Replace deep exception message nesting with custom inclusion of cause messages

Includes deprecation of NestedServletException, whereas NestedCheckedException and NestedRuntimeException remain as base classes with several convenience methods.

Closes gh-25162

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

@@ -75,7 +75,7 @@ public abstract class AbstractXmlHttpMessageConverter<T> extends AbstractHttpMes
 			throw ex;
 		}
 		catch (Exception ex) {
-			throw new HttpMessageNotReadableException("Could not unmarshal to [" + clazz + "]: " + ex.getMessage(),
+			throw new HttpMessageNotReadableException("Could not unmarshal to [" + clazz + "]: " + ex,
 					ex, inputMessage);
 		}
 	}

spring-web/src/main/java/org/springframework/http/converter/xml/Jaxb2CollectionHttpMessageConverter.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.
@@ -173,7 +173,7 @@ public class Jaxb2CollectionHttpMessageConverter<T extends Collection>
 		}
 		catch (UnmarshalException ex) {
 			throw new HttpMessageNotReadableException(
-					"Could not unmarshal to [" + elementClass + "]: " + ex.getMessage(), ex, inputMessage);
+					"Could not unmarshal to [" + elementClass + "]: " + ex, ex, inputMessage);
 		}
 		catch (JAXBException ex) {
 			throw new HttpMessageConversionException("Invalid JAXB setup: " + ex.getMessage(), ex);

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

@@ -18,14 +18,12 @@ package org.springframework.web;
 
 import java.net.URI;
 
-import org.springframework.core.NestedExceptionUtils;
 import org.springframework.core.NestedRuntimeException;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatusCode;
 import org.springframework.http.ProblemDetail;
 import org.springframework.lang.Nullable;
 
-
 /**
  * {@link RuntimeException} that implements {@link ErrorResponse} to expose
  * an HTTP status, response headers, and a body formatted as an RFC 7808
@@ -137,8 +135,7 @@ public class ErrorResponseException extends NestedRuntimeException implements Er
 
 	@Override
 	public String getMessage() {
-		String message = this.status + (!this.headers.isEmpty() ? ", headers=" + this.headers : "") + ", " + this.body;
-		return NestedExceptionUtils.buildMessage(message, getCause());
+		return this.status + (!this.headers.isEmpty() ? ", headers=" + this.headers : "") + ", " + this.body;
 	}
 
 }

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

@@ -16,11 +16,12 @@
 
 package org.springframework.web.bind;
 
+import jakarta.servlet.ServletException;
+
 import org.springframework.http.HttpStatus;
 import org.springframework.http.HttpStatusCode;
 import org.springframework.http.ProblemDetail;
 import org.springframework.web.ErrorResponse;
-import org.springframework.web.util.NestedServletException;
 
 /**
  * Fatal binding exception, thrown when we want to
@@ -34,7 +35,7 @@ import org.springframework.web.util.NestedServletException;
  * @author Juergen Hoeller
  */
 @SuppressWarnings("serial")
-public class ServletRequestBindingException extends NestedServletException implements ErrorResponse {
+public class ServletRequestBindingException extends ServletException implements ErrorResponse {
 
 	private final ProblemDetail body = ProblemDetail.forStatus(getStatusCode());
 

spring-web/src/main/java/org/springframework/web/filter/GenericFilterBean.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -49,7 +49,6 @@ import org.springframework.util.StringUtils;
 import org.springframework.web.context.ServletContextAware;
 import org.springframework.web.context.support.ServletContextResourceLoader;
 import org.springframework.web.context.support.StandardServletEnvironment;
-import org.springframework.web.util.NestedServletException;
 
 /**
  * Simple base implementation of {@link jakarta.servlet.Filter} which treats
@@ -228,9 +227,9 @@ public abstract class GenericFilterBean implements Filter, BeanNameAware, Enviro
 			}
 			catch (BeansException ex) {
 				String msg = "Failed to set bean properties on filter '" +
-					filterConfig.getFilterName() + "': " + ex.getMessage();
+						filterConfig.getFilterName() + "': " + ex.getMessage();
 				logger.error(msg, ex);
-				throw new NestedServletException(msg, ex);
+				throw new ServletException(msg, ex);
 			}
 		}
 

spring-web/src/main/java/org/springframework/web/server/ResponseStatusException.java

@@ -16,7 +16,6 @@
 
 package org.springframework.web.server;
 
-import org.springframework.core.NestedExceptionUtils;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatusCode;
 import org.springframework.lang.Nullable;
@@ -112,8 +111,7 @@ public class ResponseStatusException extends ErrorResponseException {
 
 	@Override
 	public String getMessage() {
-		String msg = getStatusCode() + (this.reason != null ? " \"" + this.reason + "\"" : "");
-		return NestedExceptionUtils.buildMessage(msg, getCause());
+		return getStatusCode() + (this.reason != null ? " \"" + this.reason + "\"" : "");
 	}
 
 }

spring-web/src/main/java/org/springframework/web/util/NestedServletException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 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.
@@ -37,10 +37,11 @@ import org.springframework.lang.Nullable;
  * @author Juergen Hoeller
  * @since 1.2.5
  * @see #getMessage
- * @see #printStackTrace
  * @see org.springframework.core.NestedCheckedException
  * @see org.springframework.core.NestedRuntimeException
+ * @deprecated as of 6.0, in favor of standard {@link ServletException} nesting
  */
+@Deprecated
 public class NestedServletException extends ServletException {
 
 	/** Use serialVersionUID from Spring 1.2 for interoperability. */
@@ -68,18 +69,7 @@ public class NestedServletException extends ServletException {
 	 * @param cause the nested exception
 	 */
 	public NestedServletException(@Nullable String msg, @Nullable Throwable cause) {
-		super(msg, cause);
-	}
-
-
-	/**
-	 * Return the detail message, including the message from the nested exception
-	 * if there is one.
-	 */
-	@Override
-	@Nullable
-	public String getMessage() {
-		return NestedExceptionUtils.buildMessage(super.getMessage(), getCause());
+		super(NestedExceptionUtils.buildMessage(msg, cause), cause);
 	}
 
 }