Refactored CodecConfigurer creation for clearer subpackage interdependencies

Includes redeclaration of CodecConfigurer.DefaultCodecs without concrete Jackson decoder/encoder references in order to avoid hard Jackson dependency.

Issue: SPR-16064

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

@@ -35,17 +35,15 @@ import org.springframework.core.codec.Encoder;
  */
 public interface ClientCodecConfigurer extends CodecConfigurer {
 
-
 	@Override
 	ClientDefaultCodecs defaultCodecs();
 
 
 	/**
-	 * Creates a new instance of the {@code ClientCodecConfigurer}.
-	 * @return the created instance
+	 * Create a new instance of the {@code ClientCodecConfigurer}.
 	 */
 	static ClientCodecConfigurer create() {
-		return new DefaultClientCodecConfigurer();
+		return CodecConfigurerFactory.create(ClientCodecConfigurer.class);
 	}
 
 
@@ -71,6 +69,7 @@ public interface ClientCodecConfigurer extends CodecConfigurer {
 		void serverSentEventDecoder(Decoder<?> decoder);
 	}
 
+
 	/**
 	 * Registry and container for multipart HTTP message writers.
 	 */

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

@@ -20,8 +20,6 @@ import java.util.List;
 
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
-import org.springframework.http.codec.json.Jackson2JsonDecoder;
-import org.springframework.http.codec.json.Jackson2JsonEncoder;
 
 /**
  * Defines a common interface for configuring either client or server HTTP
@@ -73,15 +71,16 @@ public interface CodecConfigurer {
 		/**
 		 * Override the default Jackson JSON {@code Decoder}.
 		 * @param decoder the decoder instance to use
+		 * @see org.springframework.http.codec.json.Jackson2JsonDecoder
 		 */
-		void jackson2JsonDecoder(Jackson2JsonDecoder decoder);
+		void jackson2JsonDecoder(Decoder<?> decoder);
 
 		/**
 		 * Override the default Jackson JSON {@code Encoder}.
 		 * @param encoder the encoder instance to use
+		 * @see org.springframework.http.codec.json.Jackson2JsonEncoder
 		 */
-		void jackson2JsonEncoder(Jackson2JsonEncoder encoder);
-
+		void jackson2JsonEncoder(Encoder<?> encoder);
 	}
 
 
@@ -119,6 +118,6 @@ public interface CodecConfigurer {
 		 * @param writer the writer to add
 		 */
 		void writer(HttpMessageWriter<?> writer);
-
 	}
+
 }

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

@@ -0,0 +1,71 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.http.codec;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.support.PropertiesLoaderUtils;
+import org.springframework.util.ClassUtils;
+
+/**
+ * Internal delegate for loading the default codec configurer class names.
+ * Models a loose relationship with the default implementations in the support
+ * package, literally only needing to know the default class name to use.
+ *
+ * @author Juergen Hoeller
+ * @since 5.0.1
+ * @see ClientCodecConfigurer#create()
+ * @see ServerCodecConfigurer#create()
+ */
+class CodecConfigurerFactory {
+
+	private static final String DEFAULT_CONFIGURERS_PATH = "CodecConfigurer.properties";
+
+	private static final Map<Class<?>, Class<?>> defaultCodecConfigurers = new HashMap<>(4);
+
+	static {
+		try {
+			Properties props = PropertiesLoaderUtils.loadProperties(
+					new ClassPathResource(DEFAULT_CONFIGURERS_PATH, CodecConfigurerFactory.class));
+			for (String ifcName : props.stringPropertyNames()) {
+				String implName = props.getProperty(ifcName);
+				Class<?> ifc = ClassUtils.forName(ifcName, CodecConfigurerFactory.class.getClassLoader());
+				Class<?> impl = ClassUtils.forName(implName, CodecConfigurerFactory.class.getClassLoader());
+				defaultCodecConfigurers.put(ifc, impl);
+			}
+		}
+		catch (IOException | ClassNotFoundException ex) {
+			throw new IllegalStateException(ex);
+		}
+	}
+
+
+	@SuppressWarnings("unchecked")
+	public static <T extends CodecConfigurer> T create(Class<T> ifc) {
+		Class<?> impl = defaultCodecConfigurers.get(ifc);
+		if (impl == null) {
+			throw new IllegalStateException("No default codec configurer found for " + ifc);
+		}
+		return (T) BeanUtils.instantiateClass(impl);
+	}
+
+}

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

@@ -39,11 +39,10 @@ public interface ServerCodecConfigurer extends CodecConfigurer {
 
 
 	/**
-	 * Creates a new instance of the {@code ServerCodecConfigurer}.
-	 * @return the created instance
+	 * Create a new instance of the {@code ServerCodecConfigurer}.
 	 */
 	static ServerCodecConfigurer create() {
-		return new DefaultServerCodecConfigurer();
+		return CodecConfigurerFactory.create(ServerCodecConfigurer.class);
 	}
 
