I’ve read the documentation, but I still can’t get when I should use one or the other: OffsetDateTime ZonedDateTime According to documentation OffsetDateTime should be used when writing date to database, but I don’t get why. Answer Q: What’s the difference between java 8 ZonedDateTime …
Why does Stream.allMatch() return true for an empty stream?
My colleague and I had a bug that was due to our assumption that an empty stream calling allMatch() would return false. Of course, it is kind of our fault for assuming and not reading documentation. But what I don’t understand is why the default allMatch() behavior for an empty stream returns true. What…
Reflecting a class with only package level access
I’m not quite sure how to go about reflecting a class that only has package-level access. I know how to reflect any class that has public access, but I cannot figure out how to reflect the following …
Is it possible to simulate connection timeout using wiremock tools?
I know that it can simulate SocketTimeoutException by using withFixedDelay, but what about ConnectionTimeoutException? Answer Yes it is possible to do this with WireMock by calling addDelayBeforeProcessingRequests(300) against the Java API or posting the following to http://<host>:<port>/__admin/s…
Spring Batch Item Reader is executing only once
Trying to implement Spring batch,but facing a strange problem,Our ItemReader class is executing only once. Here below is the detail. If we have 1000 rows in DB. Our Item reader fetch 1000 rows from DB,and pass list to ItemWriter ItemWriter successfully delete all items. Now ItemReader again tries to fetch the…
java.lang.NoSuchMethodError: com.sun.mail.util.TraceInputStream
I’m trying to send an email through Java Mail API and it works fine on my laptop. When I’m doing exactly the same in Heroku, I’m getting this: Here is what I have in pom.xml: I guess there is another version of Java Mail API inside Heroku JDK, which doesn’t have this constructor……
Where is the Balance Between Dependency Injection and Abstraction?
Many Architects and Engineers recommend Dependency Injection and other Inversion of Control patterns as a way to improve the testability of your code. There’s no denying that Dependency Injection …
How to sum a list of integers with java streams?
I want to sum a list of Integers. It works as follows, but the syntax does not feel right. Could the code be optimized? Answer This will work, but the i -> i is doing some automatic unboxing which is why it “feels” strange. mapToInt converts the stream to an IntStream “of primitive int-va…
JSR-310 – parsing seconds fraction with variable length
Is there a way how to create JSR-310 formatter that is able to parse both following date/times with variable length of seconds fraction? or Example code: Answer This solves the problem: The answer by JiriS is incorrect, as it uses appendValue whereas the correct way is to use DateTimeFormatterBuilder.appendFr…
If I use string.contains() on a string that may have regular expressions [closed]
Closed. This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 1 year ago. Improve this question If I use string.contains() on a string that may have regular expressions, will the regular ex…