KtorApp.kt

package main

import com.zaxxer.hikari.HikariDataSource
import org.apache.ibatis.annotations.Insert
import org.apache.ibatis.annotations.Select
import org.apache.ibatis.mapping.Environment
import org.apache.ibatis.session.Configuration
import org.apache.ibatis.session.SqlSession
import org.apache.ibatis.session.SqlSessionFactory
import org.apache.ibatis.session.SqlSessionFactoryBuilder
import org.apache.ibatis.transaction.jdbc.JdbcTransactionFactory
import org.jetbrains.ktor.application.call
import org.jetbrains.ktor.application.install
import org.jetbrains.ktor.host.embeddedServer
import org.jetbrains.ktor.netty.Netty
import org.jetbrains.ktor.response.respondText
import org.jetbrains.ktor.routing.Routing
import org.jetbrains.ktor.routing.get

/**
 Ktor（corutine）使ったマイクロWebフレームワークで試す
 MyBatisでDBアクセス、トランザクション管理
 */
fun main(args: Array<String>): Unit {

    val sessionFactory: SqlSessionFactory = createSessionFactory()

    embeddedServer(Netty, 8080) {
        install(Routing) {
            get("/") {
                withSession(sessionFactory.openSession()) {
                    val mapper = getMapper(PersonMapper::class.java)
                    val str =dao.selectAll()
                            .map{it.toString()}
                            .reduceRight{first:String,second:String -> first +":" + second}
                 
                    call.respondText(str)
                }
            }

            get("/insert") {
                withSession(sessionFactory.openSession()) {
                    val mapper = getMapper(PersonMapper::class.java)
                    val name  = call.request.queryParameters["name"]
                    val id  = call.request.queryParameters["id"]
                    if(null != id && null != name){
                        val p =Person(id.toInt(), name)
                        dao.insert(p)
                        call.respondText("OK!"+p)
                    }else{
                        call.respondText("NG!")

                    }
                }
            }
        }
    }.start(wait = true)
}

/**
 corutinから呼べるようにsuspendファンクションとして定義
 パフォーマンス的にどこまでcorutineのメリット生かせるのかは？
 */
suspend fun withSession(session: SqlSession, block: suspend SqlSession.() -> Unit) {
    session.use {
        try {
            block.invoke(session)
            session.commit()
        }catch (e:Exception){
            session.rollback()
            throw e
        }
    }
}

data class Person(val id: Int, val name: String)
interface PersonMapper {

    @Select("""
        SELECT *
        FROM person
            """)
    fun selectAll(): List<Person>

    @Insert("""
        INSERT into person
        VALUES(#{id},#{name})
            """)
    fun insert(person: Person): Int
}

fun createSessionFactory(): SqlSessionFactory {
    val dataSource = HikariDataSource()
    dataSource.jdbcUrl = "jdbc:h2:mem:hello"
    dataSource.username = "user"
    dataSource.password = "pass"

    val transactionFactory = JdbcTransactionFactory()
    val environment = Environment("development", transactionFactory, dataSource)
    val configuration = Configuration(environment)

    dataSource.connection.use { connection ->
        val st = connection.createStatement()
        st.execute("create table person (id int primary key, name varchar(100))")
        st.execute("insert into person(id, name) values (1, 'Boy')")
    }
    configuration.addMapper(PersonMapper::class.java)
    return SqlSessionFactoryBuilder().build(configuration)
}