com.netflix.astyanax.util.CsvColumnReader Maven / Gradle / Ivy
/*******************************************************************************
* Copyright 2011 Netflix
*
* 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 com.netflix.astyanax.util;
import java.io.IOException;
import java.io.Reader;
import java.util.ArrayList;
import java.util.List;
import org.apache.cassandra.utils.Pair;
import org.apache.commons.csv.CSVParser;
/**
* Read a CSV where each row represents a single column
*
* rowkey, columname, columnvalue
*
* @author elandau
*
*/
public class CsvColumnReader implements RecordReader {
private CSVParser parser;
private boolean hasHeaderLine = true;
public CsvColumnReader(Reader reader) {
this.parser = new CSVParser(reader);
}
public CsvColumnReader setHasHeaderLine(boolean flag) {
this.hasHeaderLine = flag;
return this;
}
@Override
public void start() throws IOException {
// First line contains the column names. First column expected to be the
// row key
if (hasHeaderLine) {
parser.getLine();
}
}
@Override
public void shutdown() {
}
@Override
public List> next() throws IOException {
// Iterate rows
String[] row = parser.getLine();
if (null == row)
return null;
List> columns = new ArrayList>();
// Build row mutation for all columns
columns.add(Pair.create("key", row[0]));
if (row.length == 3)
columns.add(Pair.create(row[1], row[2]));
return columns;
}
}