Go语言实现简单留言板的方法

package main
import (
    // "fmt"
    "io"
    "log"
    "net/http"
    "text/template"
    "time"
    "database/sql"
    "github.com/ziutek/mymysql/godrv"
)
   
// 留言结构
type Liuyan struct {
    Id int
    Name string
    Content string
    Time int
}
   
// 显示留言时间
func (l Liuyan) ShowTime() string {
    t := time.Unix(int64(l.Time), 0)
    return t.Format("2006-01-02 15:04:05")
}
   
func main() {
    godrv.Register("SET NAMES utf8")
   
    // 连接数据库
    db, err := sql.Open("mymysql", "tcp:127.0.0.1:3306*go/root/123456")
    if err != nil {
        panic(err)
    }
    defer db.Close()
   
    // 准备模板
    tpl, err := template.New("liuyanbook").Parse(html)
    if err != nil {
        panic(err)
    }
   
    // 显示留言页面 /
    requestList := func(w http.ResponseWriter, req *http.Request) {
        // 查询数据
        rows, err := db.Query("select * from liuyan")
        if err != nil {
            log.Fatal(err)
        }
        defer rows.Close()
   
        // 获取数据
        lys := []Liuyan{}
        for rows.Next() {
            ly := Liuyan{}
            err := rows.Scan(ly.Id, ly.Name, ly.Content, ly.Time)
            if nil != err {
                log.Fatal(err)
            }
            lys = append(lys, ly)
        }
   
        // 显示数据
        err = tpl.ExecuteTemplate(w, "list", lys)
        if err != nil {
            log.Fatal(err)
        }
    }
   
    // 留言页面 /liuyan
    requestLiuyan := func(w http.ResponseWriter, req *http.Request) {
        err := req.ParseForm()
        if err != nil{
            log.Fatal(err)
        }
   
        if "POST" == req.Method {
            if len(req.Form["name"]) 1 {
                io.WriteString(w, "参数错误!\n")
                return
            }
            if len(req.Form["content"]) 1 {
                io.WriteString(w, "参数错误!\n")
                return
            }
   
            name := template.HTMLEscapeString(req.Form.Get("name"))
            content := template.HTMLEscapeString(req.Form.Get("content"))
   
            // sql语句
            sql, err := db.Prepare("insert into liuyan(name, content, time) values(?, ?, ?)")
            if err != nil {
                log.Fatal(err)
            }
            defer sql.Close()
   
            // sql参数,并执行
            _, err = sql.Exec(name, content, time.Now().Unix())
            if err != nil {
                log.Fatal(err)
            }
   
            // 跳转
            w.Header().Add("Location", "/")
            w.WriteHeader(302)
   
            // 提示信息
            io.WriteString(w, "提交成功!\n")
   
            return
        }
   
        err = tpl.ExecuteTemplate(w, "liuyan", nil)
        if err != nil {
            log.Fatal(err)
        }
    }
   
    http.HandleFunc("/", requestList)
    http.HandleFunc("/liuyan", requestLiuyan)
    err = http.ListenAndServe(":12345", nil)
    if err != nil {
        log.Fatal("ListenAndServe: ", err)
    }
}
   
// 网页模板
var html string = `{{define "list"}}{{/* 留言列表页面 */}}!DOCTYPE html>
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=utf-8">
/head>
body>
    p>a href="/liuyan">给我留言/a>/p>
    table>
{{range .}}
    tr>
        td>{{.Id}}/td>td>{{.Name}}/td>td>{{.Content}}/td>td>{{.ShowTime}}/td>
    /tr>
{{end}}
    /table>
/body>
/html>{{end}}
{{define "liuyan"}}{{/* 发布留言页面 */}}!DOCTYPE html>
html>
head>
meta http-equiv="Content-Type" content="text/html; charset=utf-8">
/head>
body>
    form method="post">
        姓名:input type="text" name="name" />br>
        内容:input type="text" name="content" />br>
        input type="submit" value="提交" />
    /form>
/body>
/html>{{end}}