/*
* Copyright 2002-2014 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.converter.feed;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.nio.charset.Charset;
import com.rometools.rome.feed.WireFeed;
import com.rometools.rome.io.FeedException;
import com.rometools.rome.io.WireFeedInput;
import com.rometools.rome.io.WireFeedOutput;
import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;
import org.springframework.util.StringUtils;
/**
* Abstract base class for Atom and RSS Feed message converters, using the
* <a href="https://github.com/rometools/rome">ROME tools</a> project.
*
* <p>><b>NOTE: As of Spring 4.1, this is based on the {@code com.rometools}
* variant of ROME, version 1.5. Please upgrade your build dependency.</b>
*
* @author Arjen Poutsma
* @since 3.0.2
* @see AtomFeedHttpMessageConverter
* @see RssChannelHttpMessageConverter
*/
public abstract class AbstractWireFeedHttpMessageConverter<T extends WireFeed> extends AbstractHttpMessageConverter<T> {
public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
protected AbstractWireFeedHttpMessageConverter(MediaType supportedMediaType) {
super(supportedMediaType);
}
@Override
@SuppressWarnings("unchecked")
protected T readInternal(Class<? extends T> clazz, HttpInputMessage inputMessage)
throws IOException, HttpMessageNotReadableException {
WireFeedInput feedInput = new WireFeedInput();
MediaType contentType = inputMessage.getHeaders().getContentType();
Charset charset =
(contentType != null && contentType.getCharSet() != null? contentType.getCharSet() : DEFAULT_CHARSET);
try {
Reader reader = new InputStreamReader(inputMessage.getBody(), charset);
return (T) feedInput.build(reader);
}
catch (FeedException ex) {
throw new HttpMessageNotReadableException("Could not read WireFeed: " + ex.getMessage(), ex);
}
}
@Override
protected void writeInternal(T wireFeed, HttpOutputMessage outputMessage)
throws IOException, HttpMessageNotWritableException {
String wireFeedEncoding = wireFeed.getEncoding();
if (!StringUtils.hasLength(wireFeedEncoding)) {
wireFeedEncoding = DEFAULT_CHARSET.name();
}
MediaType contentType = outputMessage.getHeaders().getContentType();
if (contentType != null) {
Charset wireFeedCharset = Charset.forName(wireFeedEncoding);
contentType = new MediaType(contentType.getType(), contentType.getSubtype(), wireFeedCharset);
outputMessage.getHeaders().setContentType(contentType);
}
WireFeedOutput feedOutput = new WireFeedOutput();
try {
Writer writer = new OutputStreamWriter(outputMessage.getBody(), wireFeedEncoding);
feedOutput.output(wireFeed, writer);
}
catch (FeedException ex) {
throw new HttpMessageNotWritableException("Could not write WireFeed: " + ex.getMessage(), ex);
}
}
}