golang之net/http模块学习

开启服务

package mainimport ("fmt""net/http"
)//路由
func handler(w http.ResponseWriter, r *http.Request){fmt.Fprintf(w, "hello World!")
}func main(){//路由http.HandleFunc("/", handler)//开启服务http.ListenAndServe(":8091", nil) //port:8091(自定义,注意:要是空闲端口)
}

#启动服务
go run main.go

这样本地的8091端口就可以访问了

开启访问静态文件

我们这里拿video来举例

package mainimport ("fmt""net/http"
)func main(){//静态文件访问fs := http.FileServer(http.Dir("./assets"))http.Handle("/static/", http.StripPrefix("/static/", fs))//开启服务http.ListenAndServe(":8091", nil)
}

按照图上的访问路径(http://localhost:8091/static/video/20231204-134423.mp4)

获取现在时间

package mainimport ("fmt""time"
)func main(){currentTime := time.Now()fmt.Println("当前的时间为",currentTime)
}

因为currentTime是time.Time类型所以要想页面输出要进行字符串转换

//获取时间
func getNowTime(w http.ResponseWriter, r *http.Request){currentTime := time.Now()timeString := currentTime.Format("2006-01-02 15:04:05")//"2006-01-02 15:04:05"只是时间格式化字符串格式fmt.Fprintf(w,timeString)
}

至于这个函数上面命名也是如此,就当是net/http路由服务的固定格式便好
注意: Golang函数首字符大写代表着公开(public)小写代表着私有(private)

按时间创建一个空的json文件

package mainimport ("fmt""time"
//	"encoding/json""os"
)func CreateFileNil(){currentTime := GetTime()fileName := currentTime.Format("2006-01-02_15-04-05") + ".json"file,err := os.Create("./assets/json/"+fileName)if err != nil {fmt.Println("JSON编码失败:", err)return}defer file.Close() //defer:表示函数的最后执行(这里是确保最后文件是关闭的)
}func main(){CreateFileNil()
}

按时间创建一个固定值的json文件

package mainimport ("fmt""time""encoding/json""os"
)type Person struct {Name stringAge int
}
//创建一个固定值的json文件
func CreateFileGuDin(){currentTime := GetTime()fileName := currentTime.Format("2006-01-02_15-04-05") + ".json"file,err := os.Create("./assets/json/"+fileName)if err != nil {fmt.Println("JSON编码失败:", err)return}defer file.Close()person := Person{Name: "Alice", Age: 25}jsonData, err := json.Marshal(person)if err != nil {fmt.Println("JSON编码失败:", err)return}_, err = file.Write(jsonData)if err != nil {fmt.Println("写入文件失败:", err)return}fmt.Println("JSON文件创建成功:", fileName)
}func main(){CreateFileGuDin()
}

跨域请求处理

package mainimport ("fmt""net/http"
)//路由
func handler(w http.ResponseWriter, r *http.Request){fmt.Fprintf(w, "hello World!")
}func main(){//创建一个处理跨域请求的处理器函数corsHandler := func(h http.Handler) http.Handler {return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {// 设置允许跨域的域名w.Header().Set("Access-Control-Allow-Origin", "*")// 允许的请求方法w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")// 允许的请求头w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")// 如果是预检请求，直接返回if r.Method == "OPTIONS" {return}h.ServeHTTP(w, r)})}//路由http.Handle("/", corsHandler(http.HandlerFunc(handler)))//开启服务http.ListenAndServe(":8091", nil)
}

输出是json

package mainimport ("fmt""net/http""encoding/json"
)type FileDetail struct{NowTime string `json:"now_time"`FileName string `json:"file_name"`
}func func_name1(w http.ResponseWriter, r *http.Request){responseData := FileDetail {NowTime:"2023_12_04_22_51_30.json",FileName:"http://"+local+":" + port + "/static/video/20231204-19.mp4"}w.Header().Set("Content-Type", "application/json")w.WriteHeader(http.StatusOK)json.NewEncoder(w).Encode(responseData)
}func main(){//创建一个处理跨域请求的处理器函数corsHandler := func(h http.Handler) http.Handler {return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {// 设置允许跨域的域名w.Header().Set("Access-Control-Allow-Origin", "*")// 允许的请求方法w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")// 允许的请求头w.Header().Set("Access-Control-Allow-Headers", "Content-Type, Authorization")// 如果是预检请求，直接返回if r.Method == "OPTIONS" {return}h.ServeHTTP(w, r)})}http.Handle("/test", corsHandler(http.HandlerFunc(func_name1)))//开启服务http.ListenAndServe(":8091", nil)
}