go语言学习例子No.25–页面实时获取系统信息2

接着上一个例子

上一个例子是通过ajax请求函数返回数据

现在改成golang里写内容到本地的status.json里，然后ajax直接读取status.json

知识点

http.HandleFunc绑定文件路径

jQuery的getJson方法

js内容

$(function (){
    setInterval(myajax, 2000);
    function myajax(){
        $.getJSON('/status.json',function(data,status){
            if (status == 'success') {
                $('#cpu').text("Cpu: "+data.Cpuused+"%")
                $('#disk').text("Disk: "+data.Diskused+"% used "+data.Diskfree+"G/"+ data.Disktotal+"G")
                $('#mem').text("Memory: "+data.Memused+"% used "+data.Memavailable+"G/"+ data.Memtotal+"G")
                $('#net').text("总下载: "+data.Netsend+"G | 总上传: "+data.Netrecv+"G")
                $('#speed').text("下载: "+data.Netdown+" | 上传: "+data.Netup)
            }
        });
    };
});

main.go

package main

import (
	"bufio"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"strconv"
	"text/template"
	"time"

	"github.com/shirou/gopsutil/cpu"
	"github.com/shirou/gopsutil/disk"
	"github.com/shirou/gopsutil/mem"
	"github.com/shirou/gopsutil/net"
)

type Sys struct {
	Cpuused      float64
	Memused      float64
	Memavailable float64
	Memtotal     float64
	Disktotal    float64
	Diskfree     float64
	Diskused     float64
	Netsend      float64
	Netrecv      float64
	Netup        string
	Netdown      string
}

func index(w http.ResponseWriter, r *http.Request) {
	t, _ := template.ParseFiles("index.html") //找模板
	t.Execute(w, nil)                         //执行模板
}


func main() {
	http.Handle("/assets/", http.StripPrefix("/assets/", http.FileServer(http.Dir("assets"))))
	http.HandleFunc("/status.json", func(w http.ResponseWriter, r *http.Request) {
		http.ServeFile(w, r, r.URL.Path[1:])
	})
	http.HandleFunc("/", index)      //函数也是一种变量
	go setjson(2)//开一个协程，因为主程序不会退出，协程又是死循环，所以协程会一直在执行
	http.ListenAndServe(":8082", nil)
}

func toG(i uint64) float64 {
	return float64(i) / 1024 / 1024 / 1024
}
func toKB(i uint64) float64 {
	return float64(i) / 1024
}
func toMB(i uint64) float64 {
	return float64(i) / 1024 / 1024
}
func Decimal(value float64) float64 {
	value, _ = strconv.ParseFloat(fmt.Sprintf("%.2f", value), 64)
	return value
}
func getNetSpeed() (string, string) {
	// 读取所有网卡网速
	Net, _ := net.IOCounters(true)
	// 定义网速保存变量
	var rx, tx uint64
	// 循环网络信息
	for _, nv := range Net {
		// 去除多余信息
		if "eth0" == nv.Name {
			// 加上网速信息
			rx += nv.BytesRecv
			tx += nv.BytesSent
		}
	}
	// 暂停一秒
	time.Sleep(time.Second)
	// 重新读取网络信息
	Net, _ = net.IOCounters(true)
	// 网络信息保存变量
	var rx2, tx2 uint64
	// 循环网络信息
	for _, nv := range Net {
		// 去除多余信息
		if "eth0" == nv.Name {
			// 加上网速信息
			rx2 += nv.BytesRecv
			tx2 += nv.BytesSent
		}
	}
	// 两次相减
	if toKB(rx2-rx) > 1024 || toKB(tx2-tx) > 1024 {
		down:= strconv.FormatFloat(toMB(rx2 - rx),'f',2,64)+"MB/S"
		up:= strconv.FormatFloat(toMB(tx2 - tx),'f',2,64)+"MB/S"
		return down, up
	} else {
		down:= strconv.FormatFloat(toKB(rx2 - rx),'f',2,64)+"KB/S"
		up:= strconv.FormatFloat(toKB(tx2 - tx),'f',2,64)+"KB/S"
		return down, up
	}

}
func getstatus() Sys {
	s := Sys{}
	m, _ := mem.VirtualMemory()
	c, _ := cpu.Percent(time.Second, false)
	d, _ := disk.Usage("/")
	n, _ := net.IOCounters(true)
	s.Netsend = Decimal(toG(n[1].BytesSent))
	s.Netrecv = Decimal(toG(n[1].BytesRecv))
	s.Diskused = Decimal(d.UsedPercent)
	s.Diskfree = Decimal(toG(d.Free))
	s.Disktotal = Decimal(toG(d.Total))
	s.Memused = Decimal(m.UsedPercent)
	s.Memtotal = Decimal(toG(m.Total))
	s.Memavailable = Decimal(toG(m.Available))
	s.Cpuused = Decimal(c[0])
	s.Netdown, s.Netup = getNetSpeed()
	return s

}

func writefile(f string) { //创建文件再写入
	filePath := "status.json"
	file, err := os.OpenFile(filePath, os.O_RDWR|os.O_CREATE|os.O_SYNC|os.O_TRUNC, 0666)
	if err != nil {
		fmt.Println("open file err", err)
	}
	//及时关闭file句柄
	defer file.Close()

	//写入文件时，使用带缓存的 *Writer
	write := bufio.NewWriter(file)
	write.WriteString(f)
	//Flush将缓存的文件真正写入到文件中
	write.Flush()
}

func setjson(t int)  {//定时写入json
	s:=&Sys{}
	for  {
		time.Sleep(time.Second*time.Duration(t))
		*s = getstatus()
		d, _ := json.Marshal(s)
		writefile(string(d))
	}

}