001/*
002 * Copyright 2002-2019 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.core.codec;
018
019import java.nio.ByteBuffer;
020import java.util.Map;
021
022import org.springframework.core.ResolvableType;
023import org.springframework.core.io.buffer.DataBuffer;
024import org.springframework.core.io.buffer.DataBufferUtils;
025import org.springframework.lang.Nullable;
026import org.springframework.util.MimeType;
027import org.springframework.util.MimeTypeUtils;
028
029/**
030 * Decoder for {@link ByteBuffer ByteBuffers}.
031 *
032 * @author Sebastien Deleuze
033 * @author Arjen Poutsma
034 * @author Rossen Stoyanchev
035 * @since 5.0
036 */
037public class ByteBufferDecoder extends AbstractDataBufferDecoder<ByteBuffer> {
038
039        public ByteBufferDecoder() {
040                super(MimeTypeUtils.ALL);
041        }
042
043
044        @Override
045        public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
046                return (ByteBuffer.class.isAssignableFrom(elementType.toClass()) &&
047                                super.canDecode(elementType, mimeType));
048        }
049
050        @Override
051        public ByteBuffer decode(DataBuffer dataBuffer, ResolvableType elementType,
052                        @Nullable MimeType mimeType, @Nullable Map<String, Object> hints) {
053
054                int byteCount = dataBuffer.readableByteCount();
055                ByteBuffer copy = ByteBuffer.allocate(byteCount);
056                copy.put(dataBuffer.asByteBuffer());
057                copy.flip();
058                DataBufferUtils.release(dataBuffer);
059                if (logger.isDebugEnabled()) {
060                        logger.debug(Hints.getLogPrefix(hints) + "Read " + byteCount + " bytes");
061                }
062                return copy;
063        }
064
065}