雲原生Java與Golang比較 -lgor

# the service
package main

import (
    "database/sql"
    "fmt"
    "github.com/gin-gonic/gin"
    _ "github.com/go-sql-driver/mysql"
    "net/http"
)

type Fruit struct {
    Id  int `json:"id"`
    Name string `json:"name"`
}

var con *sql.DB

func init(){
  //opening a mysql connection pool with another container 
   db, err := sql.Open("mysql", "root:password@tcp(host.docker.internal:3306)/payments")
   if err != nil {
       panic("failed to open a mysql connection")
   }
   con = db
}

func main() {
    r := gin.Default()
    r.GET("/fruits", fruits)
    r.Run() //server up on 8080
}

// THE REQUEST HANDLER
func fruits(c *gin.Context) {
    fruits := getFruits()
    c.JSON(http.StatusOK, fruits)
}

func getFruits() []Fruit {
    rows, _ := con.Query("SELECT * FROM fruits")
    fruits := []Fruit{}
    for rows.Next() {
        var r Fruit
        rows.Scan(&r.Id, &r.Name)
        fruits = append(fruits, r)
    }
    return fruits
}

package org.acme

import io.vertx.core.json.JsonArray
import io.vertx.core.json.JsonObject
import io.vertx.mutiny.mysqlclient.MySQLPool
import io.vertx.mutiny.sqlclient.Row
import io.vertx.mutiny.sqlclient.RowSet
import java.util.concurrent.CompletionStage
import javax.inject.Inject
import javax.ws.rs.GET
import javax.ws.rs.Path
import javax.ws.rs.Produces
import javax.ws.rs.core.MediaType

@Path("/fruits")
class FruitResource {
    @field:Inject
    lateinit var client: MySQLPool


    @GET
    @Produces(MediaType.APPLICATION_JSON)
    fun listFruits(): CompletionStage<JsonArray> {
        return client.query("SELECT * FROM fruits").execute()
                .map { rows: RowSet<Row> ->
                    rows.fold(JsonArray()) { array, row ->
                        array.add(JsonObject()
                                .put("id", row.getLong("id"))
                                .put("name", row.getString("name")))
                    }
                }.subscribeAsCompletionStage()
    }
}