我用一些CRUD方法編寫了一個(gè)簡(jiǎn)單的MongoDB軟件包：package backendimport "labix.org/v2/mgo"type MongoDBConn struct { session *mgo.Session}type ToDo struct { Title string Description string}func NewMongoDBConn() *MongoDBConn { return &MongoDBConn{}}func (m *MongoDBConn) Connect(url string) *mgo.Session { session, err := mgo.Dial(url) if err != nil { panic(err) } m.session = session return m.session}func (m *MongoDBConn) Stop() { m.session.Close()}func (m *MongoDBConn) AddToDo(title, description string) (err error) { c := m.session.DB("test").C("people") err = c.Insert(&ToDo{title, description}) if err != nil { panic(err) } return nil}我有一個(gè)server.go，在其中創(chuàng)建Http Server并具有用于不同URL的處理程序。我希望能夠連接到MongoDB并在特定處理程序中調(diào)用AddToDo方法。我可以從服務(wù)器的主要方法連接到數(shù)據(jù)庫(kù)：import ( "./backend" //other boilerplate imports)func AddHandler(writer http.ResponseWriter, request *http.Request) { log.Printf("serving %v %v", request.Method, request.URL.Path[1:]) if request.Method != "POST" { serve404(writer) return } title := request.FormValue("title") description := request.FormValue("description") fmt.Fprintf(writer, " title description %v %v", title, description)//I can't call mongoConn.AddToDo(title, description) from here} func main() { //connect to mongoDB mongoConn := backend.NewMongoDBConn() _ = mongoConn.Connect("localhost") defer mongoConn.Stop() }但是我不確定如何從處理程序中調(diào)用mongoConn.AddToDo（title，description string）方法。我應(yīng)該創(chuàng)建一個(gè)全局?jǐn)?shù)據(jù)庫(kù)連接變量嗎？
2 回答
倚天杖
TA貢獻(xiàn)1828條經(jīng)驗(yàn) 獲得超3個(gè)贊
兩種簡(jiǎn)單的方法：
1.全局?jǐn)?shù)據(jù)庫(kù)會(huì)話
package main
import (
"net/http"
"log"
"fmt"
"./backend"
)
var mongoConn * backend.MongoDBConn
func AddHandler(w http.ResponseWriter, r *http.Request) {
log.Printf("serving %v %v", r.Method, r.URL.Path[1:])
if r.Method != "POST" {
fmt.Fprintln(w, "Not POST Method ")
return
}
title := r.FormValue("title")
description := r.FormValue("description")
fmt.Fprintf(w, " title description %v %v", title, description)
//I can't call mongoConn.AddToDo(title, description) from here
mongoConn.AddToDo(title, description)
}
const AddForm = `
<html><body>
<form method="POST" action="/add">
Name: <input type="text" name="title">
Age: <input type="text" name="description">
<input type="submit" value="Add">
</form>
</body></html>
`
func Index(w http.ResponseWriter, r *http.Request) {
fmt.Fprintln(w, AddForm)
}
func main() {
//connect to mongoDB
mongoConn = backend.NewMongoDBConn()
_ = mongoConn.Connect("localhost")
defer mongoConn.Stop()
http.HandleFunc("/", Index)
http.HandleFunc("/add", AddHandler)
log.Println("Start Server:")
err := http.ListenAndServe(":8080", nil)
if err != nil {
log.Fatal("ListenAndServe:", err)
}
}
2.每個(gè)請(qǐng)求都有一個(gè)新的數(shù)據(jù)庫(kù)連接
import (
"./backend"
//other boilerplate imports
)
func AddHandler(writer http.ResponseWriter, request *http.Request) {
log.Printf("serving %v %v", request.Method, request.URL.Path[1:])
if request.Method != "POST" {
serve404(writer)
return
}
title := request.FormValue("title")
description := request.FormValue("description")
fmt.Fprintf(writer, " title description %v %v", title, description)
//................
mongoConn := backend.NewMongoDBConn()
_ = mongoConn.Connect("localhost")
mongoConn.AddToDo(title, description)
//....................
mongoConn.Stop()
}
......
更好的解決方案：
您可以創(chuàng)建一個(gè)數(shù)據(jù)庫(kù)會(huì)話池，然后在處理請(qǐng)求之前選擇一個(gè)并放入該請(qǐng)求的上下文中。然后，在完成請(qǐng)求后，將連接推回池中。
如果該池為空，則創(chuàng)建一個(gè)新的連接；如果該池已滿，則關(guān)閉該連接
慕田峪4524236
TA貢獻(xiàn)1875條經(jīng)驗(yàn) 獲得超5個(gè)贊
是的，全球會(huì)議是處理此問題的簡(jiǎn)便方法。然后，在每個(gè)處理程序的頂部，您可以執(zhí)行以下操作：
func handler(...) {
session := globalSession.Copy()
defer session.Close()
}
這樣每個(gè)處理程序都可以使用自己的會(huì)話。
請(qǐng)注意，復(fù)制和關(guān)閉會(huì)話是廉價(jià)的操作，在內(nèi)部將對(duì)連接池起作用，而不是為每個(gè)創(chuàng)建的會(huì)話建立新的連接。
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