Fixed Jaxb2CollectionHttpMessageConverterTests

- Added Woodstox before Aalto in the spring-web build, so that Woodstox
   is used as StAX implementation, and not the less featured Aalto.
 - Hardcoded Aalto dependency in XmlEventDecoder, instead of relying on
   the StAX XMLInputFactory.

build.gradle

@@ -77,6 +77,7 @@ configure(allprojects) { project ->
 	ext.tomcatVersion        = "8.5.3"
 	ext.tyrusVersion         = "1.13"
 	ext.undertowVersion      = "1.4.0.CR3"
+	ext.woodstoxVersion      = "5.0.2"
 	ext.xmlunitVersion       = "1.6"
 	ext.xstreamVersion       = "1.4.9"
 
@@ -369,7 +370,7 @@ project("spring-core") {
 		optional("io.netty:netty-buffer:${nettyVersion}")
 		testCompile("org.apache.tomcat.embed:tomcat-embed-core:${tomcatVersion}")
 		testCompile("xmlunit:xmlunit:${xmlunitVersion}")
-		testCompile("com.fasterxml.woodstox:woodstox-core:5.0.2") {
+		testCompile("com.fasterxml.woodstox:woodstox-core:${woodstoxVersion}") {
 			exclude group: "stax", module: "stax-api"
 		}
 	}
@@ -691,6 +692,9 @@ project("spring-web") {
 		optional("io.reactivex:rxjava:${rxJavaVersion}")
 		optional("io.undertow:undertow-core:1.3.20.Final")
 		optional("io.netty:netty-buffer:${nettyVersion}") // Temporarily for JsonObjectDecoder
+	  	optional("com.fasterxml.woodstox:woodstox-core:${woodstoxVersion}") { // woodstox before aalto
+			exclude group: "stax", module: "stax-api"
+		}
 		optional("com.fasterxml:aalto-xml:1.0.0")
 		optional("org.apache.httpcomponents:httpclient:${httpclientVersion}")
 		optional("org.apache.httpcomponents:httpasyncclient:${httpasyncVersion}")
@@ -725,6 +729,7 @@ project("spring-web") {
 		testCompile("org.eclipse.jetty:jetty-server:${jettyVersion}")
 		testCompile("org.eclipse.jetty:jetty-servlet:${jettyVersion}")
 		testCompile("com.squareup.okhttp3:mockwebserver:3.0.1")
+
 	}
 }
 

spring-web/src/main/java/org/springframework/http/codec/xml/XmlEventDecoder.java

@@ -30,6 +30,7 @@ import com.fasterxml.aalto.AsyncByteBufferFeeder;
 import com.fasterxml.aalto.AsyncXMLInputFactory;
 import com.fasterxml.aalto.AsyncXMLStreamReader;
 import com.fasterxml.aalto.evt.EventAllocatorImpl;
+import com.fasterxml.aalto.stax.InputFactoryImpl;
 import org.reactivestreams.Publisher;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -116,8 +117,7 @@ public class XmlEventDecoder extends AbstractDecoder<XMLEvent> {
 	private static class AaltoDataBufferToXmlEvent
 			implements Function<DataBuffer, Publisher<? extends XMLEvent>> {
 
-		private static final AsyncXMLInputFactory inputFactory =
-				(AsyncXMLInputFactory) XmlEventDecoder.inputFactory;
+		private static final AsyncXMLInputFactory inputFactory = new InputFactoryImpl();
 
 		private final AsyncXMLStreamReader<AsyncByteBufferFeeder> streamReader =
 				inputFactory.createAsyncForByteBuffer();