相关疑难解决方法(0)

我刚开始学习Go lang,我写了一个小演示,从txt读取图片网址,将网址放入数组,然后将响应保存到文件中.

这是我的代码

package main

import (
"bufio"
"fmt"
"io"
"io/ioutil"
"net/http"
"os"
)

func main() {
fileName := "meinv.txt"
file, _ := os.Open(fileName)

picUrl := make([]string, 2000)
reader := bufio.NewReader(file)
for {
    line, _, err := reader.ReadLine()
    if err != io.EOF {
        fmt.Printf("file load %s \n", line)
        picUrl = append(picUrl, string(line))
    } else {
        file.Close()
        break
    }
}
fmt.Printf("file loaded,read to download \n")
fetchPic(picUrl)

}
func fetchPic(picUrl []string) {

var file string
for key, value := range picUrl { …

我试图在Golang Web应用程序中使用mysqlstore后端程序包进行gorilla会话.我正在关注这个例子,我的代码是相同的.代码构建和运行正常,但当我去localhost:8080 /在我的浏览器中我收到此错误

运行时错误:无效的内存地址或无指针取消引用

这是我的代码:

package main

  import (
    "fmt"
    "github.com/srinathgs/mysqlstore"
    "net/http"
  )

  var store *mysqlstore.MySQLStore

  func sessTest(w http.ResponseWriter, r *http.Request) {
    session, err := store.Get(r, "foobar")
    session.Values["bar"] = "baz"
    session.Values["baz"] = "foo"
    err = session.Save(r, w)
    fmt.Printf("%#v\n", session)
    fmt.Println(err)
  }

func main() {

    store, err := mysqlstore.NewMySQLStore("root:mypass@tcp(127.0.0.1:3306)/mydb?parseTime=true&loc=Local", "sessions", "/", 3600, []byte("<SecretKey>"))
    if err != nil {
      panic(err)
    }
    defer store.Close()

        http.HandleFunc("/", sessTest)
        http.ListenAndServe(":8080", nil)
}

这是完整的错误消息:

2019/02/12 02:46:43 http:panic serving [:: 1]:63119:运行时错误:无效的内存地址或无指针取消引用goroutine 34 [运行]:net/http.(*conn).serve.func1 (0xc000112320)/usr/local/Cellar/go/1.11.5/libexec/src/net/http/server.go:1746 + 0xd0 …