4件の投稿件の投稿が「kotlin」タグ付き

val id: Long = Ulid.fast().time // 例：3145144998701、プライマリキーとして使用

data class ShortenRequest(
    val longUrl: String
)

@PostMapping("/api/v1/shorten")
fun shorten(@RequestBody request: ShortenRequest): ResponseEntity<ShortenResponse> {
    val url = urlShortenService.shorten(request.longUrl)
    return ResponseEntity.ok(ShortenResponse(url))
}

private const val BASE62 = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

class Base62Conversion : Conversion {
    override fun encode(input: Long): String {
        val sb = StringBuilder()
        var num = BigInteger.valueOf(input)
        while (num > BigInteger.ZERO) {
            val remainder = num % BigInteger.valueOf(62)
            sb.append(BASE62[remainder.toInt()])
            num /= BigInteger.valueOf(62)
        }
        return sb.reverse().toString()
    }

    override fun decode(input: String): Long {
        var num = BigInteger.ZERO
        for (c in input) {
            num *= BigInteger.valueOf(62)
            num += BigInteger.valueOf(BASE62.indexOf(c).toLong())
        }
        return num.toLong()

    }
}

val pair = "Ferrari" to "Katrina"
println(pair)
// (Ferrari, Katrina)

infix fun Int.times(str: String) = str.repeat(this)
println(2 times "Hello ")
// Hello Hello

infix fun String.onto(other: String) = Pair(this, other)
val myPair = "McLaren" onto "Lucas"
println(myPair)
// (McLaren, Lucas)

class Person(val name: String) {
    val likedPeople = mutableListOf<Person>()

    infix fun likes(other: Person) {
        likedPeople.add(other)
    }
}

fun main() {
    val sophia = Person("Sophia")
    val claudia = Person("Claudia")

    sophia likes claudia // !!
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in 0..fruits.size - 1) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in fruits.size - 1 downTo 0) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in 0..fruits.size - 1 step 2) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in 0 until fruits.size) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in 0 .. fruits.lastIndex) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for (index in fruits.indices) {
        val fruit = fruits[index]
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    for ((index, fruit) in fruits.withIndex()) {
        println("$index: $fruit")
    }
}

val fruits = listOf("Apple", "Banana", "Cherry", "Durian")

fun main() {
    fruits.forEachIndexed { index, fruit ->
        println("$index: $fruit")
    }
}

enum class City(val latitude: Double, val longitude: Double) {
    SEOUL(37.5642135, 127.0016985),
    BUSAN(35.1104, 129.0431);
}

class EllipsoidTest {

    @Test
    internal fun createEllipsoid() {
        val ellipsoid = DefaultEllipsoid.WGS84  // GPSで使用されるWGS84測地系を使用して、地球に最も近い楕円体を作成

        val isSphere = ellipsoid.isSphere  // 球体か楕円体かを判定
        val semiMajorAxis = ellipsoid.semiMajorAxis  // 赤道半径、楕円体の長い半径
        val semiMinorAxis = ellipsoid.semiMinorAxis  // 極半径、楕円体の短い半径
        val eccentricity = ellipsoid.eccentricity  // 離心率、楕円体が球体にどれだけ近いかを示す
        val inverseFlattening = ellipsoid.inverseFlattening  // 逆扁平率の値
        val ivfDefinitive = ellipsoid.isIvfDefinitive // この楕円体に対して逆扁平率が決定的かどうかを示す

        // 大円距離
        val orthodromicDistance = ellipsoid.orthodromicDistance(
            City.SEOUL.longitude,
            City.SEOUL.latitude,
            City.BUSAN.longitude,
            City.BUSAN.latitude
        )

        println("isSphere = $isSphere")
        println("semiMajorAxis = $semiMajorAxis")
        println("semiMinorAxis = $semiMinorAxis")
        println("eccentricity = $eccentricity")
        println("inverseFlattening = $inverseFlattening")
        println("ivfDefinitive = $ivfDefinitive")
        println("orthodromicDistance = $orthodromicDistance")
    }
}