 

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

@@ -18,7 +18,6 @@ package org.springframework.http.codec;
 
 import java.time.Duration;
 
-import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.lang.Nullable;
 
 /**
@@ -167,10 +166,10 @@ public class ServerSentEvent<T> {
         Builder<T> comment(String comment);
 
 		/**
-		 * Set the value of the {@code data} field. If the {@code data} argument is a
-		 * multi-line {@code String}, it will be turned into multiple {@code data} field lines
-		 * as defined in the Server-Sent Events W3C recommendation. If {@code data} is not a
-		 * String, it will be {@linkplain Jackson2JsonEncoder encoded} into JSON.
+		 * Set the value of the {@code data} field. If the {@code data} argument is a multi-line
+		 * {@code String}, it will be turned into multiple {@code data} field lines as defined
+		 * in the Server-Sent Events W3C recommendation. If {@code data} is not a String, it will
+		 * be {@linkplain org.springframework.http.codec.json.Jackson2JsonEncoder encoded} into JSON.
 		 * @param data the value of the data field
 		 * @return {@code this} builder
 		 */
@@ -181,9 +180,9 @@ public class ServerSentEvent<T> {
          * @return the built event
          */
         ServerSentEvent<T> build();
-
     }
 
+
     private static class BuilderImpl<T> implements Builder<T> {
 
 		@Nullable

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Decoder.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.http.codec.json;
 
 import java.io.IOException;
@@ -54,7 +55,6 @@ import org.springframework.util.MimeType;
  */
 public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport implements HttpMessageDecoder<Object> {
 
-
 	/**
 	 * Constructor with a Jackson {@link ObjectMapper} to use.
 	 */
@@ -144,4 +144,5 @@ public abstract class AbstractJackson2Decoder extends Jackson2CodecSupport imple
 	protected <A extends Annotation> A getAnnotation(MethodParameter parameter, Class<A> annotType) {
 		return parameter.getParameterAnnotation(annotType);
 	}
+
 }

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Encoder.java

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.http.codec.json;
 
 import java.io.IOException;
@@ -57,6 +58,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 
 	protected final List<MediaType> streamingMediaTypes = new ArrayList<>(1);
 
+
 	/**
 	 * Constructor with a Jackson {@link ObjectMapper} to use.
 	 */
@@ -64,6 +66,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 		super(mapper, mimeTypes);
 	}
 
+
 	/**
 	 * Configure "streaming" media types for which flushing should be performed
 	 * automatically vs at the end of the stream.
@@ -76,6 +79,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 		this.streamingMediaTypes.addAll(mediaTypes);
 	}
 
+
 	@Override
 	public boolean canEncode(ResolvableType elementType, @Nullable MimeType mimeType) {
 		Class<?> clazz = elementType.resolve(Object.class);
@@ -143,6 +147,7 @@ public abstract class AbstractJackson2Encoder extends Jackson2CodecSupport imple
 	
 	protected ObjectWriter customizeWriter(ObjectWriter writer, @Nullable MimeType mimeType,
 			ResolvableType elementType, @Nullable Map<String, Object> hints) {
+
 		return writer;
 	}
 

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2CodecSupport.java

@@ -83,7 +83,7 @@ public abstract class Jackson2CodecSupport {
 	}
 
 	/**
-	 * Sub-classes should expose this as "decodable" or "encodable" mime types.
+	 * Subclasses should expose this as "decodable" or "encodable" mime types.
 	 */
 	protected List<MimeType> getMimeTypes() {
 		return this.mimeTypes;

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2JsonDecoder.java

@@ -19,6 +19,7 @@ package org.springframework.http.codec.json;
 import java.util.List;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+
 import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
 import org.springframework.util.MimeType;
 
@@ -40,8 +41,10 @@ public class Jackson2JsonDecoder extends AbstractJackson2Decoder {
 		super(mapper, mimeTypes);
 	}
 
+
 	@Override
 	public List<MimeType> getDecodableMimeTypes() {
 		return getMimeTypes();
 	}
+
 }

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2JsonEncoder.java

@@ -63,16 +63,20 @@ public class Jackson2JsonEncoder extends AbstractJackson2Encoder {
 		return printer;
 	}
 
+
 	@Override
 	protected ObjectWriter customizeWriter(ObjectWriter writer, @Nullable MimeType mimeType,
 			ResolvableType elementType, @Nullable Map<String, Object> hints) {
 		
-		return (this.ssePrettyPrinter != null && MediaType.TEXT_EVENT_STREAM.isCompatibleWith(mimeType) &&
-				writer.getConfig().isEnabled(SerializationFeature.INDENT_OUTPUT) ? writer.with(this.ssePrettyPrinter) : writer);
+		return (this.ssePrettyPrinter != null &&
+				MediaType.TEXT_EVENT_STREAM.isCompatibleWith(mimeType) &&
+				writer.getConfig().isEnabled(SerializationFeature.INDENT_OUTPUT) ?
+				writer.with(this.ssePrettyPrinter) : writer);
 	}
 
