How can i create a list of List from Array eg: int[] arr = {3, 1, 5, 8, 2, 4}. Such that the lists in the List have only two elements eg: [[3,1], [5,8], [2,4]]. So far i have tried code below but it return only lists with one element,I can’t figure out where i went wrong. Result: [[3], [1],
Spring Boot get JSON Error representation in the ErrorController
Spring Boot provides errors in the json format like this: Is it possible for me to obtain this error inside the ErrorController and to proceed with it? Is it inside the HttpServletResponse or maybe something else? Answer The default error attributes are extracted from a WebRequest using the ErrorAttributes bean. Spring already provided a default implementation of this bean, the
How to setup Kafka Idempotent Producer in Spring Boot?
We would like to store data in Kafka using exactly-once semantics in order to avoid message duplication. Producer with following properties: Kafka topic description: Integration test: Our expectation is that only one message should be stored in Kafka, but the actual result 3 messages. How can I make excatly-once semantics to work with Kafka? What is missing in my configuration?
How to get perfect UTC Time in java/android?
I am trying to get UTC time in my application but unfortunately every time I am getting my current emulator Date and Time Instead of UTC. Tried, Calendar cal = Calendar.getInstance(TimeZone.getTimeZone(“UTC”)); ZonedDateTime utcTime = ZonedDateTime.now(ZoneOffset.UTC); DateTime now = DateTime.now(DateTimeZone.UTC); My code: Any help highly appreciated. Answer Try this code:
simple java program returning incorrect value
Hello I am brushing up on Java practice. I have this very simple program: There are two int values, along with a boolean variable. i) The program will return true if one of these values is negative and one is positive. ii) However, if the boolean variable is true, the program can only return true if both int values are
Does anyone know why @Valid fails with javax.validation and works with spring starter validation
I have the following controller: which uses this dependency, among others: the LibraryEvent DTO looks like this: And the book inside that library event, is the following: I also have this test which uses MockMvc to send a mocked request to the controller in order to test that one: Everything is fine so far, the problem is that in my
Difficulty trying to sort 10 numbers inputted by a user. Must use arrays and a separate method for sorting
My program isn’t sorting the numbers at all. It displays them in the order they were initially entered. It must sort them from smallest to largest number. The code below should find the largest number in the array and swap it with the last .the code is below: Answer I believe your problem is here: array.length is not less than
How to randomize ArrayList without using Collections.swap()?
I was asked to create a method that randomly rearranges my list which contains arrays. The list contains multiple persons and their names and surnames. My question is how do I move a person (array containing two elements name and surname inside the list) to a different index without using the method swap()? Because our list does not support that
Shared Dependency for two Deployments on Wildfly
I have two webapps, which are deployed within the same wildfly. Both webapps should share certain libraries, which are not part of the wildfly modules. To keep the deployment non-dependent on the specific wildfly, I would prefer not to provide the shared libraries via the wildfly-module system (I am aware, it is possible to user-define modules). My approach was to
How to customize expireAfterWrite for concrete cache if I use cacheBuilder?
Based on this answer I try to use customized expireAfterWrite for “customCache” So my config look like this: Then in codeBase I use: “customCache” And based on my experiments it keeps values on cache pnly 60 seconds by I expect 60 minutes. How to achieve desired result ? Answer I think a better way to do this is as follows.