uniVocity-parsers を使用すると、固定幅の入力を読み取るだけでなく、マスター/ディテール行 (行にサブ行がある) も読み取ることができます。
次に例を示します。
//1st, use a RowProcessor for the "detail" rows.
ObjectRowListProcessor detailProcessor = new ObjectRowListProcessor();
//2nd, create MasterDetailProcessor to identify whether or not a row is the master row.
// the row placement argument indicates whether the master detail row occurs before or after a sequence of "detail" rows.
MasterDetailListProcessor masterRowProcessor = new MasterDetailListProcessor(RowPlacement.TOP, detailProcessor) {
@Override
protected boolean isMasterRecord(String[] row, ParsingContext context) {
//Returns true if the parsed row is the master row.
return row[0].startsWith("B");
}
};
FixedWidthParserSettings parserSettings = new FixedWidthParserSettings(new FixedWidthFieldLengths(4, 5, 40, 40, 8));
// Set the RowProcessor to the masterRowProcessor.
parserSettings.setRowProcessor(masterRowProcessor);
FixedWidthParser parser = new FixedWidthParser(parserSettings);
parser.parse(new FileReader(yourFile));
// Here we get the MasterDetailRecord elements.
List<MasterDetailRecord> rows = masterRowProcessor.getRecords();
for(MasterDetailRecord masterRecord = rows){
// The master record has one master row and multiple detail rows.
Object[] masterRow = masterRecord.getMasterRow();
List<Object[]> detailRows = masterRecord.getDetailRows();
}
開示：私はこのライブラリの作成者です。オープンソースで無料です (Apache V2.0 ライセンス)。