Remove HttpStatus from HttpMessageConversionException

HttpMessageConverter's are client and server and arguably shouldn't
contain a server-side concept such a response status.

The status field is recent, it was added to differentiate 400 vs 500
errors with Jackson 2.9+ but there is no need for it since the same
distinction is reflected in raising an HttpMessageNotReadableException
vs a general HttpMessageConversionException.

Issue: SPR-15516

spring-web/src/main/java/org/springframework/http/converter/HttpMessageConversionException.java

@@ -17,9 +17,6 @@
 package org.springframework.http.converter;
 
 import org.springframework.core.NestedRuntimeException;
-import org.springframework.http.HttpStatus;
-
-import java.util.Optional;
 
 /**
  * Thrown by {@link HttpMessageConverter} implementations when a conversion attempt fails.
@@ -31,15 +28,12 @@ import java.util.Optional;
 @SuppressWarnings("serial")
 public class HttpMessageConversionException extends NestedRuntimeException {
 
-	private final HttpStatus errorStatus;
-
 	/**
 	 * Create a new HttpMessageConversionException.
 	 * @param msg the detail message
 	 */
 	public HttpMessageConversionException(String msg) {
 		super(msg);
-		this.errorStatus = null;
 	}
 
 	/**
@@ -49,25 +43,6 @@ public class HttpMessageConversionException extends NestedRuntimeException {
 	 */
 	public HttpMessageConversionException(String msg, Throwable cause) {
 		super(msg, cause);
-		this.errorStatus = null;
 	}
 
-	/**
-	 * Create a new HttpMessageConversionException.
-	 * @since 5.0
-	 * @param msg the detail message
-	 * @param cause the root cause (if any)
-	 * @param errorStatus the HTTP error status related to this exception
-	 */
-	public HttpMessageConversionException(String msg, Throwable cause, HttpStatus errorStatus) {
-		super(msg, cause);
-		this.errorStatus = errorStatus;
-	}
-
-	/**
-	 * Return the HTTP error status related to this exception if any.
-	 */
-	public Optional<HttpStatus> getErrorStatus() {
-		return Optional.ofNullable(errorStatus);
-	}
 }

spring-web/src/main/java/org/springframework/http/converter/HttpMessageNotReadableException.java

@@ -16,8 +16,6 @@
 
 package org.springframework.http.converter;
 
-import org.springframework.http.HttpStatus;
-
 /**
  * Thrown by {@link HttpMessageConverter} implementations when the
  * {@link HttpMessageConverter#read} method fails.
@@ -45,15 +43,4 @@ public class HttpMessageNotReadableException extends HttpMessageConversionExcept
 		super(msg, cause);
 	}
 
-	/**
-	 * Create a new HttpMessageNotReadableException.
-	 * @since 5.0
-	 * @param msg the detail message
-	 * @param cause the root cause (if any)
-	 * @param errorStatus the HTTP error status related to this exception
-	 */
-	public HttpMessageNotReadableException(String msg, Throwable cause, HttpStatus errorStatus) {
-		super(msg, cause, errorStatus);
-	}
-
 }

spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java

@@ -41,9 +41,9 @@ import com.fasterxml.jackson.databind.type.TypeFactory;
 import org.springframework.core.GenericTypeResolver;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
-import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.AbstractGenericHttpMessageConverter;
+import org.springframework.http.converter.HttpMessageConversionException;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
@@ -230,11 +230,13 @@ public abstract class AbstractJackson2HttpMessageConverter extends AbstractGener
 			return this.objectMapper.readValue(inputMessage.getBody(), javaType);
 		}
 		catch (InvalidDefinitionException ex) {
-			throw new HttpMessageNotReadableException(
-					"Could not map JSON to target object of " + javaType, ex, HttpStatus.INTERNAL_SERVER_ERROR);
+			throw new HttpMessageConversionException("Type definition error: " + ex.getMessage(), ex);
+		}
+		catch (JsonProcessingException ex) {
+			throw new HttpMessageNotReadableException("JSON parse error: " + ex.getMessage(), ex);
 		}
 		catch (IOException ex) {
-			throw new HttpMessageNotReadableException("Could not read JSON document: " + ex.getMessage(), ex);
+			throw new HttpMessageNotReadableException("I/O error while reading: " + ex.getMessage(), ex);
 		}
 	}
 

spring-web/src/test/java/org/springframework/http/converter/json/MappingJackson2HttpMessageConverterTests.java

@@ -34,14 +34,21 @@ import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;
 import org.junit.Test;
 
 import org.springframework.core.ParameterizedTypeReference;
-import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.MockHttpInputMessage;
 import org.springframework.http.MockHttpOutputMessage;
+import org.springframework.http.converter.HttpMessageConversionException;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 
-import static org.hamcrest.CoreMatchers.*;
-import static org.junit.Assert.*;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.endsWith;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.startsWith;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 /**
  * Jackson 2.x converter tests.
@@ -388,9 +395,8 @@ public class MappingJackson2HttpMessageConverterTests {
 		try {
 			converter.read(BeanWithNoDefaultConstructor.class, inputMessage);
 		}
-		catch (HttpMessageNotReadableException ex) {
-			assertTrue(ex.getErrorStatus().isPresent());
-			assertEquals(HttpStatus.INTERNAL_SERVER_ERROR, ex.getErrorStatus().get());
+		catch (HttpMessageConversionException ex) {
+			assertTrue(ex.getMessage(), ex.getMessage().startsWith("Type definition error:"));
 			return;
 		}
 		fail();

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/support/DefaultHandlerExceptionResolver.java

@@ -27,7 +27,6 @@ import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.ConversionNotSupportedException;
 import org.springframework.beans.TypeMismatchException;
 import org.springframework.core.Ordered;
-import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
@@ -355,7 +354,7 @@ public class DefaultHandlerExceptionResolver extends AbstractHandlerExceptionRes
 		if (logger.isWarnEnabled()) {
 			logger.warn("Failed to read HTTP message: " + ex);
 		}
-		response.sendError(ex.getErrorStatus().orElse(HttpStatus.BAD_REQUEST).value());
+		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 		return new ModelAndView();
 	}
 

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ServletAnnotationControllerHandlerMethodTests.java

@@ -141,7 +141,14 @@ import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 import org.springframework.web.servlet.support.RequestContextUtils;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 /**
  * @author Rossen Stoyanchev