Remove Undertow-specific support and testing

Undertow does not support Servlet 6.1, we need to remove compatibility
tests as well as Undertow-specific classes for WebSocket and reactive
support.

Closes gh-35354

spring-web/src/test/java/org/springframework/http/server/reactive/CookieIntegrationTests.java

@@ -31,7 +31,6 @@ import org.springframework.web.client.RestTemplate;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.AbstractHttpHandlerIntegrationTests;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.JettyHttpServer;
-import org.springframework.web.testfixture.http.server.reactive.bootstrap.UndertowHttpServer;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assumptions.assumeFalse;
@@ -80,7 +79,6 @@ class CookieIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	@ParameterizedHttpServerTest
 	public void partitionedAttributeTest(HttpServer httpServer) throws Exception {
-		assumeFalse(httpServer instanceof UndertowHttpServer, "Undertow does not support Partitioned cookies");
 		assumeFalse(httpServer instanceof JettyHttpServer, "Jetty does not support Servlet 6.1 yet");
 		startServer(httpServer);
 
@@ -100,8 +98,6 @@ class CookieIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	@ParameterizedHttpServerTest
 	public void cookiesWithSameNameTest(HttpServer httpServer) throws Exception {
-		assumeFalse(httpServer instanceof UndertowHttpServer, "Bug in Undertow in Cookies with same name handling");
-
 		startServer(httpServer);
 
 		URI url = new URI("http://localhost:" + port);

spring-web/src/test/java/org/springframework/http/server/reactive/DefaultServerHttpRequestBuilderTests.java

@@ -21,7 +21,6 @@ import java.util.stream.Stream;
 
 import io.netty.handler.codec.http.DefaultHttpHeaders;
 import io.netty.handler.codec.http.ReadOnlyHttpHeaders;
-import io.undertow.util.HeaderMap;
 import org.apache.tomcat.util.http.MimeHeaders;
 import org.eclipse.jetty.http.HttpFields;
 import org.junit.jupiter.params.ParameterizedTest;
@@ -102,7 +101,6 @@ class DefaultServerHttpRequestBuilderTests {
 				initHeader("Map", CollectionUtils.toMultiValueMap(new LinkedCaseInsensitiveMap<>(8, Locale.ENGLISH))),
 				initHeader("Netty", new Netty4HeadersAdapter(new DefaultHttpHeaders())),
 				initHeader("Tomcat", new TomcatHeadersAdapter(new MimeHeaders())),
-				initHeader("Undertow", new UndertowHeadersAdapter(new HeaderMap())),
 				initHeader("Jetty", new JettyHeadersAdapter(HttpFields.build())),
 				//immutable versions of some headers
 				argumentSet("Netty immutable", new Netty4HeadersAdapter(new ReadOnlyHttpHeaders(false,

spring-web/src/test/java/org/springframework/http/server/reactive/HeadersAdaptersTests.java

@@ -29,8 +29,6 @@ import java.util.function.Function;
 import java.util.stream.Stream;
 
 import io.netty.handler.codec.http.DefaultHttpHeaders;
-import io.undertow.util.HeaderMap;
-import io.undertow.util.HttpString;
 import org.apache.hc.client5.http.classic.methods.HttpGet;
 import org.apache.tomcat.util.http.MimeHeaders;
 import org.eclipse.jetty.http.HttpFields;
@@ -273,7 +271,6 @@ class HeadersAdaptersTests {
 				argumentSet("Map", CollectionUtils.toMultiValueMap(new LinkedCaseInsensitiveMap<>(8, Locale.ENGLISH))),
 				argumentSet("Netty", new Netty4HeadersAdapter(new DefaultHttpHeaders())),
 				argumentSet("Tomcat", new TomcatHeadersAdapter(new MimeHeaders())),
-				argumentSet("Undertow", new UndertowHeadersAdapter(new HeaderMap())),
 				argumentSet("Jetty", new JettyHeadersAdapter(HttpFields.build())),
 				argumentSet("HttpComponents", new HttpComponentsHeadersAdapter(new HttpGet("https://example.com")))
 		);
@@ -291,8 +288,6 @@ class HeadersAdaptersTests {
 				argumentSet("Netty", new Netty4HeadersAdapter(withHeaders(new DefaultHttpHeaders(), h -> h::add))),
 				argumentSet("Tomcat", new TomcatHeadersAdapter(withHeaders(new MimeHeaders(),
 						h -> (k, v) -> h.addValue(k).setString(v)))),
-				argumentSet("Undertow", new UndertowHeadersAdapter(withHeaders(new HeaderMap(),
-						h -> (k, v) -> h.add(HttpString.tryFromString(k), v)))),
 				argumentSet("Jetty", new JettyHeadersAdapter(withHeaders(HttpFields.build(), h -> h::add))),
 				argumentSet("HttpComponents", new HttpComponentsHeadersAdapter(withHeaders(new HttpGet("https://example.com"),
 						h -> h::addHeader)))

spring-web/src/test/java/org/springframework/http/server/reactive/ZeroCopyIntegrationTests.java

@@ -32,7 +32,6 @@ import org.springframework.web.testfixture.http.server.reactive.bootstrap.Abstra
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.HttpServer;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.JettyCoreHttpServer;
 import org.springframework.web.testfixture.http.server.reactive.bootstrap.ReactorHttpServer;
-import org.springframework.web.testfixture.http.server.reactive.bootstrap.UndertowHttpServer;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assumptions.assumeTrue;
@@ -55,7 +54,7 @@ class ZeroCopyIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	@ParameterizedHttpServerTest
 	void zeroCopy(HttpServer httpServer) throws Exception {
-		assumeTrue(httpServer instanceof ReactorHttpServer || httpServer instanceof UndertowHttpServer ||
+		assumeTrue(httpServer instanceof ReactorHttpServer ||
 				httpServer instanceof JettyCoreHttpServer, "Zero-copy does not support Servlet");
 
 		startServer(httpServer);

spring-web/src/test/java/org/springframework/web/multipart/support/StandardMultipartHttpServletRequestTests.java

@@ -123,15 +123,6 @@ class StandardMultipartHttpServletRequestTests {
 				.isThrownBy(() -> requestWithException(ex)).withCause(ex);
 	}
 
-	@Test  // gh-32549
-	void undertowRequestTooBigException() {
-		IOException ex = new IOException("Connection terminated as request was larger than 10000");
-
-		assertThatExceptionOfType(MaxUploadSizeExceededException.class)
-				.isThrownBy(() -> requestWithException(ex)).withCause(ex);
-	}
-
-
 	private static StandardMultipartHttpServletRequest requestWithPart(String name, String disposition, String content) {
 		MockHttpServletRequest request = new MockHttpServletRequest();
 		MockPart part = new MockPart(name, null, content.getBytes(StandardCharsets.UTF_8));
@@ -150,14 +141,4 @@ class StandardMultipartHttpServletRequestTests {
 		return new StandardMultipartHttpServletRequest(request);
 	}
 
-	private static StandardMultipartHttpServletRequest requestWithException(IOException ex) {
-		MockHttpServletRequest request = new MockHttpServletRequest() {
-			@Override
-			public Collection<Part> getParts() throws IOException {
-				throw ex;
-			}
-		};
-		return new StandardMultipartHttpServletRequest(request);
-	}
-
 }