디자인 패턴의 아름다움 스터디 코드

IdGenerator.kt

import java.net.InetAddress
import java.util.Random

fun random(): String {
    val randomChars = CharArray(8)

    var count = 0
    val random = Random()
    while (count < 8) {
        val randomAscii = random.nextInt(122)
        when (randomAscii) {
            in 48..57 -> {
                randomChars[count] =
                    ('0'.code + (randomAscii - 48)).toChar()
                count++
            }

            in 65..90 -> {
                randomChars[count] =
                    ('A'.code + (randomAscii - 65)).toChar()
                count++
            }

            in 97..122 -> {
                randomChars[count] =
                    ('a'.code + (randomAscii - 97)).toChar()
                count++
            }

            else -> {
                continue
            }
        }::class
    }

    return randomChars.toString()
}

class GenerateEffect(
    val hostName: String,
    val timestamp: Long,
    val seed: String,
)

var defaultEffect = GenerateEffect(
    try {
        InetAddress.getLocalHost().hostName.split(
            Regex("\\.")
        ).last()
    } catch (e: Throwable) {
        random()
    },
    System.currentTimeMillis(),
    random()
)

object IdGenerator {
    fun generate(
        effect: GenerateEffect = defaultEffect
    ): String {
        return String.format(
            "%s-%d-%s", effect.hostName,
            effect.timestamp,
            effect.seed
        )
    }
}