I have a stream from elements of a class x. One of the arributes (t) of the class x is from type LocalDateTime and I need to group the elements by hours. I tried something like this: But this syntax doesn´t work, any other idea of what i might be able to do? Answer The attempt is actually pretty close.
Tag: java
Java aggregate same objects into one
I’m quite new into programming and got a tricky question. I got an object which has multiple parameters: Every object always has non-null number attribute as well as one of three values-field. So for example, if valueOne is not null, the other two value fields valueTwo and valueThree would be null. So h…
Need help on printing an Array of ArrayLists (of different sizes)
I’m making my own solitaire program I can run on my computer (for leisure and practice) and I am trying to display my ‘ArrayList<Card>[] playspace’ like it shows in Solitaire. More specifically I’m trying to display the card order downward instead of to the right side like it cur…
Why does the Recycleview work differently when I start it or when I go back to it from an other activity?
I try to create a Shopping/ToDoList application where the items are contained in SharedPreferences. When I start the application, and I choose what I want to execute, Shopping list part or ToDoList part, then the java code fetches the existing data from the SharedPreferences and give to the RecycleView to cre…
Amazon.in site language setting radio button handling in selenium
I am new to selenium automation and while learning radio button handling in selenium, I tried to automate language setting in amazon.in page. I am unable to select the radio button listed in the page. site: https://www.amazon.in/customer-preferences/edit?ie=UTF8&preferencesReturnUrl=%2F&ref_=topnav_la…
Can I add an image knowing its URI from the phone to the r.drawable folder in Android Studio to use it in a ListView?
I have got the URI of an image from an Input Image Activity. I have passed this URI to the Main Activity using .putExtra. Now I have the URI of the image in the Main Activity and I want to save the image somehow in r.drawable folder or to convert it to a picture which I can save to r.drawable.
Method chaining between child and parent classes
So imagine we have the following. I’m trying to do this, What are the possible ways to achieve this? And what’s the best one (convention)? Answer I’ve seen at least two approaches. Make Animal generic, and use the generic type as return type: Override the method like Alex R said in his comme…
Postman with “body” (json) and files (multipart) together in 1 restful request
How do I use Postman to send queries with body (in json format) and files (in multipart) format at the same time? I think I should use Postman->Body->Raw although I can’t find an example on the Web. Anyone can kindly teach me? Thank you! Answer In postman, set method type to POST. Then select Body…
Divide by zero, can’t find the problem in this program which runs Euclid’s algorithm to find the greatest common divisor
I followed the steps of Euclid’s algorithm but I was stunned when a divide by zero problem appeared. I don’t know how it can happen. Answer The problem is with the below two lines. First statement will make a[0] as 0 since c is 0. Next statement will be 1/0.
Code intellisense is not working to JavaFX library in VSCode
Code intellisense is only not working for JavaFX in VSCode. I developed a JavaFX application once, and intellisense was working then, but it’s not working now. build.gradle I installed Java pack Extension and gradle extension. Answer It was solved. There is a solution below. Installing eclipse plugin an…