Simplify error page config by dropping redundant support for Tomcat 7

Closes gh-17937

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatErrorPage.java

-/*
- * Copyright 2012-2019 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.
- * You may obtain a copy of the License at
- *
- *      https://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.springframework.boot.web.embedded.tomcat;
-
-import java.lang.reflect.Method;
-
-import org.apache.catalina.Context;
-
-import org.springframework.beans.BeanUtils;
-import org.springframework.boot.web.server.ErrorPage;
-import org.springframework.util.Assert;
-import org.springframework.util.ClassUtils;
-import org.springframework.util.ReflectionUtils;
-
-/**
- * Tomcat specific management for an {@link ErrorPage}.
- *
- * @author Dave Syer
- * @author Phillip Webb
- */
-class TomcatErrorPage {
-
-	private static final String ERROR_PAGE_CLASS = "org.apache.tomcat.util.descriptor.web.ErrorPage";
-
-	private final String location;
-
-	private final String exceptionType;
-
-	private final int errorCode;
-
-	private final Object nativePage;
-
-	TomcatErrorPage(ErrorPage errorPage) {
-		this.location = errorPage.getPath();
-		this.exceptionType = errorPage.getExceptionName();
-		this.errorCode = errorPage.getStatusCode();
-		this.nativePage = createNativePage();
-	}
-
-	private Object createNativePage() {
-		try {
-			if (ClassUtils.isPresent(ERROR_PAGE_CLASS, null)) {
-				return BeanUtils.instantiateClass(ClassUtils.forName(ERROR_PAGE_CLASS, null));
-			}
-		}
-		catch (ClassNotFoundException | LinkageError ex) {
-			// Swallow and continue
-		}
-		return null;
-	}
-
-	void addToContext(Context context) {
-		Assert.state(this.nativePage != null, "No Tomcat 8 detected so no native error page exists");
-		if (ClassUtils.isPresent(ERROR_PAGE_CLASS, null)) {
-			org.apache.tomcat.util.descriptor.web.ErrorPage errorPage = (org.apache.tomcat.util.descriptor.web.ErrorPage) this.nativePage;
-			errorPage.setLocation(this.location);
-			errorPage.setErrorCode(this.errorCode);
-			errorPage.setExceptionType(this.exceptionType);
-			context.addErrorPage(errorPage);
-		}
-		else {
-			callMethod(this.nativePage, "setLocation", this.location, String.class);
-			callMethod(this.nativePage, "setErrorCode", this.errorCode, int.class);
-			callMethod(this.nativePage, "setExceptionType", this.exceptionType, String.class);
-			callMethod(context, "addErrorPage", this.nativePage, this.nativePage.getClass());
-		}
-	}
-
-	private void callMethod(Object target, String name, Object value, Class<?> type) {
-		Method method = ReflectionUtils.findMethod(target.getClass(), name, type);
-		ReflectionUtils.invokeMethod(method, target, value);
-	}
-
-}

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactory.java

@@ -362,7 +362,11 @@ public class TomcatServletWebServerFactory extends AbstractServletWebServerFacto
 			context.getPipeline().addValve(valve);
 		}
 		for (ErrorPage errorPage : getErrorPages()) {
-			new TomcatErrorPage(errorPage).addToContext(context);
+			org.apache.tomcat.util.descriptor.web.ErrorPage tomcatErrorPage = new org.apache.tomcat.util.descriptor.web.ErrorPage();
+			tomcatErrorPage.setLocation(errorPage.getPath());
+			tomcatErrorPage.setErrorCode(errorPage.getStatusCode());
+			tomcatErrorPage.setExceptionType(errorPage.getExceptionName());
+			context.addErrorPage(tomcatErrorPage);
 		}
 		for (MimeMappings.Mapping mapping : getMimeMappings()) {
 			context.addMimeMapping(mapping.getExtension(), mapping.getMimeType());