 	@Override
 	public List<MimeType> getEncodableMimeTypes() {
 		return getMimeTypes();
 	}
+
 }

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2SmileDecoder.java

@@ -16,7 +16,7 @@
 
 package org.springframework.http.codec.json;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -51,6 +51,7 @@ public class Jackson2SmileDecoder extends AbstractJackson2Decoder {
 
 	@Override
 	public List<MimeType> getDecodableMimeTypes() {
-		return Arrays.asList(SMILE_MIME_TYPE);
+		return Collections.singletonList(SMILE_MIME_TYPE);
 	}
+
 }

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2SmileEncoder.java

@@ -16,7 +16,7 @@
 
 package org.springframework.http.codec.json;
 
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -49,8 +49,10 @@ public class Jackson2SmileEncoder extends AbstractJackson2Encoder {
 		this.streamingMediaTypes.add(new MediaType("application", "stream+x-jackson-smile"));
 	}
 
+
 	@Override
 	public List<MimeType> getEncodableMimeTypes() {
-		return Arrays.asList(SMILE_MIME_TYPE);
+		return Collections.singletonList(SMILE_MIME_TYPE);
 	}
+
 }

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.http.codec;
+package org.springframework.http.codec.support;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -32,6 +32,12 @@ import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
+import org.springframework.http.codec.CodecConfigurer;
+import org.springframework.http.codec.DecoderHttpMessageReader;
+import org.springframework.http.codec.EncoderHttpMessageWriter;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.http.codec.json.Jackson2SmileDecoder;
@@ -50,7 +56,7 @@ import org.springframework.util.ClassUtils;
  */
 abstract class AbstractCodecConfigurer implements CodecConfigurer {
 
-	protected static final boolean jackson2Present =
+	static final boolean jackson2Present =
 			ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper",
 					AbstractCodecConfigurer.class.getClassLoader()) &&
 					ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator",
@@ -60,8 +66,8 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 			ClassUtils.isPresent("com.fasterxml.jackson.dataformat.smile.SmileFactory",
 					AbstractCodecConfigurer.class.getClassLoader());
 
-	protected static final boolean jaxb2Present = ClassUtils.isPresent("javax.xml.bind.Binder",
-			AbstractCodecConfigurer.class.getClassLoader());
+	private static final boolean jaxb2Present =
+			ClassUtils.isPresent("javax.xml.bind.Binder", AbstractCodecConfigurer.class.getClassLoader());
 
 
 	private final AbstractDefaultCodecs defaultCodecs;
@@ -69,7 +75,7 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 	private final DefaultCustomCodecs customCodecs = new DefaultCustomCodecs();
 
 
-	protected AbstractCodecConfigurer(AbstractDefaultCodecs defaultCodecs) {
+	AbstractCodecConfigurer(AbstractDefaultCodecs defaultCodecs) {
 		Assert.notNull(defaultCodecs, "'defaultCodecs' is required");
 		this.defaultCodecs = defaultCodecs;
 		this.defaultCodecs.setCustomCodecs(this.customCodecs);
@@ -83,7 +89,7 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 
 	@Override
 	public void registerDefaults(boolean shouldRegister) {
-		this.defaultCodecs.setRegisterDefaults(shouldRegister);
+		this.defaultCodecs.registerDefaults(shouldRegister);
 	}
 
 	@Override
@@ -120,60 +126,60 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 	}
 
 
-	abstract protected static class AbstractDefaultCodecs implements DefaultCodecs {
+	abstract static class AbstractDefaultCodecs implements DefaultCodecs {
 
 		private boolean registerDefaults = true;
 
 		@Nullable
-		private Jackson2JsonDecoder jackson2JsonDecoder;
+		private Decoder<?> jackson2JsonDecoder;
 
 		@Nullable
-		private Jackson2JsonEncoder jackson2JsonEncoder;
+		private Encoder<?> jackson2JsonEncoder;
 
 		@Nullable
 		private DefaultCustomCodecs customCodecs;
 
-		public void setRegisterDefaults(boolean registerDefaults) {
+		void registerDefaults(boolean registerDefaults) {
 			this.registerDefaults = registerDefaults;
 		}
 
-		public boolean shouldRegisterDefaults() {
+		boolean shouldRegisterDefaults() {
 			return this.registerDefaults;
 		}
 
 		/**
-		 * Access to custom codecs for sub-classes, e.g. for multipart writers.
+		 * Access to custom codecs for subclasses, e.g. for multipart writers.
 		 */
-		public void setCustomCodecs(@Nullable DefaultCustomCodecs customCodecs) {
+		void setCustomCodecs(@Nullable DefaultCustomCodecs customCodecs) {
 			this.customCodecs = customCodecs;
 		}
 
