Question

假设我有这个枚举：

public enum MyEnum {
    AUSTRALIA_SYDNEY ("Australia/Sydney"),
    AUSTRALIA_ADELAIDE ("Australia/Adelaide"),

    private String name

    private Timezone(String name){
        this.name = name
    }

    public String value() {
        name
    }

    String toString() {
        name
    }
}

有没有办法让我使用其值/名称获取枚举？现在，我正在尝试这样做，但它不起作用：

MyEnum.valueOf("Australia/Sydney")

我从数据库中得到的是一个字符串（在这种情况下：“澳大利亚/悉尼”），而不是价值，不幸的是，我不能只改变它返回的类型，因为它是旧的系统，我只是连接到这个由多个应用程序共享的数据库。无论如何围绕这个？

Answer 1

将以下内容添加到枚举中：

static MyEnum valueOfName( String name ) {
    values().find { it.name == name }
}

然后，您可以致电：

MyEnum.valueOfName( "Australia/Adelaide" )

Answer 2

为了完整性添加到以前的答案，这里有其他选项，结合了Haki先生引用的帖子。这个答案取自Amit Jain的博客文章： http://www.intelligrape.com/blog/groovy-few-ways-to-convert-string-into-enum/

enum AccountType {
     CHECKING,
     SAVING
}

assert AccountType.CHECKING == "CHECKING" as AccountType

assert AccountType.CHECKING == AccountType.valueOf("CHECKING")
def className = AccountType.class
assert AccountType.CHECKING == Enum.valueOf(className, "CHECKING")

assert AccountType.CHECKING == AccountType["CHECKING"]
String type = "CHECKING"
assert AccountType.CHECKING == AccountType[type]

Answer 3

参考博客http://mrhaki.blogspot.ae/2010/12/groovy-goodness-transform-string-into.html，有多种方法可以将String转换为Enum。

enum Compass {
    NORTH, EAST, SOUTH, WEST
}

// Coersion with as keyword.
def north = 'NORTH' as Compass
assert north == Compass.NORTH

// Coersion by type.
Compass south = 'south'.toUpperCase()
assert south == Compass.SOUTH

def result = ['EA', 'WE'].collect {
    // Coersion of GString to Enum.
    "${it}ST" as Compass
}
assert result[0] == Compass.EAST
assert result[1] == Compass.WEST

Answer 4

assert AccountType.CHECKING == "CHECKING" as AccountType

Grails字符串枚举？

4 个答案: