org.springframework.core.codec.CharBufferDecoder Maven / Gradle / Ivy
/*
* Copyright 2002-2023 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
*
* https://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.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.util.List;
import org.springframework.core.ResolvableType;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.lang.Nullable;
import org.springframework.util.MimeType;
import org.springframework.util.MimeTypeUtils;
/**
* Decode from a data buffer stream to a {@code CharBuffer} stream, either splitting
* or aggregating incoming data chunks to realign along newlines delimiters
* and produce a stream of char buffers. This is useful for streaming but is also
* necessary to ensure that multi-byte characters can be decoded correctly,
* avoiding split-character issues. The default delimiters used by default are
* {@code \n} and {@code \r\n} but that can be customized.
*
* @author Markus Heiden
* @author Arjen Poutsma
* @since 6.1
* @see CharSequenceEncoder
*/
public final class CharBufferDecoder extends AbstractCharSequenceDecoder {
public CharBufferDecoder(List delimiters, boolean stripDelimiter, MimeType... mimeTypes) {
super(delimiters, stripDelimiter, mimeTypes);
}
@Override
public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
return (elementType.resolve() == CharBuffer.class) && super.canDecode(elementType, mimeType);
}
@Override
protected CharBuffer decodeInternal(DataBuffer dataBuffer, Charset charset) {
ByteBuffer byteBuffer = ByteBuffer.allocate(dataBuffer.readableByteCount());
dataBuffer.toByteBuffer(byteBuffer);
return charset.decode(byteBuffer);
}
/**
* Create a {@code CharBufferDecoder} for {@code "text/plain"}.
*/
public static CharBufferDecoder textPlainOnly() {
return textPlainOnly(DEFAULT_DELIMITERS, true);
}
/**
* Create a {@code CharBufferDecoder} for {@code "text/plain"}.
* @param delimiters delimiter strings to use to split the input stream
* @param stripDelimiter whether to remove delimiters from the resulting input strings
*/
public static CharBufferDecoder textPlainOnly(List delimiters, boolean stripDelimiter) {
var textPlain = new MimeType("text", "plain", DEFAULT_CHARSET);
return new CharBufferDecoder(delimiters, stripDelimiter, textPlain);
}
/**
* Create a {@code CharBufferDecoder} that supports all MIME types.
*/
public static CharBufferDecoder allMimeTypes() {
return allMimeTypes(DEFAULT_DELIMITERS, true);
}
/**
* Create a {@code CharBufferDecoder} that supports all MIME types.
* @param delimiters delimiter strings to use to split the input stream
* @param stripDelimiter whether to remove delimiters from the resulting input strings
*/
public static CharBufferDecoder allMimeTypes(List delimiters, boolean stripDelimiter) {
var textPlain = new MimeType("text", "plain", DEFAULT_CHARSET);
return new CharBufferDecoder(delimiters, stripDelimiter, textPlain, MimeTypeUtils.ALL);
}
}