Java 在给定枚举值的情况下获取枚举名称

Question

How can I get the name of a Java Enum type given its value?

I have the following code which works for a particular Enum type, can I make it more generic ?

public enum Category {

    APPLE("3"), 
    ORANGE("1"), 

    private final String identifier;

    private Category(String identifier) {
        this.identifier = identifier;
    }

    public String toString() {
        return identifier;
    }

    public static String getEnumNameForValue(Object value){
        Category[] values = Category.values();
        String enumValue = null;
        for(Category eachValue : values) {
            enumValue = eachValue.toString();

            if (enumValue.equalsIgnoreCase(value)) {
                return eachValue.name();
            }
        }
        return enumValue;
    }
}

Answer 1

您应该通过调用name()方法来替换getEnumNameForValue 。

Answer 2

Try below code

public enum SalaryHeadMasterEnum {

    BASIC_PAY("basic pay"),
    MEDICAL_ALLOWANCE("Medical Allowance");

    private String name;

    private SalaryHeadMasterEnum(String stringVal) {
        name=stringVal;
    }
    public String toString(){
        return name;
    }

    public static String getEnumByString(String code){
        for(SalaryHeadMasterEnum e : SalaryHeadMasterEnum.values()){
            if(e.name.equals(code)) return e.name();
        }
        return null;
    }
}

Now you can use below code to retrieve the Enum by Value

SalaryHeadMasterEnum.getEnumByString("Basic Pay")

Use Below code to get ENUM as String

SalaryHeadMasterEnum.BASIC_PAY.name()

Use below code to get string Value for enum

SalaryHeadMasterEnum.BASIC_PAY.toString()

Answer 3

Try, the following code..

    @Override
    public String toString() {
    return this.name();
    }

Answer 4

Here is the below code, it will return the Enum name from Enum value.

public enum Test {

    PLUS("Plus One"), MINUS("MinusTwo"), TIMES("MultiplyByFour"), DIVIDE(
            "DivideByZero");
    private String operationName;

    private Test(final String operationName) {
        setOperationName(operationName);
    }

    public String getOperationName() {
        return operationName;
    }

    public void setOperationName(final String operationName) {
        this.operationName = operationName;
    }

    public static Test getOperationName(final String operationName) {

        for (Test oprname : Test.values()) {
            if (operationName.equals(oprname.toString())) {
                return oprname;
            }
        }
        return null;
    }

    @Override
    public String toString() {
        return operationName;
    }
}

public class Main {
    public static void main(String[] args) {

        Test test = Test.getOperationName("Plus One");
        switch (test) {
        case PLUS:
            System.out.println("Plus.....");
            break;
        case MINUS:
            System.out.println("Minus.....");
            break;

        default:
            System.out.println("Nothing..");
            break;
        }
    }
}

Answer 5

In such cases, you can convert the values of enum to a List and stream through it. Something like below examples. I would recommend using filter() .

Using ForEach :

List<Category> category = Arrays.asList(Category.values());
category.stream().forEach(eachCategory -> {
            if(eachCategory.toString().equals("3")){
                String name = eachCategory.name();
            }
        });

Or, using Filter :

When you want to find with code:

List<Category> categoryList = Arrays.asList(Category.values());
Category category = categoryList.stream().filter(eachCategory -> eachCategory.toString().equals("3")).findAny().orElse(null);

System.out.println(category.toString() + " " + category.name());

When you want to find with name:

List<Category> categoryList = Arrays.asList(Category.values());
Category category = categoryList.stream().filter(eachCategory -> eachCategory.name().equals("Apple")).findAny().orElse(null);

System.out.println(category.toString() + " " + category.name());

Hope it helps! I know this is a very old post, but someone can get help.

Answer 6

I believe it's better to provide the required method in the enum itself. This is how I fetch Enum Name for a given value. This works for CONSTANT("value") type of enums.

public enum WalletType {
    UPI("upi-paymode"),
    PAYTM("paytm-paymode"),
    GPAY("google-pay");

    private String walletType;
        WalletType(String walletType) {
            this.walletType = walletType;
        }
    
    public String getWalletType() {
        return walletTypeValue;
    }
    
    public WalletType getByValue(String value) {
        return Arrays.stream(WalletType.values()).filter(wallet -> wallet.getWalletType().equalsIgnoreCase(value)).findFirst().get();
    }
}

eg WalletType.getByValue("google-pay").name() this will give you - GPAY

Answer 7

enum MyEnum {
    ENUM_A("A"),
    ENUM_B("B");

    private String name;
   
    private static final Map<String,MyEnum> unmodifiableMap;

    MyEnum (String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }

    static {
        Map<String,MyEnum> map = new ConcurrentHashMap<String, MyEnum>();
        for (MyEnum instance : MyEnum.values()) {
            map.put(instance.getName().toLowerCase(),instance);
        }
        unmodifiableMap = Collections.unmodifiableMap(map);
    }
    public static MyEnum get (String name) {
        return unmodifiableMap.get(name.toLowerCase());
    }
}

Now you can use below code to retrieve the Enum by Value

MyEnum.get("A");