javaAsync race conditionMedium

Inconsistent date formatting results in concurrent requests

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BugFind the bug and fix the code

What it should do

Convert a given date string to a formatted date string. Example: formatDate('2023-10-01') -> 'October 01, 2023'

What happens instead

Inconsistent date formatting results across multiple requests

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateFormatter {
    private static SimpleDateFormat dateFormat = new SimpleDateFormat("MMMM dd, yyyy");

    public static String formatDate(String dateStr) {
        try {
            Date date = dateFormat.parse(dateStr);
            return dateFormat.format(date);
        } catch (Exception e) {
            return "";
        }
    }
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the async and race conditions pattern

A missing await, unbuffered channel deadlocks, ConcurrentModificationException, and data races under load.

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import java.text.SimpleDateFormat; import java.util.Date; public class DateFormatter { private static SimpleDateFormat dateFormat = new SimpleDateFormat("MMMM dd, yyyy"); public static String formatDate(String dateStr) { try { Date date = dateFormat.parse(dateStr); return dateFormat.format(date); } catch (Exception e) { return ""; } } }

Inconsistent date formatting results in concurrent requests

What it should do

What happens instead

More async and race conditions to practise

Inconsistent date formatting results in concurrent requests

What it should do

What happens instead

More async and race conditions to practise