I’m solving Codility questions as practice and couldn’t answer one of the questions. I found the answer on the Internet but I don’t get how this algorithm works. Could someone walk me through it step-by-step? Here is the question: And here is the solution I found with my comments about parts…
Gradle project error – java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication
This is my main application code: I’m using gradle to build the project. Even though SpringApplication file is properly imported I’m getting the following error: I’m getting following gradle message when I hover over SpringApplication Any help would be much appreciated. Thanks in advance! An…
JavaFX search in listview
I want to search in listview and my code is working but not well enough. The problem is when i write few characters in the search text field not only the result appears, but the rest of the items also appear… The code: Photos: Original list: Sorted list: ListCell implementation: Answer Your problem is n…
Jackson error “Illegal character… only regular white space allowed” when parsing JSON
I am trying to retrieve JSON data from a URL but get the following error: My code: The url constructed is i.e https://www.example.org/api/search.json?keywords=iphone&count=50 What is going wrong here? And how can I parse this data successfully? Imports: example response Answer The message should be pretty…
How to merge multiple rectangles into one polygon
I am struggling with this part of my task at work. I’ve deliberately not detailed the context of the work task to try and keep the focus on the problem. I have to merge rectangles into a single polygon as shown in the attached image, but I need the list of points so that I can write these out into
NoSuchMethodError in shapeless seen only in Spark
I am trying to write a Spark connector to pull AVRO messages off a RabbitMQ message queue. When decoding the AVRO messages, there is a NoSuchMethodError error that occurs only when running in Spark. I could not reproduce the Spark code exactly outside of spark, but I believe the two examples are sufficiently …
Cannot change dependencies of configuration ‘:compile’ after it has been resolved
I have a simple java project that uses json.jar library. gradle.build file content is: problem is when I want to add json to my classpath and use it, this error happens how can I solve this? Answer First, you have to add a repositories block to specify where dependencies are retrieved from (usually before dep…
Run a Maven Project using IntelliJ IDEA
I’m new to IntelliJ IDEA and I would like to run a simple Maven Quickstart project using it. I followed all the instructions, the project was sucessfully built. But when I try to compile and run it , the Run button is not activated. It looks like IntelliJ IDEA couldn’t figure out where the main cl…
Java – How to handle special characters when compressing bytes (Huffman encoding)?
I am writing a Huffman Compression/Decompression program. I have started writing my compression method and I am stuck. I am trying to read all bytes in the file and then put all of the bytes into a byte array. After putting all bytes into the byte array I create an int[] array that will store all the frequenc…
When should I use streams?
I just came across a question when using a List and its stream() method. While I know how to use them, I’m not quite sure about when to use them. For example, I have a list, containing various paths to different locations. Now, I’d like to check whether a single, given path contains any of the pat…