How to store value of enum in arraylist?

Question

I have an enum like this:

public enum SomeEnum 
{
    ENUM_VALUE1("Some value1"),
    ENUM_VALUE2("Some value2"),
    ENUM_VALUE3("Some value3");
}

I need to store values of enum Some value1 , Some value2 and Some value3 in an ArrayList .

I can get all values in an array using SomeEnum.values() and iterate over that array and store the value in an ArrayList like this:

SomeEnum values[] = SomeEnum.values();
ArrayList<SomeEnum> someEnumArrayList = new ArrayList<SomeEnum>();
for(SomeEnum value:values) 
{
    someEnumArrayList.add(value.getValue());
}

Is there any other method like values() that returns array of Some value1 , Some value2 and Some value3 ?

Answer 1

You could build that list inside the enum itself like this:

public enum SomeEnum {

    ENUM_VALUE1("Some value1"),
    ENUM_VALUE2("Some value2"),
    ENUM_VALUE3("Some value3");

    private static final List<String> VALUES;

    private final String value;

    static {
        VALUES = new ArrayList<>();
        for (SomeEnum someEnum : SomeEnum.values()) {
            VALUES.add(someEnum.value);
        }
    }

    private SomeEnum(String value) {
        this.value = value;
    }

    public static List<String> getValues() {
        return Collections.unmodifiableList(VALUES);
    }

}

Then you can access this list with:

List<String> values = SomeEnum.getValues();

Answer 2

If you're using Java 8 and cannot change the enum:

List<String> list = Stream.of(SomeEnum.values())
                          .map(SomeEnum::getValue)
                          .collect(Collectors.toList());

Answer 3

你可以简单地从数组创建列表，如下所示：

List<String> list = Arrays.asList(SomeEnum.values());