XmlEventDecoder uses common defensive XMLInputFactory (now in StaxUtils)

Issue: SPR-15797

spring-core/src/main/java/org/springframework/util/xml/StaxUtils.java

@@ -20,6 +20,8 @@ import java.util.List;
 import javax.xml.stream.XMLEventFactory;
 import javax.xml.stream.XMLEventReader;
 import javax.xml.stream.XMLEventWriter;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLResolver;
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.stream.XMLStreamWriter;
@@ -33,13 +35,15 @@ import org.xml.sax.ContentHandler;
 import org.xml.sax.XMLReader;
 
 import org.springframework.lang.Nullable;
+import org.springframework.util.StreamUtils;
 
 /**
- * Convenience methods for working with the StAX API. Partly historic due to JAXP 1.3 compatibility;
- * as of Spring 4.0, relying on JAXP 1.4 as included in JDK 1.6 and higher.
+ * Convenience methods for working with the StAX API. Partly historic due to JAXP 1.3
+ * compatibility; as of Spring 4.0, relying on JAXP 1.4 as included in JDK 1.6 and higher.
  *
- * <p>In particular, methods for using StAX ({@code javax.xml.stream}) in combination with the TrAX API
- * ({@code javax.xml.transform}), and converting StAX readers/writers into SAX readers/handlers and vice-versa.
+ * <p>In particular, methods for using StAX ({@code javax.xml.stream}) in combination with
+ * the TrAX API ({@code javax.xml.transform}), and converting StAX readers/writers into SAX
+ * readers/handlers and vice-versa.
  *
  * @author Arjen Poutsma
  * @author Juergen Hoeller
@@ -47,6 +51,24 @@ import org.springframework.lang.Nullable;
  */
 public abstract class StaxUtils {
 
+	private static final XMLResolver NO_OP_XML_RESOLVER =
+			(publicID, systemID, base, ns) -> StreamUtils.emptyInput();
+
+
+	/**
+	 * Create an {@link XMLInputFactory} with Spring's defensive setup,
+	 * i.e. no support for the resolution of DTDs and external entities.
+	 * @return a new input factory to use
+	 * @since 5.0
+	 */
+	public static XMLInputFactory createDefensiveInputFactory() {
+		XMLInputFactory inputFactory = XMLInputFactory.newInstance();
+		inputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
+		inputFactory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
+		inputFactory.setXMLResolver(NO_OP_XML_RESOLVER);
+		return inputFactory;
+	}
+
 	/**
 	 * Create a JAXP 1.4 {@link StAXSource} for the given {@link XMLStreamReader}.
 	 * @param streamReader the StAX stream reader
@@ -57,7 +79,7 @@ public abstract class StaxUtils {
 	}
 
 	/**
-	 * Create a JAXP 1.4 a {@link StAXSource} for the given {@link XMLEventReader}.
+	 * Create a JAXP 1.4 {@link StAXSource} for the given {@link XMLEventReader}.
 	 * @param eventReader the StAX event reader
 	 * @return a source wrapping the {@code eventReader}
 	 */

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

@@ -44,6 +44,7 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
+import org.springframework.util.xml.StaxUtils;
 
 /**
  * Decodes a {@link DataBuffer} stream into a stream of {@link XMLEvent}s.
@@ -77,7 +78,7 @@ import org.springframework.util.MimeTypeUtils;
  */
 public class XmlEventDecoder extends AbstractDecoder<XMLEvent> {
 
-	private static final XMLInputFactory inputFactory = XMLInputFactory.newInstance();
+	private static final XMLInputFactory inputFactory = StaxUtils.createDefensiveInputFactory();
 
 	private static final boolean aaltoPresent = ClassUtils.isPresent(
 			"com.fasterxml.aalto.AsyncXMLStreamReader", XmlEventDecoder.class.getClassLoader());

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

@@ -26,8 +26,6 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.TimeZone;
-import javax.xml.stream.XMLInputFactory;
-import javax.xml.stream.XMLResolver;
 
 import com.fasterxml.jackson.annotation.JsonFilter;
 import com.fasterxml.jackson.annotation.JsonInclude;
@@ -62,8 +60,8 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
-import org.springframework.util.StreamUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.util.xml.StaxUtils;
 
