org.graylog.plugins.views.search.export.SimpleMessageChunkCsvWriter Maven / Gradle / Ivy
/*
* Copyright (C) 2020 Graylog, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program 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
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* .
*/
package org.graylog.plugins.views.search.export;
import au.com.bytecode.opencsv.CSVWriter;
import org.graylog2.rest.MoreMediaTypes;
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;
import java.util.Arrays;
import java.util.List;
import static java.util.stream.Collectors.toList;
@Provider
@Produces(MoreMediaTypes.TEXT_CSV)
public class SimpleMessageChunkCsvWriter extends SimpleMessageChunkWriter {
private static final Logger LOG = LoggerFactory.getLogger(MessageBodyWriter.class);
@Override
public boolean isWriteable(Class type, Type genericType, Annotation[] annotations, MediaType mediaType) {
return typesMatch(type, genericType) && MoreMediaTypes.TEXT_CSV_TYPE.isCompatible(mediaType);
}
@Override
public void writeTo(
SimpleMessageChunk chunk,
Class type, Type genericType,
Annotation[] annotations,
MediaType mediaType,
MultivaluedMap httpHeaders,
OutputStream entityStream) throws IOException, WebApplicationException {
OutputStreamWriter writer = new OutputStreamWriter(entityStream, StandardCharsets.UTF_8);
try (CSVWriter csvWriter = new CSVWriter(writer)) {
writeHeaderIfFirstChunk(chunk, csvWriter);
writeValues(chunk, csvWriter);
if (csvWriter.checkError()) {
LOG.error("Encountered unspecified error when writing message result as CSV, result is likely malformed.");
}
}
}
private void writeHeaderIfFirstChunk(SimpleMessageChunk chunk, CSVWriter csvWriter) {
if (chunk.isFirstChunk()) {
csvWriter.writeNext(chunk.fieldsInOrder().toArray(new String[0]));
}
}
private void writeValues(SimpleMessageChunk chunk, CSVWriter csvWriter) {
List valueMatrix = valuesAsStringsInOrder(chunk);
csvWriter.writeAll(valueMatrix);
}
private List valuesAsStringsInOrder(SimpleMessageChunk simpleMessageChunk) {
return Arrays.stream(simpleMessageChunk.getAllValuesInOrder())
.map(this::toStringArray)
.collect(toList());
}
private String[] toStringArray(Object[] objects) {
return Arrays.stream(objects)
.map(o -> o == null ? null : o.toString())
.toArray(String[]::new);
}
}