Is there a way to improve BigInteger performance with caching? When you operate on BigInteger it always creates a new BigInteger. For example, when you multiply two big integers, a new BigInteger is created to host the result. I want to use some mutable version of a BigInteger that will update one of the fiel…
Understanding Dao-pattern, can it be used for retrieving data from cache?
I read about DAO-pattern in the official documentation and it’s not quite clear if it can be used for retrieving data from cache? Formally speaking, DAO is an additional abstraction layer between clients and mechanism the data is being retrieved from somewhere. So, if data resides in cache, I suppose we…
UNIQUE constraint failed: sqlite database : android
I am trying to insert values in table. But there is only one value inserted. I am getting an error in log cat when I am trying to insert new values. Log cat shows : Its showing error on these two lines while inserting row. EventTableHelper How to solve this?? Answer Your code probably violates primary keyR…
Merge sets when two elements in common
This is the follow up of compare sets I have I want to merge the sets when there are two elements in common. For example 0,1,2 and 0,2,6 has two elements in common so merging them to form [0,1,2,6]. Again [0,1,2,6] and [2,6,7] has 2 and 6 common. so merging them and getting [0,1,2,6,7]. The final output shoul…
How can I run Kotlin-Script (.kts) files from within Kotlin/Java?
I noticed that IntelliJ can parse .kts files as Kotlin and the code editor picks them up as free-floating Kotlin files. You are also able to run the script in IntelliJ as you would a Kotlin file with a main method. The script executes from top to bottom. This form is PERFECT for the project I’m working …
How to convert String to its resource ID (Android Studio)
I have an xml string in my values/strings.xml file And I have the String “150” in my controller MainActivity.java. In my MainActivity, how can I convert that String to the resource ID of the pokemon_d String in the xml file? Is this even possible? Answer You can not get identifier by value, but yo…
Is there a way to reference the Java class for a Kotlin top-level function?
I want to load a resource in a top level function using Class.getResourceAsStream(). Is there any way to get a reference to the class that the top level function will be compiled into so that I can write, for example Answer Another way I found is to declare a local class or an anonymous object inside a top le…
Can we fetch the results using one RowMapper object instead of creating objects everytime?
When fetching results from database through SpringJdbcTemplate, everywhere I have seen that they are passing the new object of RowMapper` every time. Is this required? Or can we just use one object and pass it again and again? Example: I know this object will be garbage collected later on, but I didn’t …
How to add Business hours to Date considering not adding weekends ? – Java
I want to add certain number of hours to date, ignoring the weekends For example, (Friday 18:00) + 48 = (Tuseday 18:00) (Saturday and Sunday are ignored) since the company works 24 hours, business hours are 24. But still i could not get how to add hours only on business days function can be something like: An…
Android: java.lang.NullPointerException: Attempt to invoke virtual method ‘java.lang.String java.lang.Object.toString()’ on a null object reference
Facing a problem with a practice app I’m working on. I’m facing a NullPointerException problem relating to the toString method. Being new to android app development, I’m unsure of the exact cause even after my research into this. Hence I ask for someone who is more familiar with the stack tr…