Skip to content

Tag: java

Log4j2 log file not created

For a spring-boot application I’m trying to set up a log4j2 logger that will write the logs into a few sperate files, but the logs are only written to the console, I’ve checked my user_dir to make sure I’m not looking in the wrong location as well. This is the code that should write the test…

PrearedStatement executeUpdate() is not working

I’m new to JDBC and using the following code to update the row using MySQL JDBC driver. I have no idea why executeUpdate() is not updating the content in the database. Can anyone help me? Answer Your query string is wrong. It should be something like this: Look here for the proper syntax of update: http…

fragment binding (symbol “id” cannot be resolved)

I am trying to use the binding method in android studio to connect two fragments using onCreate and onViewCreated methods. so far i am getting id not resolved error. I have already connected the fragments on the xml graph. Bellow is the code of the settings java file. Answer Make sure to add this in build.gra…

Nullable PlanningVariable causes all null solution

I’ve a business case to assign resources(employees) to some work requirements. Here are three domain classes to describe the problem: And a PlanningEntity and PlanningSolution class defines as follows: The simplify the problem, I added only one Constraint which scores -1 * (requirement’s amount) i…

BitSet only grows with true bits and not false?

Currently with Java version “11.0.3” 2019-04-16 LTS on a Linux host (but would expect 8+ compatibility): in the context of computing a picture in order to send a binary bitmap to some hardware that only knows a 1-bit depth of display, I am using the BitSet for the first time and I get some disappo…

Regex to return all subdomains from a given domain

Given a domain string like aaaa.bbbb.cccc.dddd I am trying to iterate over all of its subdomains i.e. I thought this regex ((?:[a-zA-Z0-9]+.)*)([a-zA-Z0-9]+)$ should do the trick (please ignore the fact, that I am only matching these characters [a-zA-Z0-9]), however it only matches the full string. How can I …