We are trying to preload images into cache memory to load them later (the images are located in the Asset folder of the application) What we tried: The issue: Images are cached only when we are trying to load/display them: They have to be loaded in memory before so that they appear faster. We also tried to us…
Build docker image with jetty – when should I build?
I’m working on ‘dockerizing’ a java web application (https://github.com/kermitt2/grobid) which I want to run using jetty. Here the Dockerfile: The current docker image works perfectly, but it requires the application to be built before (it cannot be built from the fresh git clone). For examp…
Need help on Java Swing JFrame
I’m very new to Swing and I need to build a JFrame that: Has an image on top. Below the image has 16 little images divided into 4 groups (4 “panels”), on the same “row”. Below those 16 images I need 4 “panels” on the same “row”. Every panel contains some h…
How to merge 3 sorted arrays into 1 sorted array in Big-O(N) time?
Trying to merge 3 arrays into one so that the final array is in order. Given Merge the arrays so that the final array d = {1,1,2,3,4,5} Can’t just concatenate them and then sort the d array because that would make the time complexity larger than Big-O(N). This is what I got so far. Having problems with …
Java – Slice any array at steps
In python we are able to do the following: Is there an equivalent to this in Java? I have been looking for this type of array slicing, but I have had no luck. Any help would be great, Thanks! Answer If you are using Java 8, then you can make use of streams and do the following: Outputs: [0, 3,
Mockito asks to add @PrepareForTest for the class even after adding @PrepareForTest
I have the following simple code. I have a class (TestClass) and I want to test “someMethod”. There is an external static method which is called by my “someMethod”. I want to Powermock that static method to return me some dummy object. I have the @PrepareForTest(ExternalClass.class) in…
netbeans dist folder jar not running [closed]
Closed. This question needs debugging details. It is not currently accepting answers. Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question. Closed 2 years ago. Improve this question I hav…
How to resolve “Caused by: org.postgresql.util.PSQLException: ERROR: relation “employee” does not exist Position: 13″ error?
I have tried to execute the Hibernate Demo application. I’m getting the below error message. Database: PostgreSQL Hibernate Version: 5 Source code for Bean class package com.javatpoint; Test class package com.javatpoint; hibernate.cfg.xml Error Message Eclipse Project PostgreSQL Database Answer Hibernat…
How to explicitly invoke default method from a dynamic Proxy?
Since Java 8 interfaces could have default methods. I know how to invoke the method explicitly from the implementing method, i.e. (see Explicitly calling a default method in Java) But how do I explicitly invoke the default method using reflection for example on a proxy? Example: Edit: I know a similar questio…
log4j2 change Rolling file appender max files programmatically
I am working on an application that uses log4j2 (initializes the parameters using log4j2.xml) and loads the logger. When the application runs, I am required to programmatically override a few parameters such as changing the log level and rolling file appender properties. I am able to change the log level usin…