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-webmvc/src/main/java/org/springframework/web/servlet/DispatcherServlet.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.
@@ -62,7 +62,6 @@ import org.springframework.web.context.request.async.WebAsyncUtils;
 import org.springframework.web.multipart.MultipartException;
 import org.springframework.web.multipart.MultipartHttpServletRequest;
 import org.springframework.web.multipart.MultipartResolver;
-import org.springframework.web.util.NestedServletException;
 import org.springframework.web.util.ServletRequestPathUtils;
 import org.springframework.web.util.WebUtils;
 
@@ -1077,7 +1076,7 @@ public class DispatcherServlet extends FrameworkServlet {
 			catch (Throwable err) {
 				// As of 4.3, we're processing Errors thrown from handler methods as well,
 				// making them available for @ExceptionHandler methods and other scenarios.
-				dispatchException = new NestedServletException("Handler dispatch failed", err);
+				dispatchException = new ServletException("Handler dispatch failed: " + err, err);
 			}
 			processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);
 		}
@@ -1086,7 +1085,7 @@ public class DispatcherServlet extends FrameworkServlet {
 		}
 		catch (Throwable err) {
 			triggerAfterCompletion(processedRequest, response, mappedHandler,
-					new NestedServletException("Handler processing failed", err));
+					new ServletException("Handler processing failed: " + err, err));
 		}
 		finally {
 			if (asyncManager.isConcurrentHandlingStarted()) {

spring-webmvc/src/main/java/org/springframework/web/servlet/FrameworkServlet.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.
@@ -68,7 +68,6 @@ import org.springframework.web.context.support.ServletRequestHandledEvent;
 import org.springframework.web.context.support.WebApplicationContextUtils;
 import org.springframework.web.context.support.XmlWebApplicationContext;
 import org.springframework.web.cors.CorsUtils;
-import org.springframework.web.util.NestedServletException;
 import org.springframework.web.util.WebUtils;
 
 /**
@@ -1009,7 +1008,7 @@ public abstract class FrameworkServlet extends HttpServletBean implements Applic
 		}
 		catch (Throwable ex) {
 			failureCause = ex;
-			throw new NestedServletException("Request processing failed", ex);
+			throw new ServletException("Request processing failed: " + ex, ex);
 		}
 
 		finally {

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ServletInvocableHandlerMethod.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.
@@ -22,6 +22,7 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Type;
 import java.util.concurrent.Callable;
 
+import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 
@@ -44,7 +45,6 @@ import org.springframework.web.method.support.HandlerMethodReturnValueHandlerCom
 import org.springframework.web.method.support.InvocableHandlerMethod;
 import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.servlet.View;
-import org.springframework.web.util.NestedServletException;
 
 /**
  * Extends {@link InvocableHandlerMethod} with the ability to handle return
@@ -220,7 +220,7 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 					throw (Exception) result;
 				}
 				else if (result instanceof Throwable) {
-					throw new NestedServletException("Async processing failed", (Throwable) result);
+					throw new ServletException("Async processing failed: " + result, (Throwable) result);
 				}
 				return result;
 			}, CALLABLE_METHOD);

spring-webmvc/src/main/java/org/springframework/web/servlet/view/groovy/GroovyMarkupView.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.
@@ -23,6 +23,7 @@ import java.util.Map;
 
 import groovy.text.Template;
 import groovy.text.markup.MarkupTemplateEngine;
+import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 
@@ -34,7 +35,6 @@ import org.springframework.context.ApplicationContextException;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.web.servlet.view.AbstractTemplateView;
-import org.springframework.web.util.NestedServletException;
 
 /**
  * An {@link AbstractTemplateView} subclass based on Groovy XML/XHTML markup templates.
@@ -133,7 +133,7 @@ public class GroovyMarkupView extends AbstractTemplateView {
 		}
 		catch (ClassNotFoundException ex) {
 			Throwable cause = (ex.getCause() != null ? ex.getCause() : ex);
-			throw new NestedServletException(
+			throw new ServletException(
 					"Could not find class while rendering Groovy Markup view with name '" +
 					getUrl() + "': " + ex.getMessage() + "'", cause);
 		}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ExceptionHandlerExceptionResolverTests.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.
@@ -23,6 +23,7 @@ import java.net.SocketTimeoutException;
 import java.util.Collections;
 import java.util.Locale;
 
+import jakarta.servlet.ServletException;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -61,7 +62,6 @@ import org.springframework.web.servlet.mvc.support.RedirectAttributes;
 import org.springframework.web.servlet.resource.ResourceHttpRequestHandler;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
 import org.springframework.web.testfixture.servlet.MockHttpServletResponse;
-import org.springframework.web.util.NestedServletException;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -315,7 +315,7 @@ public class ExceptionHandlerExceptionResolverTests {
 		AssertionError err = new AssertionError("argh");
 		HandlerMethod handlerMethod = new HandlerMethod(new ResponseBodyController(), "handle");
 		ModelAndView mav = this.resolver.resolveException(this.request, this.response, handlerMethod,
-				new NestedServletException("Handler dispatch failed", err));
+				new ServletException("Handler dispatch failed", err));
 
 		assertThat(mav).as("Exception was not handled").isNotNull();
 		assertThat(mav.isEmpty()).isTrue();