英文:
Count increased by 2, expecting 1
问题
我正在按照书上的例子进行操作。它假设在输入 http://localhost:8080/xxx 时会增加计数，并在输入 http://localhost:8080/count 时返回计数值。
以下是代码：
var count int
var mu sync.Mutex
func main() {
http.HandleFunc("/", handler)
http.HandleFunc("/count", counter)
log.Fatal(http.ListenAndServe("localhost:8080", nil))
}
func handler(w http.ResponseWriter, req *http.Request) {
mu.Lock()
fmt.Fprintf(w, "Count before: %d\n", count)
count++
fmt.Fprintf(w, "Count after: %d\n", count)
mu.Unlock()
fmt.Fprintf(w, "URL.Path = %q\n", req.URL.Path)
}
func counter(w http.ResponseWriter, req *http.Request) {
mu.Lock()
fmt.Fprintf(w, "Count: %d\n", count)
mu.Unlock()
}
然而，当我打开 http://localhost:8080 并刷新页面时，每次计数增加的是2而不是1。这是 Chrome 浏览器的某个特性吗？
英文:
I am following the example from the book. It supposes to increase the count when type something http://localhost:8080/xxx and return the count number when type http://localhost:8080/count
The code is below
var count int
var mu sync.Mutex
func main() {
http.HandleFunc("/", handler)
http.HandleFunc("/count", counter)
log.Fatal(http.ListenAndServe("localhost:8080", nil))
}
func handler(w http.ResponseWriter, req *http.Request) {
mu.Lock()
fmt.Fprintf(w, "Count before: %d\n", count)
count++
fmt.Fprintf(w, "Count after: %d\n", count)
mu.Unlock()
fmt.Fprintf(w, "URL.Path = %q\n", req.URL.Path)
}
func counter(w http.ResponseWriter, req *http.Request) {
mu.Lock()
fmt.Fprintf(w, "Count: %d\n", count)
mu.Unlock()
}
However, when I open http://localhost:8080 and refresh, count is increase by 2 each time instead of 1. Is this some feature in Chrome?
答案1
得分: 3
Chrome会自动尝试获取网站的favicon图标，这会导致计数器再次增加。
你可以通过按下F12并转到“Network”选项卡，在加载页面之前查看：
这是Chrome开发工具的一部分：https://developers.google.com/web/tools/chrome-devtools/
要测试这段代码，我建议使用curl命令，如下：curl -XGET http://localhost:8080/
英文:
Chrome automatically tries to fetch the favicon, increasing the counter a second time
You can see it by pressing F12 and going to the "Network" tab before loading the page:
(this is part of the Chrome dev tools: https://developers.google.com/web/tools/chrome-devtools/)
To test that exact code, I'd advise using curl like this : curl -XGET http://localhost:8080/
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