在CSV数据中将字符串解析为小时

Question

I have been trying to parse the String I got from the CSV file and convert the column "start" to hour. Here is my code:

public class BeerSong {


    private static final String csvFileName = "HourList201403.csv";
    public static void main (String[] args) throws IOException, java.text.ParseException {        

        CSVReader csvReader = new CSVReader(new FileReader(csvFileName));
        List<String[]>allLine = csvReader.readAll();

        SimpleDateFormat start = new SimpleDateFormat("HH:mm");
        Calendar calendar = GregorianCalendar.getInstance();
        int startH;
        Date startHour;
        for (String[] line : allLine) {
            startHour=start.parse(line[3]);
            calendar.setTime(startHour);
            startH = calendar.get(Calendar.HOUR);
            System.out.println(line[3]+", "+line[4]);
            System.out.println("Work: "+startH);            
        }
    }
}

When I try to run, it outputs an error:

Exception in thread "main" java.text.ParseException: Unparseable date: "Start"

So, what am I doing wrong here and how to fix this ?

The CSV format is like this, it has a lot rows so I put some here:

Person Name, Person ID, Date, Start, End
Scott Scala, 2, 2.3.2014, 6:00, 14:00
Janet Java, 1, 3.3.2014, 9:30, 17:00
Scott Scala, 2, 3.3.2014, 8:15, 16:00
Larry Lolcode, 3, 3.3.2014, 18:00, 19:00

Answer 1

The java.text.ParseException is thrown on attempting to parse the string "Start" as a Date .

Clearly that's the header of your spreadsheet, so you should skip the first row (note index 1 here):

 for (int i = 1; i < allLine.size(); i++) {

Note that you'll need the rest of the fields in your column 3 to consistently be of format HH:mm , ie not empty, etc.

The trick here is to either use fast-enumeration and skipping the first line, or as I display above, use an int -based iteration starting at index 1 (collections are 0-based, so that'll skip the first item).

Answer 2

You run through all of the parsed lines in your loop. The first line is: Person Name, Person ID, Date, Start, End . So the 4th item which you want to read out with: startHour=start.parse(line[3]); is Start . I think you have to skip the first line in your loop with:

for(int i = 1; i < allLine.size(); i++){ String[] line = allLine.get(i);