无法通过密钥获得大猩猩会话值

Question

我无法通过这种方式从会话中获得价值,它是nil:

session := initSession(r)
valWithOutType := session.Values[key]

完整代码:

package main

import (
    "fmt"
    "github.com/gorilla/mux"
    "github.com/gorilla/sessions"
    "log"
    "net/http"
)

func main() {
    rtr := mux.NewRouter()
    rtr.HandleFunc("/setSession", handler1).Methods("GET")
    rtr.HandleFunc("/getSession", handler2).Methods("GET")
    http.Handle("/", rtr)
    log.Println("Listening...")
    http.ListenAndServe(":3000", http.DefaultServeMux)
}

func handler1(w http.ResponseWriter, r *http.Request) {
    SetSessionValue(w, r, "key", "value")
    w.Write([]byte("setSession"))
}

func handler2(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("getSession"))
    value := GetSessionValue(w, r, "key")
    fmt.Println("value from session")
    fmt.Println(value)
}

var authKey = []byte("secret") // Authorization Key

var encKey = []byte("encKey") // Encryption Key

var store = sessions.NewCookieStore(authKey, encKey)

func initSession(r *http.Request) *sessions.Session {
    store.Options = &sessions.Options{
        MaxAge:   3600 * 1, // 1 hour
        HttpOnly: true,
    }
    session, err := store.Get(r, "golang_cookie")
    if err != nil {
        panic(err)
    }

    return session
}

func SetSessionValue(w http.ResponseWriter, r *http.Request, key, value string) {
    session := initSession(r)
    session.Values[key] = value
    fmt.Printf("set session with key %s and value %s\n", key, value)
    session.Save(r, w)
}

func GetSessionValue(w http.ResponseWriter, r *http.Request, key string) string {
    session := initSession(r)
    valWithOutType := session.Values[key]
    fmt.Printf("valWithOutType: %s\n", valWithOutType)
    value, ok := valWithOutType.(string)
    if !ok {
        fmt.Println("cannot get session value by key: " + key)
    }
    return value
}

输出:

myMac ~/forStack/session $ go run ./session.go
2015/01/30 16:47:26 Listening...

首先,我打开网址http://localhost:3000/setSession并获取输出:

set session with key key and value value

然后我打开url http://localhost:3000/getSession并获得输出:

valWithOutType: %!s(<nil>)
cannot get session value by key: key
value from session

为什么valWithOutType是零,虽然我设定它要求/setSession？

更新

我根据@isza答案更改了代码,但会话值仍然是nil.

package main

import (
    "fmt"
    "github.com/gorilla/mux"
    "github.com/gorilla/sessions"
    "log"
    "net/http"
)

func main() {
    rtr := mux.NewRouter()
    rtr.HandleFunc("/setSession", handler1).Methods("GET")
    rtr.HandleFunc("/getSession", handler2).Methods("GET")
    http.Handle("/", rtr)
    log.Println("Listening...")
    store.Options = &sessions.Options{
        MaxAge:   3600 * 1, // 1 hour
        HttpOnly: true,
        Path:     "/", // to match all requests
    }
    http.ListenAndServe(":3000", http.DefaultServeMux)

}

func handler1(w http.ResponseWriter, r *http.Request) {
    SetSessionValue(w, r, "key", "value")
    w.Write([]byte("setSession"))
}

func handler2(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("getSession"))
    value := GetSessionValue(w, r, "key")
    fmt.Println("value from session")
    fmt.Println(value)
}

var authKey = []byte("secret") // Authorization Key

var encKey = []byte("encKey") // Encryption Key

var store = sessions.NewCookieStore(authKey, encKey)

func initSession(r *http.Request) *sessions.Session {
    session, err := store.Get(r, "golang_cookie")
    if err != nil {
        panic(err)
    }
    return session
}

func SetSessionValue(w http.ResponseWriter, r *http.Request, key, value string) {
    session := initSession(r)
    session.Values[key] = value
    fmt.Printf("set session with key %s and value %s\n", key, value)
    session.Save(r, w)
}

func GetSessionValue(w http.ResponseWriter, r *http.Request, key string) string {
    session := initSession(r)
    valWithOutType := session.Values[key]
    fmt.Printf("valWithOutType: %s\n", valWithOutType)
    value, ok := valWithOutType.(string)
    if !ok {
        fmt.Println("cannot get session value by key: " + key)
    }
    return value
}

Answer 1

在您的initSession()函数中，您可以更改商店选项：

store.Options = &sessions.Options{
    MaxAge:   3600 * 1, // 1 hour
    HttpOnly: true,
}

该结构还包含cookie 将应用的Options重要字段。Path如果不设置它，它的默认值将为空字符串：""。这很可能会导致 cookie 不会与您的任何 url/路径匹配，因此无法找到您现有的会话。

添加一个路径来匹配您的所有网址，如下所示：

store.Options = &sessions.Options{
    Path:     "/",      // to match all requests
    MaxAge:   3600 * 1, // 1 hour
    HttpOnly: true,
}

此外，您不应该store.Options在每次调用中进行更改initSession()，因为您在每个传入请求中都调用了它。只需在创建时设置一次，store如下所示：

var store = sessions.NewCookieStore(authKey, encKey)

func init() {
    store.Options = &sessions.Options{
        Path:     "/",      // to match all requests
        MaxAge:   3600 * 1, // 1 hour
        HttpOnly: true,
    }
}