Fix test ordering problems by always clearing URL stream handler factory

Closes gh-19349

Author: wilkinsona

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactoryTests.java

@@ -19,7 +19,6 @@
 import java.io.File;
 import java.io.IOException;
 import java.net.URISyntaxException;
-import java.net.URL;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
@@ -54,7 +53,6 @@
 import org.apache.catalina.startup.Tomcat;
 import org.apache.catalina.util.CharsetMapper;
 import org.apache.catalina.valves.RemoteIpValve;
-import org.apache.catalina.webresources.TomcatURLStreamHandlerFactory;
 import org.apache.jasper.servlet.JspServlet;
 import org.apache.tomcat.JarScanFilter;
 import org.apache.tomcat.JarScanType;
@@ -75,7 +73,6 @@
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
-import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.FileSystemUtils;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
@@ -108,8 +105,6 @@ protected TomcatServletWebServerFactory getFactory() {
 
 	@After
 	public void restoreTccl() {
-		ReflectionTestUtils.setField(TomcatURLStreamHandlerFactory.class, "instance", null);
-		ReflectionTestUtils.setField(URL.class, "factory", null);
 		Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
 	}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/server/AbstractServletWebServerFactoryTests.java

@@ -67,6 +67,7 @@
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;
 
+import org.apache.catalina.webresources.TomcatURLStreamHandlerFactory;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.entity.InputStreamFactory;
 import org.apache.http.client.protocol.HttpClientContext;
@@ -111,6 +112,7 @@
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.FileCopyUtils;
 import org.springframework.util.SocketUtils;
 import org.springframework.util.StreamUtils;
@@ -161,6 +163,15 @@ public void tearDown() {
 		}
 	}
 
+	@After
+	public void clearUrlStreamHandlerFactory() {
+		if (ClassUtils.isPresent("org.apache.catalina.webresources.TomcatURLStreamHandlerFactory",
+				getClass().getClassLoader())) {
+			ReflectionTestUtils.setField(TomcatURLStreamHandlerFactory.class, "instance", null);
+			ReflectionTestUtils.setField(URL.class, "factory", null);
+		}
+	}
+
 	@Test
 	public void startServlet() throws Exception {
 		AbstractServletWebServerFactory factory = getFactory();