Java Iterate Enum Using Stream

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In this post, we will learn how to iterate over an Enum using Stream in Java.

Let's use Stream to perform operations on the Enum values.

To create a Stream we have two options, one using Stream.of:

Stream.of(DaysOfWeekEnum.values());

Another, using Arrays.stream:

Arrays.stream(DaysOfWeekEnum.values());

DaysOfWeekEnum.java

Let's first create an Enum called DaysOfWeekEnum. Note that we are using Stream.of() method.

import java.util.stream.Stream;

enum DaysOfWeekEnum {
    SUNDAY("off"),
        MONDAY("working"),
        TUESDAY("working"),
        WEDNESDAY("working"),
        THURSDAY("working"),
        FRIDAY("working"),
        SATURDAY("off");

    private String typeOfDay;

    DaysOfWeekEnum(String typeOfDay) {
        this.typeOfDay = typeOfDay;
    }

    public String getTypeOfDay() {
        return typeOfDay;
    }

    public void setTypeOfDay(String typeOfDay) {
        this.typeOfDay = typeOfDay;
    }

    public static Stream < DaysOfWeekEnum > stream() {
        return Stream.of(DaysOfWeekEnum.values());
    }
}

EnumIterationExample.java

Let's write an example in order to print all the Enum values using the forEach() method:

public class EnumIterationExample {
    public static void main(String[] args) {
         System.out.println("Enum iteration using Stream:");
         DaysOfWeekEnum.stream().forEach(System.out::println);
    }
}

Output

Enum iteration using Stream:
SUNDAY
MONDAY
TUESDAY
WEDNESDAY
THURSDAY
FRIDAY
SATURDAY

Complete Example

import java.util.stream.Stream;

public class EnumIterationExample {
    public static void main(String[] args) {
        System.out.println("Enum iteration using Stream:");
        DaysOfWeekEnum.stream().forEach(System.out::println);
    }
}


enum DaysOfWeekEnum {
    SUNDAY("off"),
        MONDAY("working"),
        TUESDAY("working"),
        WEDNESDAY("working"),
        THURSDAY("working"),
        FRIDAY("working"),
        SATURDAY("off");

    private String typeOfDay;

    DaysOfWeekEnum(String typeOfDay) {
        this.typeOfDay = typeOfDay;
    }

    public String getTypeOfDay() {
        return typeOfDay;
    }

    public void setTypeOfDay(String typeOfDay) {
        this.typeOfDay = typeOfDay;
    }

    public static Stream < DaysOfWeekEnum > stream() {
        return Stream.of(DaysOfWeekEnum.values());
    }
}

Output:

Enum iteration using Stream:
SUNDAY
MONDAY
TUESDAY
WEDNESDAY
THURSDAY
FRIDAY
SATURDAY