How can I create a Stream that creates a number of items based on a custom generate() method? The question is different from the one referred to. The final result is a Stream, so I could (simplistically) use a “.forach( System.out::println)”. An example would be: Stream.generate( myGenerateMethod)…
Tag: java-8
installing tomcat 9 on WSL
After installing tomcat 9 on WSL, it isn’t recognized by system. Since systemctl command doesn’t work on WSL, I used below command: returning I followed 2 ways to install, but the same problem occurred. References are: https://www.digitalocean.com/community/tutorials/install-tomcat-9-ubuntu-1804 h…
How to collect a map of a pojo id to a set of a property of a collection on the pojo
I’m trying to use streams to get a map of a pojo to a Set of items exposed by a property on the pojo. I realise that isn’t clear so I’ll show how I’ve done it without streams. I have and enum of …
Exception propagation in CompletableFuture (java)
How can I propagate exception encountered in the following code inside CompletableFuture.runAsync to my main thread? I want to catch the IllegalStateException in my main thread. Answer One option would be to create a Collection of Throwable objects and when the CompletableFuture completes you can add the exce…
How do you call a method from within a Collector in Java 8 Streaming?
I have a bit of code that is working functionally as I want it to: private Map localMethod(List branchList) { Map
How to search for a string in a pdf document [closed]
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations. Closed 2 years ago. Improve this ques…
For loop inside for loops code optimisation
I have an loop inside loop to remove the elements from the seconde loop, and what is present in the list has to perform certain actions. I wish to optimize the iteration and comparisons, can it be done? How do I optimize my logic shown below to avoid so many lines of code Answer After minLenghtOfEntities += f…
Possible to remove Title bar from JFileChooser?
I am trying to display a simple JFileChooser that has no Titlebar. Below is the example code: So essentially I want the Border I set to be the top level Title bar. Example image: So far I have had zero luck achieving this, nor found any others looking for a similar appearance. Appreciate the help! Cheers Answ…
Keycloak java.lang.NoClassDefFoundError: java/security/acl/Group using Springboot
So we are building a Springboot back-end with Keycloak integration. But we get the following error when running the back-end on a docker swarm service: I tried it with JDK 8 and JDK 11 since the following post implies that the wrong JDK can cause a problem: Stackoverflow post. It still gives this error. The f…
Java 8 Remove 1 List from Other
I have two list of different Objects. I want to remove the list of School objects from List of World objects based on schoolName and location. I cannot use equals and hashCode methods on those two fields as it is creating some other problem. Please help me how it can be done using streams. Answer You can use …