 		@Nullable
-		public DefaultCustomCodecs getCustomCodecs() {
+		DefaultCustomCodecs getCustomCodecs() {
 			return this.customCodecs;
 		}
 
 		@Override
-		public void jackson2JsonDecoder(Jackson2JsonDecoder decoder) {
+		public void jackson2JsonDecoder(Decoder<?> decoder) {
 			this.jackson2JsonDecoder = decoder;
 		}
 
-		protected Jackson2JsonDecoder jackson2JsonDecoder() {
+		Decoder<?> getJackson2JsonDecoder() {
 			return (this.jackson2JsonDecoder != null ? this.jackson2JsonDecoder : new Jackson2JsonDecoder());
 		}
 
 		@Override
-		public void jackson2JsonEncoder(Jackson2JsonEncoder encoder) {
+		public void jackson2JsonEncoder(Encoder<?> encoder) {
 			this.jackson2JsonEncoder = encoder;
 		}
 
-		protected Jackson2JsonEncoder jackson2JsonEncoder() {
+		Encoder<?> getJackson2JsonEncoder() {
 			return (this.jackson2JsonEncoder != null ? this.jackson2JsonEncoder : new Jackson2JsonEncoder());
 		}
 
 		// Readers...
 
-		public List<HttpMessageReader<?>> getTypedReaders() {
+		List<HttpMessageReader<?>> getTypedReaders() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
@@ -186,26 +192,26 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 			return result;
 		}
 
-		protected abstract boolean splitTextOnNewLine();
+		abstract boolean splitTextOnNewLine();
 
-		public List<HttpMessageReader<?>> getObjectReaders() {
+		List<HttpMessageReader<?>> getObjectReaders() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
 			List<HttpMessageReader<?>> result = new ArrayList<>();
-			if (jaxb2Present) {
-				result.add(new DecoderHttpMessageReader<>(new Jaxb2XmlDecoder()));
-			}
 			if (jackson2Present) {
-				result.add(new DecoderHttpMessageReader<>(jackson2JsonDecoder()));
+				result.add(new DecoderHttpMessageReader<>(getJackson2JsonDecoder()));
 			}
 			if (jackson2SmilePresent) {
 				result.add(new DecoderHttpMessageReader<>(new Jackson2SmileDecoder()));
 			}
+			if (jaxb2Present) {
+				result.add(new DecoderHttpMessageReader<>(new Jaxb2XmlDecoder()));
+			}
 			return result;
 		}
 
-		public List<HttpMessageReader<?>> getCatchAllReaders() {
+		List<HttpMessageReader<?>> getCatchAllReaders() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
@@ -216,7 +222,7 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 
 		// Writers...
 
-		public List<HttpMessageWriter<?>> getTypedWriters() {
+		List<HttpMessageWriter<?>> getTypedWriters() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
@@ -229,24 +235,24 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 			return result;
 		}
 
-		public List<HttpMessageWriter<?>> getObjectWriters() {
+		List<HttpMessageWriter<?>> getObjectWriters() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
 			List<HttpMessageWriter<?>> result = new ArrayList<>();
-			if (jaxb2Present) {
-				result.add(new EncoderHttpMessageWriter<>(new Jaxb2XmlEncoder()));
-			}
 			if (jackson2Present) {
-				result.add(new EncoderHttpMessageWriter<>(jackson2JsonEncoder()));
+				result.add(new EncoderHttpMessageWriter<>(getJackson2JsonEncoder()));
 			}
 			if (jackson2SmilePresent) {
 				result.add(new EncoderHttpMessageWriter<>(new Jackson2SmileEncoder()));
 			}
+			if (jaxb2Present) {
+				result.add(new EncoderHttpMessageWriter<>(new Jaxb2XmlEncoder()));
+			}
 			return result;
 		}
 
-		public List<HttpMessageWriter<?>> getCatchAllWriters() {
+		List<HttpMessageWriter<?>> getCatchAllWriters() {
 			if (!this.registerDefaults) {
 				return Collections.emptyList();
 			}
@@ -257,7 +263,7 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 	}
 
 
-	protected static class DefaultCustomCodecs implements CustomCodecs {
+	static class DefaultCustomCodecs implements CustomCodecs {
 
 		private final List<HttpMessageReader<?>> typedReaders = new ArrayList<>();
 
@@ -289,19 +295,19 @@ abstract class AbstractCodecConfigurer implements CodecConfigurer {
 			(canWriteObject ? this.objectWriters : this.typedWriters).add(writer);
 		}
 
-		public List<HttpMessageReader<?>> getTypedReaders() {
+		List<HttpMessageReader<?>> getTypedReaders() {
 			return this.typedReaders;
 		}
 
-		public List<HttpMessageWriter<?>> getTypedWriters() {
+		List<HttpMessageWriter<?>> getTypedWriters() {
 			return this.typedWriters;
 		}
 
