Is there a way to run getUsers() asynchronously only from main() in Java 8? Running getUsers() on the main thread would take 300 seconds. I wish to make it in less than 180 seconds with 4 cores. Without modifying getUsers() (the objective), running the following is still taking 300 seconds: Answer You can div…
Tag: list
Adding an element to the end of a List in java
I have this array that I converted into a list: How would I go about adding a character to the end of the list since there isn’t a specific add function for Lists? Edit: Both my classes and code Answer you have an array of String and convert it to List of String so you cannot add a char to
Create and find highest value in subarraylist
I have an Arraylist of the Cells from an Excel sheet. I want to create subarraylists of size 50 from the Arraylist of Cells I actually have, beginning from the index of 1590 and ending with size()-700. I want to get the highest number from every subarraylist and put it in the new Arraylist. in the new Arrayli…
how to add synchronization in following lambda exp?
Can synchronized blocks be used for some of the code blocks written in lambda expression . With respect to the following code snippet : Answer It is possible to use synchronized blocks inside a Java Lambda Expression and inside anonymous classes. Note: You have forgotten to add code snippet as no code snippet…
How to map Iterable to its DTO?
I have the following repository: PermissionRepository: In my service, I am trying to map Permission entity to PermissionDTO, but as findAll() method returns Iterable<T> (Iterable<T> findAll();), I cannot convert as shown below as I generally use for List<T>. It throws “Cannot resolve m…
Reverse subset of ArrayList using multidimensional ArrayList in Java
I am trying to reverse a sublist in a List using the indices provided in a multidimensional List. I don’t have much experience using multidimensional lists/arrays. I don’t understand why this doesn’t work. The output of this code using [[0,1], [1, 3]] as the indecies is: but it should be: Ca…
How do I insert an Item at a certain Index in a Linked List?
I am working on a project for my Data Structures class that asks me to write a class to implement a linked list of ints. Use an inner class for the Node. Include the methods below. Write a tester to enable you to test all of the methods with whatever data you want in any order. I have to create
how do I split array element into more element [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 last year. Improve this question this is…
List of int array in Java
How do I print the contents of a List that contains a primitive type int object in it? Prefer answers to print this in one line. This is the code I have. This will give me [0,1] but I am looking for {[0,1],[2,3]} Answer The following one-liner can meet your requirement: It uses the positive lookbehind and pos…
How to filter an array of objects by month and year – Java
I’m new at Java and I have a question. I have this array of objects: That contains this: I would like to know how can I filter this array by month and year. A first example would be filter the array by month 10 and year 2021. Any suggestion ? Answer You can use the Stream API to do it