Supercsv reading/writing CSV and TSV file instance tutorial

First, let's briefly introduce the differences between CSV and TSV files:

TSV, short for Tab-separated values, that is, Tab-separated values. For TSV standards, see: http://en.wikipedia.org/wiki/Tab-separated_values CSV, Comma-separated values, that is, Comma-separated values. For CSV standards, see: http://en.wikipedia.org/wiki/Comma-separated_values

The project needs to organize the original tsv file data to form a more convenient new tsv File (add several columns ). It involves reading and writing tsv files. In fact, self-implementation is also very simple, but there is a ready-made toolkit supercsv, it is used to try. Address: http://supercsv.sourceforge.net/index.html

The documentation is clear and clear. There are actually many examples of parsing csv files using supercsv on the internet. However, the difference between tsv and csv shows that a complete set of code can be solved, if you change the separator, you will be hungry. In supercsv, it does. First attach the example of the official website: http://supercsv.sourceforge.net/examples_reading.html

Resolved csv file:

UstomerNo, firstName, lastName, birthDate, mailingAddress, married, numberOfKids, expiration, email, loyaltyPoints 1, John, Dunbar, 13/06/1945, "1600 Amphitheatre Parkway Mountain View, CA 94043 United States "," May the Force be with you. "-Star Wars", jdunbar@gmail.com, 0 2, Bob, Down, 25/02/1919, "1601 Willow Rd. menlo Park, CA 94025 United States ", Y, 0," Frankly, my dear, I don't give a damn. ""-Gone Wit H The Wind ", bobdown@hotmail.com, 123456 3, Alice, Wunderland, 08/08/1985," One Microsoft Way Redmond, WA 98052-6399 United States ", Y, 0," "Play it, sam. play "" As Time Goes. "-Casablanca", throughthelookingglass@yahoo.com, 2255887799 4, Bill, Jobs, 10/07/1973, "2701 San Tomas Expressway Santa Clara, CA 95050 United States", Y, 3, "You 've got to ask yourself one question:" "Do I feel lucky? "" Well, do ya, punk? ""-Dirty Harry ", billy34@hotmail.com, 36

Code parsed using MapReader:

The code is as follows:

Copy code

<Pre class = "brush: java"> /** * An example of reading using CsvMapReader. */ Private static void readWithCsvMapReader () throws Exception { ICsvMapReader mapReader = null; Try { MapReader = new CsvMapReader (new FileReader (CSV_FILENAME), CsvPreference. STANDARD_PREFERENCE );             // The header columns are used as the keys to the Map Final String [] header = mapReader. getHeader (true ); Final CellProcessor [] processors = getProcessors ();             Map & lt; String, Object & gt; customerMap; While (customerMap = mapReader. read (header, processors ))! = Null ){ System. out. println (String. format ("lineNo = % s, rowNo = % s, customerMap = % s", mapReader. getLineNumber (), MapReader. getRowNumber (), customerMap ));             }                 } Finally { If (mapReader! = Null ){ MapReader. close ();             } }} /** * Sets up the processors used for the examples. There are 10 CSV columns, so 10 processors are defined. Empty * Columns are read as null (hence the NotNull () for mandatory columns). ** @ return the cell processors */ Private static CellProcessor [] getProcessors (){ Final String emailRegex = "[a-z0-9. _] + @ [a-z0-9.] +"; // just an example, not very robust! StrRegEx. registerMessage (emailRegex, "must be a valid email address ");     Final CellProcessor [] processors = new CellProcessor [] { New UniqueHashCode (), // customerNo (must be unique) New NotNull (), // firstName New NotNull (), // lastName New ParseDate ("dd/MM/yyyy"), // birthDate New NotNull (), // mailingAddress New Optional (new ParseBool (), // married New Optional (new ParseInt (), // numberOfKids New NotNull (), // favouriteQuote New StrRegEx (emailRegex), // email New LMinMax (0L, LMinMax. MAX_LONG) // loyaltyPoints };     Return processors ;} </Pre>

I am afraid the code of the sample can no longer be clear. The delimiter is set through CsvPreference. STANDARD_PREFERENCE. To parse the TSV file, replace it with CsvPreference TAB_PREFERENCE.

Add source code:

The code is as follows:

Copy code

<Pre class = "brush: java"> /** * Ready to use configuration that shoshould cover 99% of all usages. */ Public static final CsvPreference STANDARD_PREFERENCE = new CsvPreference. Builder ('"'," rn "). build (); /** * Ready to use configuration for Windows Excel exported CSV files. */ Public static final CsvPreference EXCEL_PREFERENCE = new CsvPreference. Builder ('"'," n "). build ();   /** * Ready to use configuration for north European excel CSV files (columns are separated by ";" instead ",") */ Public static final CsvPreference EXCEL_NORTH_EUROPE_PREFERENCE = new CsvPreference. Builder ('"', ';'," n "). build ();   /** * Ready to use configuration for tab-delimited files. */ Public static final CsvPreference TAB_PREFERENCE = new CsvPreference. Builder ('"', 'T'," n "). build (); </Pre>