-		public List<HttpMessageReader<?>> getObjectReaders() {
+		List<HttpMessageReader<?>> getObjectReaders() {
 			return this.objectReaders;
 		}
 
-		public List<HttpMessageWriter<?>> getObjectWriters() {
+		List<HttpMessageWriter<?>> getObjectWriters() {
 			return this.objectWriters;
 		}
 	}

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.http.codec;
+package org.springframework.http.codec.support;
 
 import java.util.ArrayList;
 import java.util.Collections;
@@ -22,6 +22,12 @@ import java.util.List;
 
 import org.springframework.core.codec.Decoder;
 import org.springframework.core.codec.Encoder;
+import org.springframework.http.codec.ClientCodecConfigurer;
+import org.springframework.http.codec.EncoderHttpMessageWriter;
+import org.springframework.http.codec.FormHttpMessageWriter;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ServerSentEventHttpMessageReader;
 import org.springframework.http.codec.multipart.MultipartHttpMessageWriter;
 import org.springframework.lang.Nullable;
 
@@ -31,7 +37,7 @@ import org.springframework.lang.Nullable;
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-class DefaultClientCodecConfigurer extends AbstractCodecConfigurer implements ClientCodecConfigurer {
+public class DefaultClientCodecConfigurer extends AbstractCodecConfigurer implements ClientCodecConfigurer {
 
 	public DefaultClientCodecConfigurer() {
 		super(new ClientDefaultCodecsImpl());
@@ -65,12 +71,12 @@ class DefaultClientCodecConfigurer extends AbstractCodecConfigurer implements Cl
 		}
 
 		@Override
-		protected boolean splitTextOnNewLine() {
+		boolean splitTextOnNewLine() {
 			return false;
 		}
 
 		@Override
-		public List<HttpMessageReader<?>> getObjectReaders() {
+		List<HttpMessageReader<?>> getObjectReaders() {
 			if (!shouldRegisterDefaults()) {
 				return Collections.emptyList();
 			}
@@ -84,12 +90,12 @@ class DefaultClientCodecConfigurer extends AbstractCodecConfigurer implements Cl
 			if (this.sseDecoder != null) {
 				return this.sseDecoder;
 			}
-			return (jackson2Present ? jackson2JsonDecoder() : null);
+			return (jackson2Present ? getJackson2JsonDecoder() : null);
 		}
 
 		@Override
-		public List<HttpMessageWriter<?>> getTypedWriters() {
-			if (!this.shouldRegisterDefaults()) {
+		List<HttpMessageWriter<?>> getTypedWriters() {
+			if (!shouldRegisterDefaults()) {
 				return Collections.emptyList();
 			}
 			List<HttpMessageWriter<?>> result = super.getTypedWriters();
@@ -137,7 +143,7 @@ class DefaultClientCodecConfigurer extends AbstractCodecConfigurer implements Cl
 			return this;
 		}
 
-		public List<HttpMessageWriter<?>> getWriters() {
+		List<HttpMessageWriter<?>> getWriters() {
 			return this.writers;
 		}
 	}

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

@@ -14,12 +14,17 @@
  * limitations under the License.
  */
 
-package org.springframework.http.codec;
+package org.springframework.http.codec.support;
 
 import java.util.Collections;
 import java.util.List;
 
 import org.springframework.core.codec.Encoder;
+import org.springframework.http.codec.FormHttpMessageReader;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ServerCodecConfigurer;
+import org.springframework.http.codec.ServerSentEventHttpMessageWriter;
 import org.springframework.http.codec.multipart.MultipartHttpMessageReader;
 import org.springframework.http.codec.multipart.SynchronossPartHttpMessageReader;
 import org.springframework.lang.Nullable;
@@ -31,11 +36,11 @@ import org.springframework.util.ClassUtils;
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-class DefaultServerCodecConfigurer extends AbstractCodecConfigurer implements ServerCodecConfigurer {
+public class DefaultServerCodecConfigurer extends AbstractCodecConfigurer implements ServerCodecConfigurer {
 
-	static final boolean synchronossMultipartPresent = ClassUtils.isPresent(
-			"org.synchronoss.cloud.nio.multipart.NioMultipartParser",
-			DefaultServerCodecConfigurer.class.getClassLoader());
+	static final boolean synchronossMultipartPresent =
+			ClassUtils.isPresent("org.synchronoss.cloud.nio.multipart.NioMultipartParser",
+					DefaultServerCodecConfigurer.class.getClassLoader());
 
 
 	public DefaultServerCodecConfigurer() {
@@ -62,12 +67,12 @@ class DefaultServerCodecConfigurer extends AbstractCodecConfigurer implements Se
 		}
 
 		@Override
-		protected boolean splitTextOnNewLine() {
+		boolean splitTextOnNewLine() {
 			return true;
 		}
 
