Provide a flag to disable XML support

This commit introduces a spring.xml.ignore system property
which when set to true avoid initializing XML infrastructure.

A typical use case is optimizing GraalVM native image footprint
for applications not using XML. In order to be effective, those
classes should be initialized at build time:

- org.springframework.util.DefaultPropertiesPersister
- org.springframework.core.io.support.PropertiesLoaderUtils
- org.springframework.web.servlet.function.support.RouterFunctionMapping
- org.springframework.web.client.RestTemplate
- org.springframework.web.servlet.mvc.method.annotation.ExceptionHandlerExceptionResolver
- org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport
- org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter
- org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter
- org.springframework.http.codec.support.BaseDefaultCodecs
- org.springframework.beans.PropertyEditorRegistrySupport

Closes spring-projectsgh-25151

spring-beans/src/main/java/org/springframework/beans/PropertyEditorRegistrySupport.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -71,6 +71,7 @@
 import org.springframework.beans.propertyeditors.URLEditor;
 import org.springframework.beans.propertyeditors.UUIDEditor;
 import org.springframework.beans.propertyeditors.ZoneIdEditor;
+import org.springframework.core.SpringProperties;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.io.Resource;
 import org.springframework.core.io.support.ResourceArrayPropertyEditor;
@@ -84,13 +85,22 @@
  *
  * @author Juergen Hoeller
  * @author Rob Harrop
+ * @author Sebastien Deleuze
  * @since 1.2.6
  * @see java.beans.PropertyEditorManager
  * @see java.beans.PropertyEditorSupport#setAsText
  * @see java.beans.PropertyEditorSupport#setValue
  */
 public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
+
 	@Nullable
 	private ConversionService conversionService;
 
@@ -208,7 +218,9 @@ private void createDefaultEditors() {
 		this.defaultEditors.put(Currency.class, new CurrencyEditor());
 		this.defaultEditors.put(File.class, new FileEditor());
 		this.defaultEditors.put(InputStream.class, new InputStreamEditor());
-		this.defaultEditors.put(InputSource.class, new InputSourceEditor());
+		if (!shouldIgnoreXml) {
+			this.defaultEditors.put(InputSource.class, new InputSourceEditor());
+		}
 		this.defaultEditors.put(Locale.class, new LocaleEditor());
 		this.defaultEditors.put(Path.class, new PathEditor());
 		this.defaultEditors.put(Pattern.class, new PatternEditor());

spring-core/src/main/java/org/springframework/core/io/support/PropertiesLoaderUtils.java

@@ -24,6 +24,7 @@
 import java.util.Enumeration;
 import java.util.Properties;
 
+import org.springframework.core.SpringProperties;
 import org.springframework.core.io.Resource;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -41,13 +42,21 @@
  *
  * @author Juergen Hoeller
  * @author Rob Harrop
+ * @author Sebastien Deleuze
  * @since 2.0
  * @see PropertiesLoaderSupport
  */
 public abstract class PropertiesLoaderUtils {
 
 	private static final String XML_FILE_EXTENSION = ".xml";
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
 
 	/**
 	 * Load properties from the given EncodedResource,
@@ -88,6 +97,9 @@ static void fillProperties(Properties props, EncodedResource resource, Propertie
 		try {
 			String filename = resource.getResource().getFilename();
 			if (filename != null && filename.endsWith(XML_FILE_EXTENSION)) {
+				if (shouldIgnoreXml) {
+					throw new UnsupportedOperationException("XML support disabled");
+				}
 				stream = resource.getInputStream();
 				persister.loadFromXml(props, stream);
 			}
@@ -133,6 +145,9 @@ public static void fillProperties(Properties props, Resource resource) throws IO
 		try (InputStream is = resource.getInputStream()) {
 			String filename = resource.getFilename();
 			if (filename != null && filename.endsWith(XML_FILE_EXTENSION)) {
+				if (shouldIgnoreXml) {
+					throw new UnsupportedOperationException("XML support disabled");
+				}
 				props.loadFromXML(is);
 			}
 			else {
@@ -180,6 +195,9 @@ public static Properties loadAllProperties(String resourceName, @Nullable ClassL
 			ResourceUtils.useCachesIfNecessary(con);
 			try (InputStream is = con.getInputStream()) {
 				if (resourceName.endsWith(XML_FILE_EXTENSION)) {
+					if (shouldIgnoreXml) {
+						throw new UnsupportedOperationException("XML support disabled");
+					}
 					props.loadFromXML(is);
 				}
 				else {

spring-core/src/main/java/org/springframework/util/DefaultPropertiesPersister.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -23,6 +23,8 @@
 import java.io.Writer;
 import java.util.Properties;
 