 /**
  * A builder used to create {@link ObjectMapper} instances with a fluent API.
@@ -827,38 +825,27 @@ public class Jackson2ObjectMapperBuilder {
 	private static class XmlObjectMapperInitializer {
 
 		public ObjectMapper create() {
-			return new XmlMapper(xmlInputFactory());
+			return new XmlMapper(StaxUtils.createDefensiveInputFactory());
 		}
 
 		public ObjectMapper create(boolean defaultUseWrapper) {
 			JacksonXmlModule module = new JacksonXmlModule();
 			module.setDefaultUseWrapper(defaultUseWrapper);
-			return new XmlMapper(new XmlFactory(xmlInputFactory()), module);
+			return new XmlMapper(new XmlFactory(StaxUtils.createDefensiveInputFactory()), module);
 		}
-
-		private static XMLInputFactory xmlInputFactory() {
-			XMLInputFactory inputFactory = XMLInputFactory.newInstance();
-			inputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
-			inputFactory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
-			inputFactory.setXMLResolver(NO_OP_XML_RESOLVER);
-			return inputFactory;
-		}
-
-		private static final XMLResolver NO_OP_XML_RESOLVER = new XMLResolver() {
-			@Override
-			public Object resolveEntity(String publicID, String systemID, String base, String ns) {
-				return StreamUtils.emptyInput();
-			}
-		};
 	}
 
+
 	private static class SmileFactoryInitializer {
+
 		public JsonFactory create() {
 			return new SmileFactory();
 		}
 	}
 
+
 	private static class CborFactoryInitializer {
+
 		public JsonFactory create() {
 			return new CBORFactory();
 		}

spring-web/src/main/java/org/springframework/http/converter/xml/Jaxb2CollectionHttpMessageConverter.java

@@ -31,7 +31,6 @@ import javax.xml.bind.Unmarshaller;
 import javax.xml.bind.annotation.XmlRootElement;
 import javax.xml.bind.annotation.XmlType;
 import javax.xml.stream.XMLInputFactory;
-import javax.xml.stream.XMLResolver;
 import javax.xml.stream.XMLStreamException;
 import javax.xml.stream.XMLStreamReader;
 import javax.xml.transform.Result;
@@ -47,7 +46,7 @@ import org.springframework.http.converter.HttpMessageNotReadableException;
 import org.springframework.http.converter.HttpMessageNotWritableException;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ReflectionUtils;
-import org.springframework.util.StreamUtils;
+import org.springframework.util.xml.StaxUtils;
 
 /**
  * An {@code HttpMessageConverter} that can read XML collections using JAXB2.
@@ -242,25 +241,15 @@ public class Jaxb2CollectionHttpMessageConverter<T extends Collection>
 	}
 
 	/**
-	 * Create a {@code XMLInputFactory} that this converter will use to create {@link
-	 * javax.xml.stream.XMLStreamReader} and {@link javax.xml.stream.XMLEventReader} objects.
+	 * Create an {@code XMLInputFactory} that this converter will use to create
+	 * {@link javax.xml.stream.XMLStreamReader} and {@link javax.xml.stream.XMLEventReader}
+	 * objects.
 	 * <p>Can be overridden in subclasses, adding further initialization of the factory.
 	 * The resulting factory is cached, so this method will only be called once.
+	 * @see StaxUtils#createDefensiveInputFactory()
 	 */
 	protected XMLInputFactory createXmlInputFactory() {
-		XMLInputFactory inputFactory = XMLInputFactory.newInstance();
-		inputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
-		inputFactory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
-		inputFactory.setXMLResolver(NO_OP_XML_RESOLVER);
-		return inputFactory;
+		return StaxUtils.createDefensiveInputFactory();
 	}
 
-
-	private static final XMLResolver NO_OP_XML_RESOLVER = new XMLResolver() {
-		@Override
-		public Object resolveEntity(String publicID, String systemID, String base, String ns) {
-			return StreamUtils.emptyInput();
-		}
-	};
-
 }

spring-web/src/main/java/org/springframework/http/converter/xml/SourceHttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,7 +66,13 @@ import org.springframework.util.StreamUtils;
  */
 public class SourceHttpMessageConverter<T extends Source> extends AbstractHttpMessageConverter<T> {
 
-	private static final Set<Class<?>> SUPPORTED_CLASSES = new HashSet<>(5);
+	private static final EntityResolver NO_OP_ENTITY_RESOLVER =
+			(publicId, systemId) -> new InputSource(new StringReader(""));
+
+	private static final XMLResolver NO_OP_XML_RESOLVER =
+			(publicID, systemID, base, ns) -> StreamUtils.emptyInput();
+
+	private static final Set<Class<?>> SUPPORTED_CLASSES = new HashSet<>(8);
 
 	static {
 		SUPPORTED_CLASSES.add(DOMSource.class);
@@ -279,19 +285,4 @@ public class SourceHttpMessageConverter<T extends Source> extends AbstractHttpMe
 		}
 	}
 
-
-	private static final EntityResolver NO_OP_ENTITY_RESOLVER = new EntityResolver() {
-		@Override
-		public InputSource resolveEntity(String publicId, String systemId) {
-			return new InputSource(new StringReader(""));
-		}
-	};
-
-	private static final XMLResolver NO_OP_XML_RESOLVER = new XMLResolver() {
-		@Override
-		public Object resolveEntity(String publicID, String systemID, String base, String ns) {
-			return StreamUtils.emptyInput();
-		}
-	};
-
 }