downloader.go

package main

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
)

const urlTemplate = "http://www.apifito.net/zivica-otzyvy.php?id=%v"
const fileNameTemplate = "page_%v.html"

type task struct {
	Url      string
	FileName string
}

func downloader(taskChan <-chan task) {
	for {
		myTask := <-taskChan

		resp, err := http.Get(myTask.Url)
		if err != nil {
			continue
		}
		defer resp.Body.Close()

		file, err := os.Create(myTask.FileName)
		if err != nil {
			panic(err)
		}
		defer file.Close()

		n, err := io.Copy(file, resp.Body)
		if err != nil {
			panic(err)
		}
		log.Printf("Copied %v bytes from %v to %v\n",
			n,
			myTask.Url,
			myTask.FileName)
	}
}

func main() {
	const numberOfdownloaders = 10

	taskChan := make(chan task)

	for i := 0; i < numberOfdownloaders; i++ {
		go downloader(taskChan)
	}

	for i := 1; i <= 530; i++ {
		myTask := task{fmt.Sprintf(urlTemplate, i),
			fmt.Sprintf(fileNameTemplate, i)}
		taskChan <- myTask
	}
}