/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.avro.tool;
import java.io.File;
import java.io.InputStream;
import java.io.PrintStream;
import java.util.List;
import org.apache.avro.Schema;
import org.apache.avro.file.FileReader;
import org.apache.avro.file.DataFileReader;
import org.apache.avro.io.DatumWriter;
import org.apache.avro.generic.GenericDatumReader;
import org.apache.avro.generic.GenericDatumWriter;
import org.apache.avro.io.EncoderFactory;
import org.apache.avro.io.JsonEncoder;
/** Reads a data file and dumps to JSON */
public class DataFileReadTool implements Tool {
@Override
public String getName() {
return "tojson";
}
@Override
public String getShortDescription() {
return "Dumps an Avro data file as JSON, one record per line.";
}
@Override
public int run(InputStream stdin, PrintStream out, PrintStream err,
List<String> args) throws Exception {
if (args.size() != 1) {
// Unlike other commands, "-" can't be used for stdin, because
// we can only use seekable files.
err.println("Expected 1 argument: input_file.");
return 1;
}
GenericDatumReader<Object> reader = new GenericDatumReader<Object>();
FileReader<Object> fileReader =
DataFileReader.openReader(new File(args.get(0)), reader);
try {
Schema schema = fileReader.getSchema();
DatumWriter<Object> writer = new GenericDatumWriter<Object>(schema);
JsonEncoder encoder = EncoderFactory.get().jsonEncoder(schema, out);
for (Object datum : fileReader) {
encoder.configure(out); //reinitializes state
writer.write(datum, encoder);
encoder.flush();
out.println();
}
out.flush();
} finally {
fileReader.close();
}
return 0;
}
}