ErrorResponse support in Spring MVC exception hierarchy

All Spring MVC exceptions from spring-web, now implement ErrorResponse
and expose HTTP error response information, including an RFC 7807 body.

See gh-27052

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -22,6 +22,7 @@
 import jakarta.servlet.ServletException;
 
 import org.springframework.http.MediaType;
+import org.springframework.http.ProblemDetail;
 
 /**
  * Abstract base for exceptions related to media types. Adds a list of supported {@link MediaType MediaTypes}.
@@ -30,10 +31,12 @@
  * @since 3.0
  */
 @SuppressWarnings("serial")
-public abstract class HttpMediaTypeException extends ServletException {
+public abstract class HttpMediaTypeException extends ServletException implements ErrorResponse {
 
 	private final List<MediaType> supportedMediaTypes;
 
+	private final ProblemDetail body = ProblemDetail.forRawStatusCode(getRawStatusCode());
+
 
 	/**
 	 * Create a new HttpMediaTypeException.
@@ -61,4 +64,9 @@ public List<MediaType> getSupportedMediaTypes() {
 		return this.supportedMediaTypes;
 	}
 
+	@Override
+	public ProblemDetail getBody() {
+		return this.body;
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -18,10 +18,14 @@
 
 import java.util.List;
 
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
+import org.springframework.util.CollectionUtils;
 
 /**
- * Exception thrown when the request handler cannot generate a response that is acceptable by the client.
+ * Exception thrown when the request handler cannot generate a response that is
+ * acceptable by the client.
  *
  * @author Arjen Poutsma
  * @since 3.0
@@ -30,19 +34,36 @@
 public class HttpMediaTypeNotAcceptableException extends HttpMediaTypeException {
 
 	/**
-	 * Create a new HttpMediaTypeNotAcceptableException.
-	 * @param message the exception message
+	 * Constructor for when the {@code Accept} header cannot be parsed.
+	 * @param message the parse error message
 	 */
 	public HttpMediaTypeNotAcceptableException(String message) {
 		super(message);
+		getBody().setDetail("Could not parse Accept header");
 	}
 
 	/**
 	 * Create a new HttpMediaTypeNotSupportedException.
 	 * @param supportedMediaTypes the list of supported media types
 	 */
 	public HttpMediaTypeNotAcceptableException(List<MediaType> supportedMediaTypes) {
-		super("Could not find acceptable representation", supportedMediaTypes);
+		super("No acceptable representation", supportedMediaTypes);
+	}
+
+
+	@Override
+	public int getRawStatusCode() {
+		return HttpStatus.NOT_ACCEPTABLE.value();
+	}
+
+	@Override
+	public HttpHeaders getHeaders() {
+		if (CollectionUtils.isEmpty(getSupportedMediaTypes())) {
+			return HttpHeaders.EMPTY;
+		}
+		HttpHeaders headers = new HttpHeaders();
+		headers.setAccept(this.getSupportedMediaTypes());
+		return headers;
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -18,14 +18,19 @@
 
 import java.util.List;
 
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.lang.Nullable;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Exception thrown when a client POSTs, PUTs, or PATCHes content of a type
  * not supported by request handler.
  *
  * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
  * @since 3.0
  */
 @SuppressWarnings("serial")
@@ -34,6 +39,9 @@ public class HttpMediaTypeNotSupportedException extends HttpMediaTypeException {
 	@Nullable
 	private final MediaType contentType;
 
+	@Nullable
+	private final HttpMethod httpMethod;
+
 
 	/**
 	 * Create a new HttpMediaTypeNotSupportedException.
@@ -42,6 +50,8 @@ public class HttpMediaTypeNotSupportedException extends HttpMediaTypeException {
 	public HttpMediaTypeNotSupportedException(String message) {
 		super(message);
 		this.contentType = null;
+		this.httpMethod = null;
+		getBody().setDetail("Could not parse Content-Type");
 	}
 
 	/**
@@ -50,21 +60,38 @@ public HttpMediaTypeNotSupportedException(String message) {
 	 * @param supportedMediaTypes the list of supported media types
 	 */
 	public HttpMediaTypeNotSupportedException(@Nullable MediaType contentType, List<MediaType> supportedMediaTypes) {
-		this(contentType, supportedMediaTypes, "Content type '" +
-				(contentType != null ? contentType : "") + "' not supported");
+		this(contentType, supportedMediaTypes, null);
 	}
 
 	/**
 	 * Create a new HttpMediaTypeNotSupportedException.
 	 * @param contentType the unsupported content type
 	 * @param supportedMediaTypes the list of supported media types
-	 * @param msg the detail message
+	 * @param httpMethod the HTTP method of the request
+	 * @since 6.0
 	 */
 	public HttpMediaTypeNotSupportedException(@Nullable MediaType contentType,
-			List<MediaType> supportedMediaTypes, String msg) {
+			List<MediaType> supportedMediaTypes, @Nullable HttpMethod httpMethod) {
+
+		this(contentType, supportedMediaTypes, httpMethod,
+				"Content-Type " + (contentType != null ? "'" + contentType + "' " : "") + "is not supported");
+	}
 
-		super(msg, supportedMediaTypes);
+	/**
+	 * Create a new HttpMediaTypeNotSupportedException.
+	 * @param contentType the unsupported content type
+	 * @param supportedMediaTypes the list of supported media types
+	 * @param httpMethod the HTTP method of the request
+	 * @param message the detail message
+	 * @since 6.0
+	 */
+	public HttpMediaTypeNotSupportedException(@Nullable MediaType contentType,
+			List<MediaType> supportedMediaTypes, @Nullable HttpMethod httpMethod, String message) {
+
+		super(message, supportedMediaTypes);
 		this.contentType = contentType;
+		this.httpMethod = httpMethod;
+		getBody().setDetail("Content-Type " + this.contentType + " is not supported");
 	}
 
