/*
* 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.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.function.Supplier;
import org.springframework.core.ResolvableType;
import org.springframework.core.codec.ByteArrayDecoder;
import org.springframework.core.codec.ByteArrayEncoder;
import org.springframework.core.codec.ByteBufferDecoder;
import org.springframework.core.codec.ByteBufferEncoder;
import org.springframework.core.codec.CharSequenceEncoder;
import org.springframework.core.codec.DataBufferDecoder;
import org.springframework.core.codec.DataBufferEncoder;
import org.springframework.core.codec.Decoder;
import org.springframework.core.codec.Encoder;
import org.springframework.core.codec.ResourceDecoder;
import org.springframework.http.codec.json.Jackson2JsonDecoder;
import org.springframework.http.codec.json.Jackson2JsonEncoder;
import org.springframework.http.codec.xml.Jaxb2XmlDecoder;
import org.springframework.http.codec.xml.Jaxb2XmlEncoder;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* Default implementation of {@link CodecConfigurer}.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
class DefaultCodecConfigurer implements CodecConfigurer {
static final boolean jackson2Present =
ClassUtils.isPresent("com.fasterxml.jackson.databind.ObjectMapper",
org.springframework.http.codec.DefaultCodecConfigurer.class.getClassLoader()) &&
ClassUtils.isPresent("com.fasterxml.jackson.core.JsonGenerator",
org.springframework.http.codec.DefaultCodecConfigurer.class
.getClassLoader());
static final boolean jaxb2Present =
ClassUtils.isPresent("javax.xml.bind.Binder",
org.springframework.http.codec.DefaultCodecConfigurer.class.getClassLoader());
private final AbstractDefaultCodecsConfigurer defaultCodecs;
private final CustomCodecConfigurer customCodecs = new CustomCodecConfigurer();
/**
* Protected constructor with the configurer for default readers and writers.
*/
DefaultCodecConfigurer(AbstractDefaultCodecsConfigurer defaultCodecConfigurer) {
Assert.notNull(defaultCodecConfigurer, "DefaultCodecConfigurer is required.");
this.defaultCodecs = defaultCodecConfigurer;
}
@Override
public DefaultCodecsConfigurer defaultCodecs() {
return this.defaultCodecs;
}
@Override
public void registerDefaults(boolean registerDefaults) {
this.defaultCodecs.setSuppressed(!registerDefaults);
}
@Override
public CustomCodecsConfigurer customCodecs() {
return this.customCodecs;
}
@Override
public List<HttpMessageReader<?>> getReaders() {
List<HttpMessageReader<?>> result = new ArrayList<>();
this.defaultCodecs.addTypedReadersTo(result);
this.customCodecs.addTypedReadersTo(result);
this.defaultCodecs.addObjectReadersTo(result);
this.customCodecs.addObjectReadersTo(result);
// String + "*/*"
this.defaultCodecs.addStringReaderTo(result);
return result;
}
/**
* Prepare a list of HTTP message writers.
*/
@Override
public List<HttpMessageWriter<?>> getWriters() {
List<HttpMessageWriter<?>> result = new ArrayList<>();
this.defaultCodecs.addTypedWritersTo(result);
this.customCodecs.addTypedWritersTo(result);
this.defaultCodecs.addObjectWritersTo(result);
this.customCodecs.addObjectWritersTo(result);
// String + "*/*"
this.defaultCodecs.addStringWriterTo(result);
return result;
}
/**
* Default implementation for {@link CodecConfigurer.DefaultCodecsConfigurer}.
*/
abstract static class AbstractDefaultCodecsConfigurer
implements CodecConfigurer.DefaultCodecsConfigurer {
private boolean suppressed = false;
private final Map<Class<?>, HttpMessageReader<?>> readers = new HashMap<>();
private final Map<Class<?>, HttpMessageWriter<?>> writers = new HashMap<>();
@Override
public void jackson2Decoder(Jackson2JsonDecoder decoder) {
this.readers.put(Jackson2JsonDecoder.class, new DecoderHttpMessageReader<>(decoder));
}
@Override
public void jackson2Encoder(Jackson2JsonEncoder encoder) {
this.writers.put(Jackson2JsonEncoder.class, new EncoderHttpMessageWriter<>(encoder));
}
public void addTypedReadersTo(List<HttpMessageReader<?>> result) {
addReaderTo(result, ByteArrayDecoder.class, ByteArrayDecoder::new);
addReaderTo(result, ByteBufferDecoder.class, ByteBufferDecoder::new);
addReaderTo(result, DataBufferDecoder.class, DataBufferDecoder::new);
addReaderTo(result, ResourceDecoder.class, ResourceDecoder::new);
addStringReaderTextOnlyTo(result);
}
protected void addTypedWritersTo(List<HttpMessageWriter<?>> result) {
addWriterTo(result, ByteArrayEncoder.class, ByteArrayEncoder::new);
addWriterTo(result, ByteBufferEncoder.class, ByteBufferEncoder::new);
addWriterTo(result, DataBufferEncoder.class, DataBufferEncoder::new);
addWriterTo(result, ResourceHttpMessageWriter::new);
addStringWriterTextPlainOnlyTo(result);
}
protected void addObjectReadersTo(List<HttpMessageReader<?>> result) {
if (jaxb2Present) {
addReaderTo(result, Jaxb2XmlDecoder.class, Jaxb2XmlDecoder::new);
}
if (jackson2Present) {
addReaderTo(result, Jackson2JsonDecoder.class, Jackson2JsonDecoder::new);
}
}
protected void addObjectWritersTo(List<HttpMessageWriter<?>> result) {
if (jaxb2Present) {
addWriterTo(result, Jaxb2XmlEncoder.class, Jaxb2XmlEncoder::new);
}
if (jackson2Present) {
addWriterTo(result, Jackson2JsonEncoder.class, Jackson2JsonEncoder::new);
}
}
// Accessors for internal use...
