How to Resolve Java's Unparseable Date Exception

How can I fix an "unparseable date exception" in Java?

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
String dateString = "2023-10-05";
try {
    Date date = sdf.parse(dateString);
} catch (ParseException e) {
    e.printStackTrace();
}

The "unparseable date exception" in Java is a common error that arises when attempting to convert a string into a date format that does not match the expected pattern. This guide will help you understand the causes and provide solutions to effectively troubleshoot this issue.

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", Locale.US);
String dateString = "2023-10-05";
try {
    Date date = sdf.parse(dateString);
    System.out.println(date);
} catch (ParseException e) {
    System.err.println("Date parsing failed: " + e.getMessage());
}

Causes

• The date string format does not match the defined pattern.
• The input date string contains invalid date values (e.g., February 30).
• Incorrect locale settings that affect date parsing.

Solutions

• Ensure that the string's date format exactly matches the SimpleDateFormat pattern you've defined.
• Validate the date string before parsing it to ensure it contains valid date values.
• Set the appropriate Locale in SimpleDateFormat to avoid parsing errors caused by regional differences. Example: SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", Locale.US);

Mistake: Using a date format that does not consider leading zeros (e.g., using "MM/dd/yyyy" for dates like 03/05/2023).

Solution: Ensure that the format exactly matches the input string's format, including leading zeros when necessary.

Mistake: Not handling parsing exceptions properly, causing undetected errors in the application.

Solution: Always wrap your parsing code in try-catch blocks to gracefully handle exceptions.