Add byte[] encoder and decoder

This commit adds a ByteArrayDecoder and ByteArrayEncoder.

spring-core/src/main/java/org/springframework/core/codec/ByteArrayDecoder.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2002-2016 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.core.codec;
+
+import java.util.Map;
+
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+
+import org.springframework.core.ResolvableType;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferUtils;
+import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
+
+/**
+ * Decoder for {@code byte} arrays.
+ *
+ * @author Arjen Poutsma
+ * @since 5.0
+ */
+public class ByteArrayDecoder extends AbstractDecoder<byte[]> {
+
+	public ByteArrayDecoder() {
+		super(MimeTypeUtils.ALL);
+	}
+
+
+	@Override
+	public boolean canDecode(ResolvableType elementType, MimeType mimeType) {
+		Class<?> clazz = elementType.getRawClass();
+		return (super.canDecode(elementType, mimeType) && byte[].class == clazz);
+	}
+
+	@Override
+	public Flux<byte[]> decode(Publisher<DataBuffer> inputStream, ResolvableType elementType,
+			MimeType mimeType, Map<String, Object> hints) {
+
+		return Flux.from(inputStream).map((dataBuffer) -> {
+			byte[] result = new byte[dataBuffer.readableByteCount()];
+			dataBuffer.read(result);
+			DataBufferUtils.release(dataBuffer);
+			return result ;
+		});
+	}
+
+
+}

spring-core/src/main/java/org/springframework/core/codec/ByteArrayEncoder.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2002-2016 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.core.codec;
+
+import java.util.Map;
+
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+
+import org.springframework.core.ResolvableType;
+import org.springframework.core.io.buffer.DataBuffer;
+import org.springframework.core.io.buffer.DataBufferFactory;
+import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
+
+/**
+ * Encoder for {@code byte} arrays.
+ *
+ * @author Arjen Poutsma
+ * @since 5.0
+ */
+public class ByteArrayEncoder extends AbstractEncoder<byte[]> {
+
+	public ByteArrayEncoder() {
+		super(MimeTypeUtils.ALL);
+	}
+
+
+	@Override
+	public boolean canEncode(ResolvableType elementType, MimeType mimeType) {
+		Class<?> clazz = elementType.getRawClass();
+		return (super.canEncode(elementType, mimeType) && byte[].class.isAssignableFrom(clazz));
+	}
+
+	@Override
+	public Flux<DataBuffer> encode(Publisher<? extends byte[]> inputStream,
+			DataBufferFactory bufferFactory, ResolvableType elementType, MimeType mimeType,
+			Map<String, Object> hints) {
+
+		return Flux.from(inputStream).map(bufferFactory::wrap);
+	}
+
+}

spring-core/src/main/java/org/springframework/core/io/buffer/DataBufferFactory.java

@@ -52,4 +52,11 @@ public interface DataBufferFactory {
 	 */
 	DataBuffer wrap(ByteBuffer byteBuffer);
 
+	/**
+	 * Wrap the given {@code byte} array in a {@code DataBuffer}.
+	 * @param bytes the byte array to wrap
+	 * @return the wrapped buffer
+	 */
+	DataBuffer wrap(byte[] bytes);
+
 }

spring-core/src/main/java/org/springframework/core/io/buffer/DefaultDataBufferFactory.java

@@ -94,6 +94,12 @@ public class DefaultDataBufferFactory implements DataBufferFactory {
 		return new DefaultDataBuffer(sliced, 0, byteBuffer.remaining(), this);
 	}
 
+	@Override
+	public DataBuffer wrap(byte[] bytes) {
+		ByteBuffer wrapper = ByteBuffer.wrap(bytes);
+		return new DefaultDataBuffer(wrapper, 0, bytes.length, this);
+	}
+
 	@Override
 	public String toString() {
 		return "DefaultDataBufferFactory (preferDirect=" + this.preferDirect + ")";

spring-core/src/main/java/org/springframework/core/io/buffer/NettyDataBufferFactory.java

@@ -68,6 +68,12 @@ public class NettyDataBufferFactory implements DataBufferFactory {
 		return new NettyDataBuffer(byteBuf, this);
 	}
 
+	@Override
+	public DataBuffer wrap(byte[] bytes) {
+		ByteBuf byteBuf = Unpooled.wrappedBuffer(bytes);
+		return new NettyDataBuffer(byteBuf, this);
+	}
+
 	/**
 	 * Wrap the given Netty {@link ByteBuf} in a {@code NettyDataBuffer}.
 	 * @param byteBuf the Netty byte buffer to wrap