 		@Override
-		public List<HttpMessageReader<?>> getTypedReaders() {
+		List<HttpMessageReader<?>> getTypedReaders() {
 			if (!shouldRegisterDefaults()) {
 				return Collections.emptyList();
 			}
@@ -82,7 +87,7 @@ class DefaultServerCodecConfigurer extends AbstractCodecConfigurer implements Se
 		}
 
 		@Override
-		public List<HttpMessageWriter<?>> getObjectWriters() {
+		List<HttpMessageWriter<?>> getObjectWriters() {
 			if (!shouldRegisterDefaults()) {
 				return Collections.emptyList();
 			}
@@ -96,7 +101,7 @@ class DefaultServerCodecConfigurer extends AbstractCodecConfigurer implements Se
 			if (this.sseEncoder != null) {
 				return this.sseEncoder;
 			}
-			return jackson2Present ? jackson2JsonEncoder() : null;
+			return jackson2Present ? getJackson2JsonEncoder() : null;
 		}
 	}
 

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

@@ -0,0 +1,11 @@
+/**
+ * Provides implementations of {@link org.springframework.http.codec.ClientCodecConfigurer}
+ * and {@link org.springframework.http.codec.ServerCodecConfigurer} based on the converter
+ * implementations from {@code org.springframework.http.codec.json} and co.
+ */
+@NonNullApi
+@NonNullFields
+package org.springframework.http.codec.support;
+
+import org.springframework.lang.NonNullApi;
+import org.springframework.lang.NonNullFields;

spring-web/src/main/resources/org/springframework/http/codec/CodecConfigurer.properties

@@ -0,0 +1,5 @@
+# Default CodecConfigurer implementation classes for static Client/ServerCodecConfigurer.create() calls.
+# Not meant to be customized by application developers; simply instantiate custom impl classes instead.
+
+org.springframework.http.codec.ClientCodecConfigurer=org.springframework.http.codec.support.DefaultClientCodecConfigurer
+org.springframework.http.codec.ServerCodecConfigurer=org.springframework.http.codec.support.DefaultServerCodecConfigurer

spring-web/src/test/java/org/springframework/http/codec/support/ClientCodecConfigurerTests.java

@@ -13,7 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.http.codec;
+
+package org.springframework.http.codec.support;
 
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
@@ -38,6 +39,14 @@ import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
+import org.springframework.http.codec.ClientCodecConfigurer;
+import org.springframework.http.codec.DecoderHttpMessageReader;
+import org.springframework.http.codec.EncoderHttpMessageWriter;
+import org.springframework.http.codec.FormHttpMessageWriter;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageWriter;
+import org.springframework.http.codec.ServerSentEventHttpMessageReader;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.http.codec.json.Jackson2SmileDecoder;
@@ -48,10 +57,11 @@ import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
 import org.springframework.util.MimeTypeUtils;
 
 import static org.junit.Assert.*;
-import static org.springframework.core.ResolvableType.forClass;
+import static org.springframework.core.ResolvableType.*;
 
 /**
  * Unit tests for {@link ClientCodecConfigurer}.
+ *
  * @author Rossen Stoyanchev
  */
 public class ClientCodecConfigurerTests {
@@ -62,7 +72,7 @@ public class ClientCodecConfigurerTests {
 
 
 	@Test
-	public void defaultReaders() throws Exception {
+	public void defaultReaders() {
 		List<HttpMessageReader<?>> readers = this.configurer.getReaders();
 		assertEquals(10, readers.size());
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
@@ -70,15 +80,15 @@ public class ClientCodecConfigurerTests {
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
 		assertStringDecoder(getNextDecoder(readers), true);
-		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2JsonDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2SmileDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertSseReader(readers);
 		assertStringDecoder(getNextDecoder(readers), false);
 	}
 
 	@Test
-	public void defaultWriters() throws Exception {
+	public void defaultWriters() {
 		List<HttpMessageWriter<?>> writers = this.configurer.getWriters();
 		assertEquals(11, writers.size());
 		assertEquals(ByteArrayEncoder.class, getNextEncoder(writers).getClass());
@@ -88,15 +98,14 @@ public class ClientCodecConfigurerTests {
 		assertStringEncoder(getNextEncoder(writers), true);
 		assertEquals(FormHttpMessageWriter.class, writers.get(this.index.getAndIncrement()).getClass());
 		assertEquals(MultipartHttpMessageWriter.class, writers.get(this.index.getAndIncrement()).getClass());
-		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2JsonEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2SmileEncoder.class, getNextEncoder(writers).getClass());
+		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertStringEncoder(getNextEncoder(writers), false);
 	}
 
 	@Test
-	public void jackson2EncoderOverride() throws Exception {
-
+	public void jackson2EncoderOverride() {
 		Jackson2JsonDecoder decoder = new Jackson2JsonDecoder();
 		this.configurer.defaultCodecs().jackson2JsonDecoder(decoder);
 

spring-web/src/test/java/org/springframework/http/codec/support/CodecConfigurerTests.java

