Collectives™ on Stack Overflow

Find centralized, trusted content and collaborate around the technologies you use most.

Teams

Q&A for work

Connect and share knowledge within a single location that is structured and easy to search.

I am reading a csv file using opencsv.

I am ignoring the first line of; the csv file is tab separated with some values enclosed in double quotes.

The problem occurs when I read the values of a column that has the '\' character, this is stripped out of the value.

reader = new CSVReader(new FileReader(exchFileObj),'\t','"',1);
For example in original file:
address = 12\91buenosaires   
It becomes as:
address = 1291buenosiares
In the string array that csvreader generates. How do I modify it to be able to read the '\' character also?
                If opencsv uses the \` as escape character, you might need to enter \\\` in your file. If you cannot, can you set a different escape character in open csv?
– rsp
                May 15, 2011 at 12:42
I had the same problem and couldn't find another character I could guarantee wouldn't show up in my csv file.  According to a post on sourceforge though, you can use the explicit constructor with a '\0' to indicate that you don't want any escape character.  
http://sourceforge.net/tracker/?func=detail&aid=2983890&group_id=148905&atid=773542
CSVParser parser = new CSVParser(CSVParser.DEFAULT_SEPARATOR, CSVParser.DEFAULT_QUOTE_CHARACTER, '\0', CSVParser.DEFAULT_STRICT_QUOTES);
I did a bit of cursory testing, and this seems to work just fine, at least backslashes certainly make it through.  
                i am using kotlin, and passing '\0' to CSVWriter as escape character gives invalid escape character error.  Is there any other way to avoid the escape character? My work around is using ' ',  which is working but it adds an unnecessary space
– Bosco
                Aug 19, 2022 at 1:03
                What if I want my CSV to support any Unicode character? Sounds like just a workaround to a bug in the library.
– Mihai Danila
                Aug 2, 2019 at 15:15
                The link is now broken. I could not find any constructor in which you can set the escape character - opencsv.sourceforge.net/apidocs/com/opencsv/CSVReader.html
– Ravindra Gullapalli
                Nov 17, 2020 at 10:26
                @RavindraGullapalli from version 5 the idea is to use the builder pattern, see opencsv.sourceforge.net/#configuration
– rsp
                Nov 17, 2020 at 15:18
Note: I think the solution in this answer is better than the three alternatives in that it configures a compliant reader in a coarse-grained manner, by relying on the RFC. The other answers go into the details of configuring an escape character. While that works, it seems more like a white-box solution.
By default, OpenCSV's reader does not comply with the writer. The reader is not RFC-compliant. Don't ask me why that is, as I find it as troubling and perplexing as you.
The solution is for you to configure your CSVReader with an RFC-compliant parser:
RFC4180Parser rfc4180Parser = new RFC4180ParserBuilder().build();
CSVReaderBuilder csvReaderBuilder =
  new CSVReaderBuilder(new StringReader(writer.toString()))
      .withCSVParser(rfc4180Parser);
reader = csvReaderBuilder.build();
Here is the source page for the above.
In addition to @JMM 's answer, you have to use this created CSVParser in the constructor of the CSVReader. The only available constructor is:
public CSVReader(Reader reader, int line, CSVParser csvParser)
You can set the line to 0 so that it will not skip anything
        
Thanks for contributing an answer to Stack Overflow!
Please be sure to answer the question. Provide details and share your research!
But avoid …
Asking for help, clarification, or responding to other answers.
Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.