reading a whole date and time with spaces in a file-CodePudding

this question may have been asked before but didn't find any clue for my problem here,

here is my problem : I have a file that is like this :

abc fg Sat Jan 08 19:06:21 IST 2022 4 4.0

here is my code that reads from the file :



   BufferedReader read4 = new BufferedReader(new FileReader("shortDelvsFile.txt"));
      
      while ((s = read4.readLine()) != null) {
                          token = new StringTokenizer(s);
                          double str1 = Double.parseDouble(token.nextToken());
                          Integer str2 = Integer.parseInt(token.nextToken());
                          while (token.hasMoreTokens()) {
                              System.out.println(convert(token.nextToken()));
                          }
                          ShortDeliveries d = new ShortDeliveries(token.nextToken(), token.nextToken(),
                                  convert(token.nextToken()), str2, str1);
                          shortDelvss.add(d);
                      }
                      System.out.println("the short deliveries are : "   shortDelvss);
      
                      read4.close();

  // this function is to convert the string to date
  public static Date convert(String s) throws ParseException {
      Date date = new SimpleDateFormat("E MMM dd HH:mm:ss z yyyy", Locale.ENGLISH).parse(s);
      System.out.println(date);
      return date;
}

now i want each ``token.nextToken();``` inside the ShortDeliveries to be like this:

token.nextToken() = fg
convert(token.nextToken()) = Sat Jan 08 19:06:21 IST 2022
str1 = 4
str2 = 4.0;```

the problem is that in convert(token.nextToken()) it doesn't take the whole date because tokenizer reads until the first space how can i fix that?

CodePudding user response：

In case you know the date will always start with the day of week (e.g. Sat, Sun...), you can create a method to check if the current token is a known day. In case this is a week day, collect the following 6 tokens (or whatever tokens count you need to form a valid date) and send them together as String to your convert method.

if (isDayOfWeek(token)) {
   List<String> dateTokens = getNextTokens(token, 6);
   String dateString = String.join(" ", dateTokens);
   Date date = convert(dateString);
}


private boolean isDayOfWeek(String dayString) {
  Locale locale = Locale.getDefault();
  return Arrays.stream(DayOfWeek.values())
                .map(day -> day.getDisplayName(TextStyle.SHORT, locale))
                .anyMatch(dayString::equals);
}


private List<String> getNextTokens(StringTokenizer token, int tokenCount) {
  return IntStream.rangeClosed(1, tokenCount)
                .mapToObj(i ->token.nextToken())
                .collect(Collectors.toList());
}

CodePudding user response：

"s" is just a string that represents one line of your data

If you process it like a variable instead of a stream, you can use split.

There are several ways to do this, my preferences is as follows:

String parts_of_s = s.split(" ");

String s1 = s[0]; // you can in-line converting to double as you did above
String s2 = parts_of_s[1];

String remaining_string = s.substring(s1.length() 1   s2.length() 1); // length indexes at zero

String string_date = remaining_string.substring(0, 28); // since you know how many characters there are in the format

String s3 = parts_of_s[8];
String s4 = parts_of_s[9];

If you're dealing with super-long lines of data where efficiency matters (you probably won't), you could pursue other avenues:

read the next 28 characters
read the next 6 tokens and concatenate with a space