JCH
Java Community | Help. Code. Learn.•3y ago
direct_x_34

Java 8 Stream Calculating the total value by month

Here is my Java 8 steam issue which I tried to mention. I store the values as Map<String(pId),List (Person Object)> Here is the list 
ID,Info,Date (All values are stored in Person object defined in the List)

per1, JOIN,  10-01-2022
per2, JOIN, 10-01-2022
per3, EXIT, 10-01-2022 
per3 EXIT, 10-02-2022
per4, JOIN, 10-03-2022`
ID,Info,Date (All values are stored in Person object defined in the List)

per1, JOIN,  10-01-2022
per2, JOIN, 10-01-2022
per3, EXIT, 10-01-2022 
per3 EXIT, 10-02-2022
per4, JOIN, 10-03-2022`
What I want to do is to get this result. 
Month  Info Total Number
1            JOIN       2
1            EXIT       1
2           EXIT       1
3          JOIN       1
Month  Info Total Number
1            JOIN       2
1            EXIT       1
2           EXIT       1
3          JOIN       1
Here is my dto shown below. 
public class dto {
    private int month;
    private State info;  // State -> enum
    private int totalEmployees;  
}
public class dto {
    private int month;
    private State info;  // State -> enum
    private int totalEmployees;  
}
Here is the code snippet but I cannot complete it. 
List<dto > result = persons.values().stream()
                .flatMap(List::stream)
                ...
List<dto > result = persons.values().stream()
                .flatMap(List::stream)
                ...
Can you help me?
1 Reply
JavaBot
JavaBot•3y ago
Hey, @direct_x_34! Please remember to /close this post once your question has been answered! 💤 Post marked as dormant
This post has been inactive for over 300 minutes, thus, it has been archived. If your question was not answered yet, feel free to re-open this post or create a new one.

Did you find this page helpful?