protected Map<Class<?>, HttpMessageReader<?>> getReaders() {
return this.readers;
}
protected Map<Class<?>, HttpMessageWriter<?>> getWriters() {
return this.writers;
}
private void setSuppressed(boolean suppressed) {
this.suppressed = suppressed;
}
// Protected methods for building a list of default readers or writers...
protected <T, D extends Decoder<T>> void addReaderTo(List<HttpMessageReader<?>> result,
Class<D> key, Supplier<D> fallback) {
addReaderTo(result, () -> findDecoderReader(key, fallback));
}
protected void addReaderTo(List<HttpMessageReader<?>> result,
Supplier<HttpMessageReader<?>> reader) {
if (!this.suppressed) {
result.add(reader.get());
}
}
protected <T, D extends Decoder<T>> DecoderHttpMessageReader<?> findDecoderReader(
Class<D> decoderType, Supplier<D> fallback) {
DecoderHttpMessageReader<?> reader = (DecoderHttpMessageReader<?>) this.readers.get(decoderType);
return reader != null ? reader : new DecoderHttpMessageReader<>(fallback.get());
}
@SuppressWarnings("unchecked")
protected HttpMessageReader<?> findReader(Class<?> key, Supplier<HttpMessageReader<?>> fallback) {
return this.readers.containsKey(key) ? this.readers.get(key) : fallback.get();
}
protected <T, E extends Encoder<T>> void addWriterTo(List<HttpMessageWriter<?>> result,
Class<E> key, Supplier<E> fallback) {
addWriterTo(result, () -> findEncoderWriter(key, fallback));
}
protected void addWriterTo(List<HttpMessageWriter<?>> result,
Supplier<HttpMessageWriter<?>> writer) {
if (!this.suppressed) {
result.add(writer.get());
}
}
protected <T, E extends Encoder<T>> EncoderHttpMessageWriter<?> findEncoderWriter(
Class<E> encoderType, Supplier<E> fallback) {
EncoderHttpMessageWriter<?> writer = (EncoderHttpMessageWriter<?>) this.writers.get(encoderType);
return writer != null ? writer : new EncoderHttpMessageWriter<>(fallback.get());
}
@SuppressWarnings("unchecked")
protected HttpMessageWriter<?> findWriter(Class<?> key, Supplier<HttpMessageWriter<?>> fallback) {
return this.writers.containsKey(key) ? this.writers.get(key) : fallback.get();
}
protected abstract void addStringReaderTextOnlyTo(List<HttpMessageReader<?>> result);
protected abstract void addStringReaderTo(List<HttpMessageReader<?>> result);
protected void addStringWriterTextPlainOnlyTo(List<HttpMessageWriter<?>> result) {
addWriterTo(result, () -> new EncoderHttpMessageWriter<>(CharSequenceEncoder.textPlainOnly()));
}
protected void addStringWriterTo(List<HttpMessageWriter<?>> result) {
addWriterTo(result, () -> new EncoderHttpMessageWriter<>(CharSequenceEncoder.allMimeTypes()));
}
}
/**
* Default implementation of CustomCodecsConfigurer.
*/
private static class CustomCodecConfigurer implements CodecConfigurer.CustomCodecsConfigurer {
private final List<HttpMessageReader<?>> typedReaders = new ArrayList<>();
private final List<HttpMessageWriter<?>> typedWriters = new ArrayList<>();
private final List<HttpMessageReader<?>> objectReaders = new ArrayList<>();
private final List<HttpMessageWriter<?>> objectWriters = new ArrayList<>();
@Override
public void decoder(Decoder<?> decoder) {
reader(new DecoderHttpMessageReader<>(decoder));
}
@Override
public void encoder(Encoder<?> encoder) {
writer(new EncoderHttpMessageWriter<>(encoder));
}
@Override
public void reader(HttpMessageReader<?> reader) {
boolean canReadToObject = reader.canRead(ResolvableType.forClass(Object.class), null);
(canReadToObject ? this.objectReaders : this.typedReaders).add(reader);
}
@Override
public void writer(HttpMessageWriter<?> writer) {
boolean canWriteObject = writer.canWrite(ResolvableType.forClass(Object.class), null);
(canWriteObject ? this.objectWriters : this.typedWriters).add(writer);
}
// Internal methods for building a list of custom readers or writers...
protected void addTypedReadersTo(List<HttpMessageReader<?>> result) {
result.addAll(this.typedReaders);
}
protected void addObjectReadersTo(List<HttpMessageReader<?>> result) {
result.addAll(this.objectReaders);
}
protected void addTypedWritersTo(List<HttpMessageWriter<?>> result) {
result.addAll(this.typedWriters);
}
protected void addObjectWritersTo(List<HttpMessageWriter<?>> result) {
result.addAll(this.objectWriters);
}
}
}