Golang开发：构建支持并发的网络爬虫

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

type Spider struct {

    baseURL  string

    maxDepth int

    queue    chan string

    visited  map[string]bool

}

func NewSpider(baseURL string, maxDepth int) *Spider {

    spider := &Spider{

        baseURL:  baseURL,

        maxDepth: maxDepth,

        queue:    make(chan string),

        visited:  make(map[string]bool),

    }

    return spider

}

func (s *Spider) Run() {

    // 实现爬虫的逻辑

}

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

func (s *Spider) Run() {

    // 将baseURL添加到queue中

    s.queue <- s.baseURL

    for i := 0; i < s.maxDepth; i++ {

        // 循环直到queue为空

        for len(s.queue) > 0 {

            // 从queue中获取URL

            url := <-s.queue

            // 判断URL是否已经访问过

            if s.visited[url] {

                continue

            }

            // 将URL添加到visited中

            s.visited[url] = true

            // 发起HTTP请求，获取响应

            resp, err := http.Get(url)

            if err != nil {

                // 处理错误

                continue

            }

            defer resp.Body.Close()

            // 解析响应内容，提取需要的数据

            body, err := ioutil.ReadAll(resp.Body)

            if err != nil {

                // 处理错误

                continue

            }

            // 提取URL

            urls := extractURLs(string(body))

            // 将提取出来的URL添加到queue中

            for _, u := range urls {

                s.queue <- u

            }

        }

    }

}

1

2

3

4

5

6

7

func main() {

    baseURL := "https://example.com"

    maxDepth := 2

    spider := NewSpider(baseURL, maxDepth)

    spider.Run()

}