在Jenkins中，DateFormat UnitTest失败，但本地失败

Question

I've made a unit-test of a Service, when I execute the Jenkins job, every test method pass correctly, except one.
But this test method, works on my machine, both with Eclipse and using the mvn command.

    // TARGET_RUN_DATE_OF_YEAR = "2018-01-01"
    @Test
    public void dateToTimestamp() {
        Service service = getService();

        String df = "YYYY-MM-dd";
        String invalid = "INVALID";

        // Check success
        Timestamp timestamp = service.dateToTimestamp(TARGET_RUN_DATE_OF_YEAR, df);
        Assert.assertEquals(service.getTodayTimestamp(), timestamp); // <-- Fail here
        // Check failure
        Assert.assertNull(service.dateToTimestamp(TARGET_RUN_DATE_OF_YEAR, invalid));
        Assert.assertNull(service.dateToTimestamp(invalid, df));
    }

The Service have mulitple methods:

• getTodayTimestamp give today Timestamp, this method is tested, it works on my machine and on Jenkins.
• dateToTimestamp takes a date and a dateFormat as Strings, and returns the date as a Timestamp, this method is the one not working.

The dateToTimestamp method in the Service:

    private Timestamp dateToTimestamp(String date, DateFormat df) throws ParseException {
        return new Timestamp(df.parse(date).getTime());
    }

    @Override
    public Timestamp dateToTimestamp(String date, String dateFormatString) {
        try {
            DateFormat df = new SimpleDateFormat(dateFormatString);
            return dateToTimestamp(date, df);
        } catch (Exception e) {
            log.warn("Exception during conversion of date to timestamp, exception : {}", e);
            return null;
        }
    }

As I previously said, the test work perfectly on my pc, but not on Jenkins (adding the @Ignore annotations to this method, makes the job successful).
When launching the job, I get this error:

Failed tests: dateToTimestamp(com.test.service.ServiceImplTest): expected:<2018-01-01 00:00:00.0> but was:<2017-12-31 00:00:00.0>

What I can assure, is that even in Jenkins, the dateToTimestamp method takes the parameters TARGET_RUN_DATE_OF_YEAR , which is "2018-01-01" and the dateFormart String as "YYYY-MM-dd" . But still returns 2017-12-31 00:00:00.0 as Timestamp.

Any ideas?

Answer 1

java.time

I am assuming that you wanted a Timestamp for use with your SQL database. Don't use Timestamp for that in 2019. That class is poorly designed and long outdated.

• If the datatype on the SQL side is timestamp with time zone (which it should be for a timestamp), use OffsetDateTime in Java.
• If on the SQL side you need a mere timestamp (without time zone), use LocalDateTime in Java.

Code example:

    String dateString = "2018-01-01";
    OffsetDateTime odt = LocalDate.parse(dateString)
            .atStartOfDay()
            .atOffset(ZoneOffset.UTC);

    System.out.println(odt);

Output is:

2018-01-01T00:00Z

Now you can pass your OffsetDateTime to JDBC using something like:

    yourPreparedStatement.setObject(4, odt);

What went wrong in your code?

I believe that you are experiencing the combination of two issues:

• Using uppercase YYYY in your format pattern string is incorrect. Uppercase Y is for week based year and only useful with a week number. With the old and troublesome SimpleDateFormat you would have needed lowercase y for year.
• (The JVMs on) your machine and the Jenkins server have different default locales.

To demonstrate:

    String dateString = "2018-01-01";
    String dateFormatString = "YYYY-MM-dd"; // Incorrect format pattern string
    DateFormat df = new SimpleDateFormat(dateFormatString);
    System.out.println(df.parseObject(dateString));

Output on my computer (Danish locale, Europe/Copenhagen time zone):

Mon Jan 01 00:00:00 CET 2018

However if I first do this:

    Locale.setDefault(Locale.US);

— then the output from the above snippet is different, namely:

Sun Dec 31 00:00:00 CET 2017

What happens is that SimpleDateFormat gives up on determining an exact date from week based year, month and day of month and instead just gives you the first date of the week based year. It's typical behaviour of SimpleDateFormat to give you a result that cannot be right and nevertheless pretend that all is well. In some locales the week begins on Monday, and you get Mon Jan 01, which coincidentally agrees with your string. In other locales, such as the US, the week starts on Sunday, so instead you get Sun Dec 31 of the previous year.

Link

• Oracle tutorial: Date Time explaining how to use java.time.
• Related question about uppercase Y for year: java parsing string to date