@@ -13,7 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.http.codec;
+
+package org.springframework.http.codec.support;
 
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -33,6 +34,12 @@ import org.springframework.core.codec.Encoder;
 import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.http.MediaType;
+import org.springframework.http.codec.CodecConfigurer;
+import org.springframework.http.codec.DecoderHttpMessageReader;
+import org.springframework.http.codec.EncoderHttpMessageWriter;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.http.codec.json.Jackson2SmileDecoder;
@@ -41,12 +48,9 @@ import org.springframework.http.codec.xml.Jaxb2XmlDecoder;
 import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
 import org.springframework.util.MimeTypeUtils;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-import static org.springframework.core.ResolvableType.forClass;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+import static org.springframework.core.ResolvableType.*;
 
 /**
  * Unit tests for {@link AbstractCodecConfigurer.AbstractDefaultCodecs}.
@@ -60,7 +64,7 @@ public class CodecConfigurerTests {
 
 
 	@Test
-	public void defaultReaders() throws Exception {
+	public void defaultReaders() {
 		List<HttpMessageReader<?>> readers = this.configurer.getReaders();
 		assertEquals(9, readers.size());
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
@@ -68,14 +72,14 @@ public class CodecConfigurerTests {
 		assertEquals(DataBufferDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(ResourceDecoder.class, getNextDecoder(readers).getClass());
 		assertStringDecoder(getNextDecoder(readers), true);
-		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2JsonDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2SmileDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertStringDecoder(getNextDecoder(readers), false);
 	}
 
 	@Test
-	public void defaultWriters() throws Exception {
+	public void defaultWriters() {
 		List<HttpMessageWriter<?>> writers = this.configurer.getWriters();
 		assertEquals(9, writers.size());
 		assertEquals(ByteArrayEncoder.class, getNextEncoder(writers).getClass());
@@ -83,15 +87,14 @@ public class CodecConfigurerTests {
 		assertEquals(DataBufferEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(ResourceHttpMessageWriter.class, writers.get(index.getAndIncrement()).getClass());
 		assertStringEncoder(getNextEncoder(writers), true);
-		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2JsonEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2SmileEncoder.class, getNextEncoder(writers).getClass());
+		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertStringEncoder(getNextEncoder(writers), false);
 	}
 
 	@Test
-	public void defaultAndCustomReaders() throws Exception {
-
+	public void defaultAndCustomReaders() {
 		Decoder<?> customDecoder1 = mock(Decoder.class);
 		Decoder<?> customDecoder2 = mock(Decoder.class);
 
@@ -120,17 +123,16 @@ public class CodecConfigurerTests {
 		assertEquals(StringDecoder.class, getNextDecoder(readers).getClass());
 		assertSame(customDecoder1, getNextDecoder(readers));
 		assertSame(customReader1, readers.get(this.index.getAndIncrement()));
-		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2JsonDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2SmileDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertSame(customDecoder2, getNextDecoder(readers));
 		assertSame(customReader2, readers.get(this.index.getAndIncrement()));
 		assertEquals(StringDecoder.class, getNextDecoder(readers).getClass());
 	}
 
 	@Test
-	public void defaultAndCustomWriters() throws Exception {
-
+	public void defaultAndCustomWriters() {
 		Encoder<?> customEncoder1 = mock(Encoder.class);
 		Encoder<?> customEncoder2 = mock(Encoder.class);
 
@@ -159,17 +161,16 @@ public class CodecConfigurerTests {
 		assertEquals(CharSequenceEncoder.class, getNextEncoder(writers).getClass());
 		assertSame(customEncoder1, getNextEncoder(writers));
 		assertSame(customWriter1, writers.get(this.index.getAndIncrement()));
-		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2JsonEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2SmileEncoder.class, getNextEncoder(writers).getClass());
+		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertSame(customEncoder2, getNextEncoder(writers));
 		assertSame(customWriter2, writers.get(this.index.getAndIncrement()));
 		assertEquals(CharSequenceEncoder.class, getNextEncoder(writers).getClass());
 	}
 
 	@Test
-	public void defaultsOffCustomReaders() throws Exception {
-
+	public void defaultsOffCustomReaders() {
 		Decoder<?> customDecoder1 = mock(Decoder.class);
 		Decoder<?> customDecoder2 = mock(Decoder.class);
 
@@ -200,8 +201,7 @@ public class CodecConfigurerTests {
 	}
 
 	@Test
-	public void defaultsOffWithCustomWriters() throws Exception {
-
+	public void defaultsOffWithCustomWriters() {
 		Encoder<?> customEncoder1 = mock(Encoder.class);
 		Encoder<?> customEncoder2 = mock(Encoder.class);
 
