CSVParser将LF处理为CRLF [英] CSVParser processes LF as CRLF
问题描述
我正在尝试如下解析CSV文件
I am trying to parse a CSV file as below
String NEW_LINE_SEPARATOR = "\r\n";
CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR);
FileReader fr = new FileReader("201404051539.csv");
CSVParser csvParser = csvFileFormat.withHeader().parse(fr);
List<CSVRecord> recordsList = csvParser.getRecords();
String NEW_LINE_SEPARATOR = "\r\n";
CSVFormat csvFileFormat = CSVFormat.DEFAULT.withRecordSeparator(NEW_LINE_SEPARATOR);
FileReader fr = new FileReader("201404051539.csv");
CSVParser csvParser = csvFileFormat.withHeader().parse(fr);
List<CSVRecord> recordsList = csvParser.getRecords();
现在，文件中的普通行以CRLF字符结尾，但是对于少数几行，中间还有其他LF字符出现. 即
Now the file got normal lines ending with CRLF characters however for few lines there is additional LF character appearing in middle. i.e.
a,b,c,dCRLF --line1
e,fLF,g,h,iCRLF --line2
由于这个原因，解析操作创建了三个记录，而实际上它们只有两个.
Due to this, the parse operation creates three records whereas actually they are only two.
有没有办法让LF字符出现在第二行的中间而不被视为换行符，并且仅在解析时才获得两条记录?
Is there a way I can get the LF character appearing in middle of second line not treated as line break and get two records only upon parsing?
谢谢
推荐答案
我认为 uniVocity-parsers 是您将发现的唯一一个可以按预期使用行尾的解析器.
I think uniVocity-parsers is the only parser you will find that will work with line endings as you expect.
使用univocity解析器的等效代码为:
The equivalent code using univocity-parsers will be:
CsvParserSettings settings = new CsvParserSettings(); //many options here, check the tutorial
settings.getFormat().setLineSeparator("\r\n");
settings.getFormat().setNormalizedNewline('\u0001'); //uses a special character to represent a new record instead of \n.
settings.setNormalizeLineEndingsWithinQuotes(false); //does not replace \r\n by the normalized new line when reading quoted values.
settings.setHeaderExtractionEnabled(true); //extract headers from file
settings.trimValues(false); //does not remove whitespaces around values
CsvParser parser = new CsvParser(settings);
List<Record> recordsList = parser.parseAllRecords(new File("201404051539.csv"));
如果将行分隔符定义为\ r \ n，则这是唯一标识新记录的字符序列(用引号引起来).所有值都可以具有\ r或\ n而不用引号引起来，因为这不是行分隔符序列.
If you define a line separator to be \r\n then this is the ONLY sequence of characters that should identify a new record (when outside quotes). All values can have either \r or \n without being enclosed in quotes because that's NOT the line separator sequence.
解析输入样本时提供的信息:
When parsing the input sample you gave:
String input = "a,b,c,d\r\ne,f\n,g,h,i\r\n";
parser.parseAll(new StringReader(input));
结果将是:
LINE1 = [a, b, c, d]
LINE2 = [e, f
, g, h, i]
披露:我是这个图书馆的作者.它是开源且免费的(Apache 2.0许可证)
Disclosure: I'm the author of this library. It's open-source and free (Apache 2.0 license)
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