MessageConversionException occurred when mapping string date to LocalDateTime

Question

I have a queue that listens to a topic and my listener receives a DTO. I need to parse the String to LocalDateTime but I'm getting this error

org.springframework.messaging.converter.MessageConversionException: Could not read JSON: Text '2020-06-18 11:12:46' could not be parsed at index 10

Here is the message details

{"id":444, "details":{"TYPE":[1]},"dateOccurred":"2020-06-18 11:12:46"}"] 

And here is how I set it in my DTO

public class PlanSubscriptionDto {
    private Long id;

    private Map<String, List<Long>> details;

    private LocalDateTime dateOccurred;

    public void setDateOccurred(String dateTime) {
        this.dateOccurred = LocalDateTime.parse(dateTime, DateTimeFormatter.ISO_DATE_TIME);
//ive also tried this
//this.dateOccurred = LocalDateTime.parse(dateTime, DateTimeFormatter.ofLocalizedDateTime(FormatStyle.LONG));
    }
}

Thank you for your help! Any advice would we great.

Answer 1

Use a format pattern string to define the format.

public class PlanSubscriptionDto {
    private static final DateTimeFormatter FORMATTER
            = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss");

    private Long id;

    private Map<String, List<Long>> details;

    private LocalDateTime dateOccurred;

    public void setDateOccurred(String dateTime) {
        this.dateOccurred = LocalDateTime.parse(dateTime, FORMATTER);
    }
}

Why didn’t your code work?

ISO 8601 format has a T between the date and the time. There’s no T in your date-time string, so DateTimeFormatter.ISO_DATE_TIME cannot parse it.

Variants

Now we’re at it, I’d like to show a couple of other options. Taste differs, so I can’t tell which one you’ll like the best.

You may put in the T to obtain ISO 8601 format. Then you will need no explicit formatter. The one-arg LocalDateTime.parse() parses ISO 8601 format.

    public void setDateOccurred(String dateTime) {
        dateTime = dateTime.replace(' ', 'T');
        this.dateOccurred = LocalDateTime.parse(dateTime);
    }

Or sticking to the formatter and the space between date and time, we can define the formatter in this wordier way:

    private static final DateTimeFormatter FORMATTER = new DateTimeFormatterBuilder()
            .append(DateTimeFormatter.ISO_LOCAL_DATE)
            .appendLiteral(' ')
            .append(DateTimeFormatter.ISO_LOCAL_TIME)
            .toFormatter();

What we get for the extra code lines is (1) more reuse of built-in formatters (2) this formatter will accept time without seconds and time with a fraction of second too because DateTimeFormatter.ISO_LOCAL_TIME does.

Link

Wikipedia article: ISO 8601