@@ -232,8 +232,7 @@ public class CodecConfigurerTests {
 	}
 
 	@Test
-	public void jackson2DecoderOverride() throws Exception {
-
+	public void jackson2DecoderOverride() {
 		Jackson2JsonDecoder decoder = new Jackson2JsonDecoder();
 		this.configurer.defaultCodecs().jackson2JsonDecoder(decoder);
 
@@ -246,8 +245,7 @@ public class CodecConfigurerTests {
 	}
 
 	@Test
-	public void jackson2EncoderOverride() throws Exception {
-
+	public void jackson2EncoderOverride() {
 		Jackson2JsonEncoder encoder = new Jackson2JsonEncoder();
 		this.configurer.defaultCodecs().jackson2JsonEncoder(encoder);
 
@@ -295,7 +293,7 @@ public class CodecConfigurerTests {
 		private static class TestDefaultCodecs extends AbstractDefaultCodecs {
 
 			@Override
-			protected boolean splitTextOnNewLine() {
+			boolean splitTextOnNewLine() {
 				return true;
 			}
 		}

spring-web/src/test/java/org/springframework/http/codec/support/ServerCodecConfigurerTests.java

@@ -13,7 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.springframework.http.codec;
+
+package org.springframework.http.codec.support;
 
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
@@ -39,6 +40,14 @@ import org.springframework.core.codec.ResourceDecoder;
 import org.springframework.core.codec.StringDecoder;
 import org.springframework.core.io.buffer.DefaultDataBufferFactory;
 import org.springframework.http.MediaType;
+import org.springframework.http.codec.DecoderHttpMessageReader;
+import org.springframework.http.codec.EncoderHttpMessageWriter;
+import org.springframework.http.codec.FormHttpMessageReader;
+import org.springframework.http.codec.HttpMessageReader;
+import org.springframework.http.codec.HttpMessageWriter;
+import org.springframework.http.codec.ResourceHttpMessageWriter;
+import org.springframework.http.codec.ServerCodecConfigurer;
+import org.springframework.http.codec.ServerSentEventHttpMessageWriter;
 import org.springframework.http.codec.json.Jackson2JsonDecoder;
 import org.springframework.http.codec.json.Jackson2JsonEncoder;
 import org.springframework.http.codec.json.Jackson2SmileDecoder;
@@ -50,10 +59,11 @@ import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
 import org.springframework.util.MimeTypeUtils;
 
 import static org.junit.Assert.*;
-import static org.springframework.core.ResolvableType.forClass;
+import static org.springframework.core.ResolvableType.*;
 
 /**
  * Unit tests for {@link ServerCodecConfigurer}.
+ *
  * @author Rossen Stoyanchev
  */
 public class ServerCodecConfigurerTests {
@@ -64,7 +74,7 @@ public class ServerCodecConfigurerTests {
 
 
 	@Test
-	public void defaultReaders() throws Exception {
+	public void defaultReaders() {
 		List<HttpMessageReader<?>> readers = this.configurer.getReaders();
 		assertEquals(12, readers.size());
 		assertEquals(ByteArrayDecoder.class, getNextDecoder(readers).getClass());
@@ -75,14 +85,14 @@ public class ServerCodecConfigurerTests {
 		assertEquals(FormHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertEquals(SynchronossPartHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
 		assertEquals(MultipartHttpMessageReader.class, readers.get(this.index.getAndIncrement()).getClass());
-		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2JsonDecoder.class, getNextDecoder(readers).getClass());
 		assertEquals(Jackson2SmileDecoder.class, getNextDecoder(readers).getClass());
+		assertEquals(Jaxb2XmlDecoder.class, getNextDecoder(readers).getClass());
 		assertStringDecoder(getNextDecoder(readers), false);
 	}
 
 	@Test
-	public void defaultWriters() throws Exception {
+	public void defaultWriters() {
 		List<HttpMessageWriter<?>> writers = this.configurer.getWriters();
 		assertEquals(10, writers.size());
 		assertEquals(ByteArrayEncoder.class, getNextEncoder(writers).getClass());
@@ -90,16 +100,15 @@ public class ServerCodecConfigurerTests {
 		assertEquals(DataBufferEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(ResourceHttpMessageWriter.class, writers.get(index.getAndIncrement()).getClass());
 		assertStringEncoder(getNextEncoder(writers), true);
-		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2JsonEncoder.class, getNextEncoder(writers).getClass());
 		assertEquals(Jackson2SmileEncoder.class, getNextEncoder(writers).getClass());
+		assertEquals(Jaxb2XmlEncoder.class, getNextEncoder(writers).getClass());
 		assertSseWriter(writers);
 		assertStringEncoder(getNextEncoder(writers), false);
 	}
 
 	@Test
-	public void jackson2EncoderOverride() throws Exception {
-
+	public void jackson2EncoderOverride() {
 		Jackson2JsonEncoder encoder = new Jackson2JsonEncoder();
 		this.configurer.defaultCodecs().jackson2JsonEncoder(encoder);