+import org.springframework.core.SpringProperties;
+
 /**
  * Default implementation of the {@link PropertiesPersister} interface.
  * Follows the native parsing of {@code java.util.Properties}.
@@ -46,13 +48,22 @@
  * "defaultEncoding" and "fileEncodings" properties).
  *
  * @author Juergen Hoeller
+ * @author Sebastien Deleuze
  * @since 10.03.2004
  * @see java.util.Properties
  * @see java.util.Properties#load
  * @see java.util.Properties#store
  */
 public class DefaultPropertiesPersister implements PropertiesPersister {
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
+
 	@Override
 	public void load(Properties props, InputStream is) throws IOException {
 		props.load(is);
@@ -75,16 +86,25 @@ public void store(Properties props, Writer writer, String header) throws IOExcep
 
 	@Override
 	public void loadFromXml(Properties props, InputStream is) throws IOException {
+		if (shouldIgnoreXml) {
+			throw new UnsupportedOperationException("XML support disabled");
+		}
 		props.loadFromXML(is);
 	}
 
 	@Override
 	public void storeToXml(Properties props, OutputStream os, String header) throws IOException {
+		if (shouldIgnoreXml) {
+			throw new UnsupportedOperationException("XML support disabled");
+		}
 		props.storeToXML(os, header);
 	}
 
 	@Override
 	public void storeToXml(Properties props, OutputStream os, String header, String encoding) throws IOException {
+		if (shouldIgnoreXml) {
+			throw new UnsupportedOperationException("XML support disabled");
+		}
 		props.storeToXML(os, header, encoding);
 	}
 

spring-web/src/main/java/org/springframework/http/codec/support/BaseDefaultCodecs.java

@@ -21,6 +21,7 @@
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.core.SpringProperties;
 import org.springframework.core.codec.AbstractDataBufferDecoder;
 import org.springframework.core.codec.ByteArrayDecoder;
 import org.springframework.core.codec.ByteArrayEncoder;
@@ -70,6 +71,13 @@
  */
 class BaseDefaultCodecs implements CodecConfigurer.DefaultCodecs, CodecConfigurer.DefaultCodecConfig {
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
 	static final boolean jackson2Present;
 
 	private static final boolean jackson2SmilePresent;
@@ -284,7 +292,7 @@ private void initCodec(@Nullable Object codec) {
 					((AbstractJackson2Decoder) codec).setMaxInMemorySize(size);
 				}
 			}
-			if (jaxb2Present) {
+			if (jaxb2Present && !shouldIgnoreXml) {
 				if (codec instanceof Jaxb2XmlDecoder) {
 					((Jaxb2XmlDecoder) codec).setMaxInMemorySize(size);
 				}
@@ -353,7 +361,7 @@ final List<HttpMessageReader<?>> getObjectReaders() {
 			addCodec(readers, new DecoderHttpMessageReader<>(this.jackson2SmileDecoder != null ?
 					(Jackson2SmileDecoder) this.jackson2SmileDecoder : new Jackson2SmileDecoder()));
 		}
-		if (jaxb2Present) {
+		if (jaxb2Present && !shouldIgnoreXml) {
 			addCodec(readers, new DecoderHttpMessageReader<>(this.jaxb2Decoder != null ?
 					(Jaxb2XmlDecoder) this.jaxb2Decoder : new Jaxb2XmlDecoder()));
 		}
@@ -449,7 +457,7 @@ final List<HttpMessageWriter<?>> getBaseObjectWriters() {
 			writers.add(new EncoderHttpMessageWriter<>(this.jackson2SmileEncoder != null ?
 					(Jackson2SmileEncoder) this.jackson2SmileEncoder : new Jackson2SmileEncoder()));
 		}
-		if (jaxb2Present) {
+		if (jaxb2Present && !shouldIgnoreXml) {
 			writers.add(new EncoderHttpMessageWriter<>(this.jaxb2Encoder != null ?
 					(Jaxb2XmlEncoder) this.jaxb2Encoder : new Jaxb2XmlEncoder()));
 		}

spring-web/src/main/java/org/springframework/http/converter/support/AllEncompassingFormHttpMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.http.converter.support;
 
