Support custom XmlFactory in Jackson2ObjectMapperBuilder

Closes gh-22428

Author: sdeleuze

spring-web/src/main/java/org/springframework/http/converter/json/Jackson2ObjectMapperBuilder.java

@@ -614,8 +614,8 @@ public <T extends ObjectMapper> T build() {
 		ObjectMapper mapper;
 		if (this.createXmlMapper) {
 			mapper = (this.defaultUseWrapper != null ?
-					new XmlObjectMapperInitializer().create(this.defaultUseWrapper) :
-					new XmlObjectMapperInitializer().create());
+					new XmlObjectMapperInitializer().create(this.defaultUseWrapper, this.factory) :
+					new XmlObjectMapperInitializer().create(this.factory));
 		}
 		else {
 			mapper = (this.factory != null ? new ObjectMapper(this.factory) : new ObjectMapper());
@@ -839,14 +839,24 @@ public static Jackson2ObjectMapperBuilder cbor() {
 
 	private static class XmlObjectMapperInitializer {
 
-		public ObjectMapper create() {
-			return new XmlMapper(StaxUtils.createDefensiveInputFactory());
+		public ObjectMapper create(@Nullable JsonFactory factory) {
+			if (factory != null) {
+				return new XmlMapper((XmlFactory) factory);
+			}
+			else {
+				return new XmlMapper(StaxUtils.createDefensiveInputFactory());
+			}
 		}
 
-		public ObjectMapper create(boolean defaultUseWrapper) {
+		public ObjectMapper create(boolean defaultUseWrapper, @Nullable JsonFactory factory) {
 			JacksonXmlModule module = new JacksonXmlModule();
 			module.setDefaultUseWrapper(defaultUseWrapper);
-			return new XmlMapper(new XmlFactory(StaxUtils.createDefensiveInputFactory()), module);
+			if (factory != null) {
+				return new XmlMapper((XmlFactory) factory, module);
+			}
+			else {
+				return new XmlMapper(new XmlFactory(StaxUtils.createDefensiveInputFactory()), module);
+			}
 		}
 	}
 

spring-web/src/test/java/org/springframework/http/converter/json/Jackson2ObjectMapperBuilderTests.java

@@ -71,6 +71,7 @@
 import com.fasterxml.jackson.databind.type.SimpleType;
 import com.fasterxml.jackson.dataformat.cbor.CBORFactory;
 import com.fasterxml.jackson.dataformat.smile.SmileFactory;
+import com.fasterxml.jackson.dataformat.xml.XmlFactory;
 import com.fasterxml.jackson.dataformat.xml.XmlMapper;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import kotlin.ranges.IntRange;
@@ -480,6 +481,14 @@ public void xmlMapper() {
 		assertEquals(XmlMapper.class, objectMapper.getClass());
 	}
 
+	@Test  // gh-22428
+	public void xmlMapperAndCustomFactory() {
+		ObjectMapper objectMapper = Jackson2ObjectMapperBuilder.xml().factory(new MyXmlFactory()).build();
+		assertNotNull(objectMapper);
+		assertEquals(XmlMapper.class, objectMapper.getClass());
+		assertEquals(MyXmlFactory.class, objectMapper.getFactory().getClass());
+	}
+
 	@Test
 	public void createXmlMapper() {
 		Jackson2ObjectMapperBuilder builder = Jackson2ObjectMapperBuilder.json().indentOutput(true);
@@ -667,4 +676,7 @@ public void setOffsetDateTime(OffsetDateTime offsetDateTime) {
 
 	}
 
+	public static class MyXmlFactory extends XmlFactory {
+	}
+
 }