/**
* This file is part of Graylog2.
*
* Graylog2 is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Graylog2 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Graylog2. If not, see <http://www.gnu.org/licenses/>.
*/
package org.graylog2.rest.resources.search.responses;
import au.com.bytecode.opencsv.CSVWriter;
import com.google.common.collect.ImmutableSortedSet;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import org.graylog2.indexer.results.ResultMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.nio.charset.StandardCharsets;
@Provider
@Produces("text/csv")
public class SearchResponseCsvWriter implements MessageBodyWriter<SearchResponse> {
public static final MediaType TEXT_CSV = new MediaType("text", "csv");
private static final Logger LOG = LoggerFactory.getLogger(SearchResponseCsvWriter.class);
@Override
public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return SearchResponse.class.equals(type) && TEXT_CSV.isCompatible(mediaType);
}
@Override
public long getSize(SearchResponse searchResponse, Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return -1;
}
@Override
public void writeTo(SearchResponse searchResponse, Class<?> type, Type genericType, Annotation[] annotations,
MediaType mediaType, MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
throws IOException, WebApplicationException {
final CSVWriter csvWriter = new CSVWriter(new OutputStreamWriter(entityStream, StandardCharsets.UTF_8));
final ImmutableSortedSet<String> sortedFields = ImmutableSortedSet.copyOf(
Iterables.concat(searchResponse.fields, Lists.newArrayList("source", "timestamp")));
// write field headers
csvWriter.writeNext(sortedFields.toArray(new String[sortedFields.size()]));
// write result set in same order as the header row
final String[] fieldValues = new String[sortedFields.size()];
for (ResultMessage message : searchResponse.messages) {
int idx = 0;
// first collect all values from the current message
for (String fieldName : sortedFields) {
final Object val = message.getMessage().get(fieldName);
fieldValues[idx++] = ((val == null) ? null : val.toString().replaceAll("\n", "\\\\n"));
fieldValues[idx++] = ((val == null) ? null : val.toString().replaceAll("\r", "\\\\r"));
}
// write the complete line, some fields might not be present in the message, so there might be null values
csvWriter.writeNext(fieldValues);
}
if (csvWriter.checkError()) {
LOG.error("Encountered unspecified error when writing message result as CSV, result is likely malformed.");
}
csvWriter.close();
}
}