I want to update the bitmap image inside the URL without changing its download URL in the real-time database because at uploading for the first time I have uploaded the image in the storage and stored it URL in the real time database now I want to update that image how should I approach this ?? above written code was
Is it possible to cast an instance of List<ArrayList> to List<List> in O(1) time in Java?
I have an instance of List<ArrayList<Integer>>, how can I change it to type List<List<Integer>> ? My solution is: However, this method takes time O(n), with n the length of list1. Question1: Is there better method? The following naive method is compile error: Question2: why is above method compile error? PS: It’s from a practical problem. I just simplify the production
Is it possible to hook thread creation?
I am making a plugin system and i need to see when a plugin calls Thread.start() Is there a way similar to Runtime.getRuntime().addShutdownHook but for hooking when a thread starts? Answer Byteman You can use Byteman to inject your own code into the thread.start() method. In fact, the first example to using Byteman with JVM classes on their website is
Map.ofEntries gives Null Pointer Exception on checking NULL key using containsKey()
I was fetching key from a constant map earlier using HashMap. On passing a NULL key at containsKey(), I used to get FALSE. To make the code look fancy, I tried java-8 over it. So, instead of HashMap, I started using Map.ofEntries to build my map Surprisingly, I got Null Pointer Exception when a Null key was passed to containsKey()
How can I provide this sort of String builder class?
I like to have a Drive class where all files and folders for a project are managed. My first attempt was pretty easy like a lot of functions (most of them with arguments). Now I try to make it more …
Trying to implement model batching for opengl not sure why it’s not showing anything
I am trying to implement model and sprite batching for a game engine I am working on, trying to test it on GUI Renderer but can’t get any results, errors or anything drawing to the screen am I doing something wrong I will link the Github page for the full code but here is the code for MeshBatch class and
how to stub a method in a class which is called from another class
I’m not able to get my method to return the desired value. Above implementations shows how I have written my test, but it’s not working. What am i doing wrong here? Answer Yet to clarify given answers: your mistake is that you do not actually use that spy/mock anywhere. In your class A you have a static method where a
Why is this program giving “division by zero” error?
Give one point to A[i] if either A[i]%A[j] ==0 or A[j]%A[i] == 0 Calculating the total points received by every element. Input: A={2,3,4,5,6} Output: 2,1,1,0,2 I am getting this error message: Exception in thread “main” java.lang.ArithmeticException: / by zero Answer When you are running the code, this line: Can set count = 0. So when the value at slot 1
Unable to find Dateformat
I know this is a very silly question but I’m unable to find a suitable dateformatter for the given Date: 2020/04/01T20:00-05:00 or 2020/03/05T21:45-07:00. Any sort of help would be highly appreciated. Answer You can’t find one because that is a non-standard format. – is industry standard, using timezone offsets is outdated. Thus, you’d have to make it yourself. But this
How to prevent the outer class method from accessing privately defined methods or fields of a nested class?
I am attempting to prevent the OuterMethod from accessing the privately-defined field InnerField and method InnerMethod. It does not seem to work as what I expect. import static java.lang.System.out; …