枚举 valuesOf 转换字符串为对象状态实战

public enum OrderStatus {
    PENDING, PROCESSING, SHIPPED, DELIVERED
}
// ✅ 成功
OrderStatus status = Enum.valueOf(OrderStatus.class, "PENDING");

// ❌ 抛 IllegalArgumentException：No enum constant OrderStatus.pending
Enum.valueOf(OrderStatus.class, "pending");

// ❌ 抛 IllegalArgumentException：No enum constant OrderStatus.PENDING 
Enum.valueOf(OrderStatus.class, "PENDING "); // 末尾有空格

public class EnumUtils {
    public static <T extends Enum<T>> T parseIgnoreCase(Class<T> enumType, String value, T defaultValue) {
        if (value == null || value.trim().isEmpty()) {
            return defaultValue;
        }
        String trimmed = value.trim();
        try {
            return Enum.valueOf(enumType, trimmed.toUpperCase());
        } catch (IllegalArgumentException e) {
            return defaultValue;
        }
    }
}

// 使用
OrderStatus status = EnumUtils.parseIgnoreCase(OrderStatus.class, "pending", OrderStatus.PENDING);

public enum OrderStatus {
    PENDING("pending", "待处理"),
    PROCESSING("processing", "处理中"),
    SHIPPED("shipped", "已发货"),
    DELIVERED("delivered", "已送达");

    private final Set<String> aliases;

    OrderStatus(String... aliases) {
        this.aliases = Arrays.stream(aliases)
                .map(String::toLowerCase)
                .collect(Collectors.toSet());
    }

    public static Optional<OrderStatus> from(String input) {
        if (input == null) return Optional.empty();
        String key = input.trim().toLowerCase();
        for (OrderStatus s : values()) {
            if (s.aliases.contains(key)) {
                return Optional.of(s);
            }
        }
        return Optional.empty();
    }
}

// 使用
OrderStatus status = OrderStatus.from("待处理").orElse(OrderStatus.PENDING);