java-8 Questions
7
Solved
I want to something which is similar to the Scala grouped function. Basically, pick 2 elements at a time and process them. Here is a reference for the same:
Split list into multiple lists with fixe...
Feint asked 29/1, 2015 at 9:11
7
Solved
I am trying to learn java - stream. I am able to do simple iteration / filter / map / collection etc.
When I was kind of trying to collect every 3 elements and print as shown here in this example,...
Frequentation asked 27/3, 2017 at 22:45
7
Solved
While hunting through some code I came across the arrow operator, what exactly does it do? I thought Java did not have an arrow operator.
return (Collection<Car>) CollectionUtils.select(list...
2
Solved
Did like below,
LocalDateTime currentUTCTime = LocalDateTime.now(ZoneId.of("UTC"));
String reqPattern = currentUTCTime.format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss:SSS"));
System.out.pr...
2
Solved
I'm playing around with the new java.time package in Java 8. I have a legacy database that gives me java.util.Date, which I convert to Instant.
What I am trying to do is add a period of time that ...
28
Solved
Is there a concise way to iterate over a stream whilst having access to the index in the stream?
String[] names = {"Sam","Pamela", "Dave", "Pascal", "Erik"};
List<String> nameList;
Stream&l...
Animalcule asked 31/8, 2013 at 19:31
2
I've got a Java8 application running on RHEL 6.10. This application registers a shutdown handler via the usual method:
Thread shutdownThread = new Thread(()=>{
Logger.info("Got shutdown signal...
4
Solved
Initially code was :
if(!Objects.equals(src.getApplicationItemCost(), dest.getApplicationItemCost())){
log.info("Difference")
}
Output:
getApplicationItemCost: src:0.0| dest:0
Difference
...
Moses asked 12/2, 2020 at 6:47
6
IntelliJ keeps proposing me to replace my lambda expressions with method references.
Is there any objective difference between both of them?
Omega asked 30/6, 2014 at 10:14
2
Solved
TL;DR: GC is eating my active bindings.
I have an app that was developed and successfully deployed using JavaFX 2.2 on Java 7.
When I upgraded/transitioned to JavaFX 8.0 (and Java 8), certain featu...
5
I generate UUIDs, and valid them against a Regex in my code; I just ran into problems that confused me
Here is the code that generates UUIDs (in a mongodb context)
import java.util.UUID;
... ......
20
While running mvn install in my project, I end up with this error. While a lot of answers and resources point out errors in / vs \, I want to mention that I have no local changes and this repo just...
7
I have a list of objects say car. I want to filter this list based on some parameter using Java 8. But if the parameter is null, it throws NullPointerException. How to filter out null values?
Curr...
Pyle asked 1/10, 2015 at 9:36
6
Solved
When I try to run Zeppelin by either
bin/zeppelin.sh
or
bin/zeppelin-deamon.sh start
I was getting the following error message.
Unrecognized VM option 'MaxPermSize=512m'
Error: Could not cre...
Islington asked 4/11, 2017 at 15:38
12
Solved
I am looking for a concise way to convert an Iterator to a Stream or more specifically to "view" the iterator as a stream.
For performance reason, I would like to avoid a copy of the iterator in a...
21
I am trying to list out duplicate elements in an integer list using Streams of JDK 8. For example:
// Duplicates are {1, 4}
List<Integer> numbers = Arrays.asList(new Integer[]{1,2,1,3,4,4});
...
Onofredo asked 28/12, 2014 at 14:19
10
Solved
Since Java8 has been recently released and its brand new lambda expressions looks to be really cool, I was wondering if this means the demise of the Anonymous classes that we were so used to.
I've...
Stefan asked 25/3, 2014 at 14:41
4
Solved
I need to translate between IANA timezone & windows timezone & vice-versa. There is another question reported: How to translate between Windows and IANA time zones?
It specifies that Noda ...
13
Solved
How to count the frequency of words of List in Java 8?
List <String> wordsList = Lists.newArrayList("hello", "bye", "ciao", "bye", "ciao");
The result must be:
{ciao=2, hello=1, bye=2}
...
Teodoor asked 18/3, 2015 at 12:43
6
Solved
How can I split odd and even numbers and sum both in a collection using stream methods of Java 8?
public class SplitAndSumOddEven {
public static void main(String[] args) {
// Read the input
t...
Cleancut asked 22/1, 2016 at 5:10
6
Solved
While I was in a dockerization project in my current job, I got this doubt: Which Java can I use?
This doubt is due to :
So after some researches I got these conclusions:
Since the Java 8 update ...
4
Solved
I am writing an app that needs to be quite accurate in dates and I wonder how can I compare LocalDate instances.. for now I was using something like:
LocalDate localdate1 = LocalDate().now();
Loca...
15
My exact scenario is inserting data to database in batches, so I want to accumulate DOM objects then every 1000, flush them.
I implemented it by putting code in the accumulator to detect fullness ...
Edam asked 20/12, 2014 at 19:33
7
Solved
In java 8, what's the best way to check if a List contains any duplicate?
My idea was something like:
list.size() != list.stream().distinct().count()
Is it the best way?
Stonemason asked 5/5, 2015 at 12:50
5
Solved
I am currently replacing all my standard POJO's to use Lombok for all the boilerplate code. I find myself keeping getters for lists because I want to return an empty list if the list has not been i...
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