMappingInfoHandlerMappingTests.java

@@ -50,7 +50,7 @@ import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.reactive.HandlerMapping;
 import org.springframework.web.reactive.HandlerResult;
 import org.springframework.web.reactive.result.method.RequestMappingInfo.BuilderConfiguration;
-import org.springframework.web.server.BadRequestStatusException;
+import org.springframework.web.server.ServerWebInputException;
 import org.springframework.web.server.MethodNotAllowedException;
 import org.springframework.web.server.NotAcceptableStatusException;
 import org.springframework.web.server.ServerWebExchange;
@@ -208,7 +208,7 @@ public class RequestMappingInfoHandlerMappingTests {
 	public void getHandlerUnsatisfiedServletRequestParameterException() throws Exception {
 		ServerWebExchange exchange = createExchange(HttpMethod.GET, "/params");
 		Mono<Object> mono = this.handlerMapping.getHandler(exchange);
-		assertError(mono, BadRequestStatusException.class, ex -> {
+		assertError(mono, ServerWebInputException.class, ex -> {
 			assertEquals(ex.getReason(), "Unsatisfied query parameter conditions: " +
 					"[[bar=baz], [foo=bar]], actual parameters: {}");
 		});