将枚举中的所有名称作为 String[] [英] Getting all names in an enum as a String[]

问题描述

将枚举元素的名称作为 String 数组获取的最简单和/或最短的方法是什么?

What's the easiest and/or shortest way possible to get the names of enum elements as an array of Strings?

我的意思是，例如，如果我有以下枚举:

What I mean by this is that if, for example, I had the following enum:

public enum State {
    NEW,
    RUNNABLE,
    BLOCKED,
    WAITING,
    TIMED_WAITING,
    TERMINATED;

    public static String[] names() {
        // ...
    }
}

names() 方法将返回数组 { "NEW", "RUNNABLE", "BLOCKED", "WAITING", "TIMED_WAITING", "TERMINATED" }.

推荐答案

这是任何 enum 类的单行代码:

Here's one-liner for any enum class:

public static String[] getNames(Class<? extends Enum<?>> e) {
    return Arrays.stream(e.getEnumConstants()).map(Enum::name).toArray(String[]::new);
}

Pre Java 8 仍然是单行的，虽然不那么优雅:

Pre Java 8 is still a one-liner, albeit less elegant:

public static String[] getNames(Class<? extends Enum<?>> e) {
    return Arrays.toString(e.getEnumConstants()).replaceAll("^.|.$", "").split(", ");
}

你会这样称呼:

String[] names = getNames(State.class); // any other enum class will work

如果你只是想要一个简单的硬编码枚举类:

If you just want something simple for a hard-coded enum class:

public static String[] names() {
    return Arrays.toString(State.values()).replaceAll("^.|.$", "").split(", ");
}

这篇关于将枚举中的所有名称作为 String[]的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！