Restructure web auto-configuration

Restructure `org.springframework.boot.autoconfigure.web` to better align
with the new package structure in `spring-boot`.

Auto-configuration is now split into client, servlet and reactive
sub-packages. In addition a new `http` package now handles common
HTTP concerns.

Fixes gh-8616

spring-boot/src/test/java/org/springframework/boot/web/reactive/server/AbstractReactiveWebServerFactoryTests.java

@@ -16,7 +16,12 @@
 
 package org.springframework.boot.web.reactive.server;
 
+import java.net.URL;
+
+import org.apache.catalina.webresources.TomcatURLStreamHandlerFactory;
 import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
@@ -31,6 +36,7 @@ import org.springframework.http.MediaType;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.SocketUtils;
 import org.springframework.web.reactive.function.BodyInserters;
 import org.springframework.web.reactive.function.client.ClientResponse;
@@ -68,6 +74,14 @@ public abstract class AbstractReactiveWebServerFactoryTests {
 		}
 	}
 
+	@BeforeClass
+	@AfterClass
+	public static void uninstallUrlStreamHandlerFactory() {
+		ReflectionTestUtils.setField(TomcatURLStreamHandlerFactory.class, "instance",
+				null);
+		ReflectionTestUtils.setField(URL.class, "factory", null);
+	}
+
 	protected abstract AbstractReactiveWebServerFactory getFactory();
 
 	@Test

spring-boot/src/test/java/org/springframework/boot/web/servlet/context/ServletWebServerMvcIntegrationTests.java

@@ -17,9 +17,13 @@
 package org.springframework.boot.web.servlet.context;
 
 import java.net.URI;
+import java.net.URL;
 import java.nio.charset.Charset;
 
+import org.apache.catalina.webresources.TomcatURLStreamHandlerFactory;
 import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
 import org.junit.Test;
 
 import org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
@@ -38,6 +42,7 @@ import org.springframework.http.client.ClientHttpRequest;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.http.client.SimpleClientHttpRequestFactory;
 import org.springframework.stereotype.Controller;
+import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.StreamUtils;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
@@ -67,6 +72,14 @@ public class ServletWebServerMvcIntegrationTests {
 		}
 	}
 
+	@BeforeClass
+	@AfterClass
+	public static void uninstallUrlStreamHandlerFactory() {
+		ReflectionTestUtils.setField(TomcatURLStreamHandlerFactory.class, "instance",
+				null);
+		ReflectionTestUtils.setField(URL.class, "factory", null);
+	}
+
 	@Test
 	public void tomcat() throws Exception {
 		this.context = new AnnotationConfigServletWebServerApplicationContext(