Golang并发Web服务器开发实战

package main
<p>import (
"fmt"
"log"
"net/http"
"time"
)</p><p>func handler(w http.ResponseWriter, r <em>http.Request) {
// 模拟耗时操作，如数据库查询
time.Sleep(2 </em> time.Second)
fmt.Fprintf(w, "Hello from %s at %s", r.URL.Path, time.Now())
}</p><p>func main() {
http.HandleFunc("/", handler)
log.Println("Server starting on :8080")
log.Fatal(http.ListenAndServe(":8080", nil))
}</p>

var sem = make(chan struct{}, 10) // 最多允许10个并发
<p>func limitedHandler(w http.ResponseWriter, r *http.Request) {
sem <- struct{}{}        // 获取许可
defer func() { <-sem }() // 处理完释放</p><pre class='brush:php;toolbar:false;'>time.Sleep(2 * time.Second)
fmt.Fprintf(w, "Processed: %s", r.URL.Path)

func loggingMiddleware(next http.HandlerFunc) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        log.Printf("%s %s %s", r.RemoteAddr, r.Method, r.URL)
        next(w, r)
    }
}
<p>// 使用中间件
http.HandleFunc("/", loggingMiddleware(handler))</p>

import _ "net/http/pprof"
<p>// 单独启动调试端口
go func() {
log.Println(http.ListenAndServe("localhost:6060", nil))
}()</p>