 
@@ -76,4 +103,22 @@ public MediaType getContentType() {
 		return this.contentType;
 	}
 
+	@Override
+	public int getRawStatusCode() {
+		return HttpStatus.UNSUPPORTED_MEDIA_TYPE.value();
+	}
+
+	@Override
+	public HttpHeaders getHeaders() {
+		if (CollectionUtils.isEmpty(getSupportedMediaTypes())) {
+			return HttpHeaders.EMPTY;
+		}
+		HttpHeaders headers = new HttpHeaders();
+		headers.setAccept(getSupportedMediaTypes());
+		if (HttpMethod.PATCH.equals(this.httpMethod)) {
+			headers.setAcceptPatch(getSupportedMediaTypes());
+		}
+		return headers;
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -22,8 +22,12 @@
 
 import jakarta.servlet.ServletException;
 
+import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ProblemDetail;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -34,13 +38,15 @@
  * @since 2.0
  */
 @SuppressWarnings("serial")
-public class HttpRequestMethodNotSupportedException extends ServletException {
+public class HttpRequestMethodNotSupportedException extends ServletException implements ErrorResponse {
 
 	private final String method;
 
 	@Nullable
 	private final String[] supportedMethods;
 
+	private final ProblemDetail body;
+
 
 	/**
 	 * Create a new HttpRequestMethodNotSupportedException.
@@ -74,7 +80,7 @@ public HttpRequestMethodNotSupportedException(String method, @Nullable Collectio
 	 * @param supportedMethods the actually supported HTTP methods (may be {@code null})
 	 */
 	public HttpRequestMethodNotSupportedException(String method, @Nullable String[] supportedMethods) {
-		this(method, supportedMethods, "Request method '" + method + "' not supported");
+		this(method, supportedMethods, "Request method '" + method + "' is not supported");
 	}
 
 	/**
@@ -87,6 +93,8 @@ public HttpRequestMethodNotSupportedException(String method, @Nullable String[]
 		super(msg);
 		this.method = method;
 		this.supportedMethods = supportedMethods;
+		this.body = ProblemDetail.forRawStatusCode(getRawStatusCode())
+				.withDetail("Method '" + method + "' is not supported");
 	}
 
 
@@ -123,4 +131,24 @@ public Set<HttpMethod> getSupportedHttpMethods() {
 		return supportedMethods;
 	}
 
+	@Override
+	public int getRawStatusCode() {
+		return HttpStatus.METHOD_NOT_ALLOWED.value();
+	}
+
+	@Override
+	public HttpHeaders getHeaders() {
+		if (ObjectUtils.isEmpty(this.supportedMethods)) {
+			return HttpHeaders.EMPTY;
+		}
+		HttpHeaders headers = new HttpHeaders();
+		headers.add(HttpHeaders.ALLOW, StringUtils.arrayToDelimitedString(this.supportedMethods, ", "));
+		return headers;
+	}
+
+	@Override
+	public ProblemDetail getBody() {
+		return this.body;
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -17,9 +17,12 @@
 package org.springframework.web.bind;
 
 import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ProblemDetail;
 import org.springframework.validation.BindException;
 import org.springframework.validation.BindingResult;
 import org.springframework.validation.ObjectError;
+import org.springframework.web.ErrorResponse;
 
 /**
  * Exception to be thrown when validation on an argument annotated with {@code @Valid} fails.
@@ -30,10 +33,12 @@
  * @since 3.1
  */
 @SuppressWarnings("serial")
-public class MethodArgumentNotValidException extends BindException {
+public class MethodArgumentNotValidException extends BindException implements ErrorResponse {
 
 	private final MethodParameter parameter;
 
+	private final ProblemDetail body;
+
 
 	/**
 	 * Constructor for {@link MethodArgumentNotValidException}.
@@ -43,9 +48,20 @@ public class MethodArgumentNotValidException extends BindException {
 	public MethodArgumentNotValidException(MethodParameter parameter, BindingResult bindingResult) {
 		super(bindingResult);
 		this.parameter = parameter;
+		this.body = ProblemDetail.forRawStatusCode(getRawStatusCode()).withDetail(initMessage(parameter));
 	}
 
 
+	@Override
+	public int getRawStatusCode() {
+		return HttpStatus.BAD_REQUEST.value();
+	}
+
+	@Override
+	public ProblemDetail getBody() {
+		return this.body;
+	}
+
 	/**
 	 * Return the method parameter that failed validation.
 	 */
@@ -55,9 +71,13 @@ public final MethodParameter getParameter() {
 
 	@Override
 	public String getMessage() {
+		return initMessage(this.parameter);
+	}
+
+	private String initMessage(MethodParameter parameter) {
 		StringBuilder sb = new StringBuilder("Validation failed for argument [")
-				.append(this.parameter.getParameterIndex()).append("] in ")
-				.append(this.parameter.getExecutable().toGenericString());
+				.append(parameter.getParameterIndex()).append("] in ")
+				.append(parameter.getExecutable().toGenericString());
 		BindingResult bindingResult = getBindingResult();
 		if (bindingResult.getErrorCount() > 1) {
 			sb.append(" with ").append(bindingResult.getErrorCount()).append(" errors");

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 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.
@@ -57,6 +57,7 @@ public MissingMatrixVariableException(
 		super("", missingAfterConversion);
 		this.variableName = variableName;
 		this.parameter = parameter;
+		getBody().setDetail("Required path parameter '" + this.variableName + "' is not present");
 	}