go单任务版爬虫

go单任务版爬虫(爬取珍爱网)

爬虫总体算法

单任务版爬虫架构

任务

获取并打印所在城市第一页用户的详细信息

代码实现

/crawler/main.go

package main

import (
    "crawler/engine"
    "crawler/zhenai/parser"
)

func main() {
    engine.Run(engine.Request{
        Url:"http://www.zhenai.com/zhenghun",
        ParseFunc: parser.ParseCityList,
    })
}

/crawler/engine/engine.go

package engine

import (
    "crawler/fetcher"
    "log"
)
// seeds:url种子
func Run(seeds ...Request)  {
    var requests []Request
    for _, r := range seeds {
        requests = append(requests, r)
    }
    for len(requests) > 0 {
        r := requests[0]
        requests = requests[1:]
        log.Printf("Fetching: %s", r.Url)
        body, err := fetcher.Fetch(r.Url)
        if err != nil {
            log.Printf("Fetcher: error" + "fetching url %s: %v", r.Url, err)
            continue
        }
        parseResult := r.ParseFunc(body)
        requests = append(requests, parseResult.Requests...)
        for _, item := range parseResult.Items{
            log.Printf("Got item %v", item)
        }
    }
}

/crawler/engine/types.go

package engine

type Request struct {
    Url string
    ParseFunc func([]byte) ParseResult
}
type ParseResult struct {
    Requests []Request
    Items []interface{}
}
func NilParser([]byte) ParseResult{
    return ParseResult{}
}

/crawler/fetcher/fetcher.go

package fetcher

import (
    "bufio"
    "fmt"
    "golang.org/x/net/html/charset"
    "golang.org/x/text/encoding"
    "golang.org/x/text/encoding/unicode"
    "golang.org/x/text/transform"
    "io/ioutil"
    "log"
    "net/http"
)

//获取内容
func Fetch(url string) ([]byte, error)  {
    client := &http.Client{}
    req, err := http.NewRequest("GET", url, nil)
    if err != nil {
        return nil, err
    }
    req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36")
    resp, err := client.Do(req)
    if err != nil {
        return nil, err
    }
    defer resp.Body.Close()
    if resp.StatusCode != http.StatusOK {
        return nil, fmt.Errorf("Wrong status code: %d", resp.StatusCode)
    }
    bodyReader := bufio.NewReader(resp.Body)
    e := determineEncoding(bodyReader)
    utf8Reader := transform.NewReader(bodyReader, e.NewDecoder())
    return ioutil.ReadAll(utf8Reader)
}
//转换编码
func determineEncoding(r *bufio.Reader) encoding.Encoding  {
    bytes, err := r.Peek(1024)
    if err != nil {
        log.Printf("Fetcher error: %v", err)
        return unicode.UTF8
    }
    e, _, _ := charset.DetermineEncoding(bytes, "")
    return e
}

/crawler/zhenai/parser/citylist.go

package parser

import (
    "crawler/engine"
    "regexp"
)
//解析UTF8文本,获取城市url列表
const cityListRe  = `<a href="(http://www.zhenai.com/zhenghun/[0-9a-z]+)" [^>]*>([^<]+)</a>`
func ParseCityList(contents []byte) engine.ParseResult {
    re := regexp.MustCompile(cityListRe)
    matches := re.FindAllSubmatch(contents, -1)
    result := engine.ParseResult{}
    limit := 5 //设置限制,便于测试
    for _, m := range matches {
        result.Items = append(result.Items, "City: "+string(m[2]))
        result.Requests = append(result.Requests, engine.Request{
            Url:       string(m[1]),
            ParseFunc: ParseCity,
        })
        limit--
        if limit == 0 {
            break
        }
    }
    return result
}

/crawler/zhenai/parser/city.go

package parser

import (
    "crawler/engine"
    "regexp"
)
//解析单个城市,获取用户
const cityRe = `<a href="(http://album.zhenai.com/u/[0-9]+)" [^>]*>([^<]+)</a>`
func ParseCity(contents []byte) engine.ParseResult {
    re := regexp.MustCompile(cityRe)
    matches := re.FindAllSubmatch(contents, -1)
    result := engine.ParseResult{}
    for _, m := range matches {
        name := string(m[2])
        result.Items = append(result.Items, "User: "+name)
        result.Requests = append(result.Requests, engine.Request{
            Url:       string(m[1]),
            ParseFunc: func(c []byte) engine.ParseResult {
                return ParseProfile(c, "name:"+name)
            },
        })
    }
    return result
}

/crawler/zhenai/parser/profile.go

package parser

import (
    "crawler/engine"
    "crawler/model"
    "regexp"
)
//获取用户信息
const all = `<div class="m-btn purple" data-v-8b1eac0c>([^<]+)</div>`
func ParseProfile(contents []byte, name string) engine.ParseResult {
    profile := model.Profile{}
    profile.User = append(profile.User, name)
    re := regexp.MustCompile(all)
    match := re.FindAllSubmatch(contents,-1)
    if match != nil {
        for _, m := range match {
            profile.User = append(profile.User, string(m[1]))
        }
    }

    result := engine.ParseResult{
        Items: []interface{}{profile},
    }
    return result
}

/crawler/model/profile.go

package model
type Profile struct {
    User []string
}

任务结果

完整代码

https://gitee.com/FenYiYuan/golang-oncrawler.git