go-爬蟲-百度貼吧（併發版）

爬取百度貼吧的網頁

非併發版

package main

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

func HttpGet(url string) (result string, err error) {
    //  var result string
    resp, err1 := http.Get(url)
    if err1 != nil {
        err = err1
        return
    }
    defer resp.Body.Close()

    buf := make([]byte, 4096)
    for {
        n, err2 := resp.Body.Read(buf)
        if n == 0 {
            fmt.Println("讀取網頁完成")
            break
        }
        if err2 != nil && err2 != io.EOF {
            err = err2
            return
        }
        result += string(buf[:n])
    }
    return
}

func working(start, end int) {
    fmt.Printf("正在爬取第%d到第%d頁", start, end)
    //爬取每個網頁
    for i := start; i <= end; i++ {
        url := "https://tieba.baidu.com/f?kw=vue&ie=utf-8&pn=" + strconv.Itoa((i-1)*50)
        result, err := HttpGet(url)
        if err != nil {
            fmt.Println("httpGet err", err)
            continue
        }
        //      fmt.Println("result", result)
        f, err := os.Create("第" + strconv.Itoa(i) + "頁" + ".html")
        if err != nil {
            fmt.Println("HttpGet err", err)
            continue
        }
        f.WriteString(result)
        f.Close()
    }
}

func main() {
    var start, end int
    fmt.Print("請輸入起始頁。。。")
    fmt.Scan(&start)
    fmt.Print("請輸入終止頁。。。")
    fmt.Scan(&end)

    working(start, end)
}

併發版

這個只是在上面的基礎上加了管道和開了協程

package main

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

func HttpGet(url string) (result string, err error) {
    //  var result string
    resp, err1 := http.Get(url)
    if err1 != nil {
        err = err1
        return
    }
    defer resp.Body.Close()

    buf := make([]byte, 4096)
    for {
        n, err2 := resp.Body.Read(buf)
        if n == 0 {
            fmt.Println("讀取網頁完成\n")
            break
        }
        if err2 != nil && err2 != io.EOF {
            err = err2
            return
        }
        result += string(buf[:n])
    }
    return
}

func SpiderPage(index int, page chan int) {
    fmt.Printf("正在爬取第%d到頁\n", index)
    //爬取每個網頁
    //  for i := start; i <= end; i++ {
    url := "https://tieba.baidu.com/f?kw=vue&ie=utf-8&pn=" + strconv.Itoa((index-1)*50)
    result, err := HttpGet(url)
    if err != nil {
        fmt.Println("httpGet err", err)
        return
    }
    //      fmt.Println("result", result)
    f, err := os.Create("第" + strconv.Itoa(index) + "頁" + ".html")
    if err != nil {
        fmt.Println("HttpGet err", err)
        return
    }
    f.WriteString(result)
    f.Close()
    //  }

    page <- index
}

func working2(start, end int) {
    fmt.Printf("正在爬取第%d頁到%d頁\n", start, end)

    page := make(chan int)

    for i := start; i <= end; i++ {
        go SpiderPage(i, page)
    }

    for i := start; i <= end; i++ {
        fmt.Printf("第%d個頁面爬取完成\n", <-page)
    }
}

func main() {
    var start, end int
    fmt.Print("請輸入起始頁。。。")
    fmt.Scan(&start)
    fmt.Print("請輸入終止頁。。。")
    fmt.Scan(&end)

    working2(start, end)
}