+import org.springframework.core.SpringProperties;
 import org.springframework.http.converter.FormHttpMessageConverter;
 import org.springframework.http.converter.json.GsonHttpMessageConverter;
 import org.springframework.http.converter.json.JsonbHttpMessageConverter;
@@ -32,10 +33,18 @@
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
+ * @author Sebastien Deleuze
  * @since 3.2
  */
 public class AllEncompassingFormHttpMessageConverter extends FormHttpMessageConverter {
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
 	private static final boolean jaxb2Present;
 
 	private static final boolean jackson2Present;
@@ -61,15 +70,17 @@ public class AllEncompassingFormHttpMessageConverter extends FormHttpMessageConv
 
 
 	public AllEncompassingFormHttpMessageConverter() {
-		try {
-			addPartConverter(new SourceHttpMessageConverter<>());
-		}
-		catch (Error err) {
-			// Ignore when no TransformerFactory implementation is available
-		}
-
-		if (jaxb2Present && !jackson2XmlPresent) {
-			addPartConverter(new Jaxb2RootElementHttpMessageConverter());
+		if (!shouldIgnoreXml) {
+			try {
+				addPartConverter(new SourceHttpMessageConverter<>());
+			}
+			catch (Error err) {
+				// Ignore when no TransformerFactory implementation is available
+			}
+
+			if (jaxb2Present) {
+				addPartConverter(new Jaxb2RootElementHttpMessageConverter());
+			}
 		}
 
 		if (jackson2Present) {
@@ -82,7 +93,7 @@ else if (jsonbPresent) {
 			addPartConverter(new JsonbHttpMessageConverter());
 		}
 
-		if (jackson2XmlPresent) {
+		if (jackson2XmlPresent && !shouldIgnoreXml) {
 			addPartConverter(new MappingJackson2XmlHttpMessageConverter());
 		}
 

spring-web/src/main/java/org/springframework/web/client/RestTemplate.java

@@ -29,6 +29,7 @@
 import java.util.stream.Stream;
 
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.core.SpringProperties;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
@@ -82,6 +83,7 @@
  * @author Roy Clarkson
  * @author Juergen Hoeller
  * @author Sam Brannen
+ * @author Sebastien Deleuze
  * @since 3.0
  * @see HttpMessageConverter
  * @see RequestCallback
@@ -90,6 +92,13 @@
  */
 public class RestTemplate extends InterceptingHttpAccessor implements RestOperations {
 
+	/**
+	 * Boolean flag controlled by a {@code spring.xml.ignore} system property that instructs Spring to
+	 * ignore XML, i.e. to not initialize the XML-related infrastructure.
+	 * <p>The default is "false".
+	 */
+	private static final boolean shouldIgnoreXml = SpringProperties.getFlag("spring.xml.ignore");
+
 	private static final boolean romePresent;
 
 	private static final boolean jaxb2Present;
@@ -138,11 +147,13 @@ public RestTemplate() {
 		this.messageConverters.add(new ByteArrayHttpMessageConverter());
 		this.messageConverters.add(new StringHttpMessageConverter());
 		this.messageConverters.add(new ResourceHttpMessageConverter(false));
-		try {
-			this.messageConverters.add(new SourceHttpMessageConverter<>());
-		}
-		catch (Error err) {
-			// Ignore when no TransformerFactory implementation is available
+		if (!shouldIgnoreXml) {
+			try {
+				this.messageConverters.add(new SourceHttpMessageConverter<>());
+			}
+			catch (Error err) {
+				// Ignore when no TransformerFactory implementation is available
+			}
 		}
 		this.messageConverters.add(new AllEncompassingFormHttpMessageConverter());
 
@@ -151,11 +162,13 @@ public RestTemplate() {
 			this.messageConverters.add(new RssChannelHttpMessageConverter());
 		}
 
-		if (jackson2XmlPresent) {
-			this.messageConverters.add(new MappingJackson2XmlHttpMessageConverter());
-		}
-		else if (jaxb2Present) {
-			this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
+		if (!shouldIgnoreXml) {
+			if (jackson2XmlPresent) {
+				this.messageConverters.add(new MappingJackson2XmlHttpMessageConverter());
+			}
+			else if (jaxb2Present) {
+				this.messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
+			}
 		}
 
 		if (jackson2Present) {