执行-运行时错误：无效的内存地址或nil指针取消引用

问题描述：

I am trying to use Go to make a proxy server which changes certain values in the body of a request to an API however when the request is sent the following panic occurs and the request fails:

2015/05/03 14:17:52 http: panic serving 192.168.1.139:42818: runtime error: invalid memory address or nil pointer dereference
goroutine 72 [running]:
net/http.func·011()
    /usr/lib/go/src/pkg/net/http/server.go:1100 +0xb1
runtime.panic(0x8258ee0, 0x83b3733)
    /usr/lib/go/src/pkg/runtime/panic.c:248 +0x176
main.viewResponse(0x0, 0x1861b470, 0x1860ed01)
    /home/bradley/turbocharger/proxy.go:40 +0xa2
github.com/elazarl/goproxy.FuncRespHandler.Handle(0x82e6480, 0x0, 0x1861b470, 0x1)
    /home/bradley/gopath/src/github.com/elazarl/goproxy/actions.go:35 +0x39
github.com/elazarl/goproxy.func·016(0x0, 0x1861b470, 0x827a768)
    /home/bradley/gopath/src/github.com/elazarl/goproxy/dispatcher.go:279 +0x18f
github.com/elazarl/goproxy.FuncRespHandler.Handle(0x1868c9b0, 0x0, 0x1861b470, 0x4)
    /home/bradley/gopath/src/github.com/elazarl/goproxy/actions.go:35 +0x39
github.com/elazarl/goproxy.(*ProxyHttpServer).filterResponse(0x18682640, 0x0, 0x1861b470, 0x0)
    /home/bradley/gopath/src/github.com/elazarl/goproxy/proxy.go:69 +0x95
github.com/elazarl/goproxy.(*ProxyHttpServer).ServeHTTP(0x18682640, 0xb74dd780, 0x18601260, 0x18600bd0)
    /home/bradley/gopath/src/github.com/elazarl/goproxy/proxy.go:115 +0x39b
net/http.serverHandler.ServeHTTP(0x18681dc0, 0xb74dd780, 0x18601260, 0x18600bd0)
    /usr/lib/go/src/pkg/net/http/server.go:1673 +0x155
net/http.(*conn).serve(0x18628a00)
    /usr/lib/go/src/pkg/net/http/server.go:1174 +0x8c6
created by net/http.(*Server).Serve
    /usr/lib/go/src/pkg/net/http/server.go:1721 +0x2be

Here is the script:

func viewResponse(response *http.Response, ctx *goproxy.ProxyCtx) *http.Response {
    log.Printf("Response: %s", response.Status)

    return response
}

我正在尝试使用Go制作代理服务器，该代理服务器会更改对API的请求正文中的某些值但是，发送请求时，会发生以下紧急情况，并且请求失败： p>

  2015/05/03 14:17:52 http：紧急服务192.168.1.139:42818：运行时 错误：无效的内存地址或nil指针取消引用
goroutine 72 [正在运行]：
net / http.func·011（）
 /usr/lib/go/src/pkg/net/http/server.go:1100 + 0xb1  
runtime.panic（0x8258ee0，0x83b3733）
 /usr/lib/go/src/pkg/runtime/panic.c:248 + 0x176 
main.viewResponse（0x0，0x1861b470，0x1860ed01）
 / home / bradley / turbocharger  /proxy.go:40 + 0xa2 
github.com/elazarl/goproxy.FuncRespHandler.Handle（0x82e6480，0x0，0x1861b470，0x1）
 /home/bradley/gopath/src/github.com/elazarl/goproxy/actions。 转到：35 + 0x39 
github.com/elazarl/goproxy.func·016（0x0，0x1861b470，0x827a768）
 /home/bradley/gopath/src/github.com/elazarl/goproxy/dispatcher.go:279 + 0x18f  
github.com/elaz  arl / goproxy.FuncRespHandler.Handle（0x1868c9b0、0x0、0x1861b470、0x4）
 /home/bradley/gopath/src/github.com/elazarl/goproxy/actions.go:35 + 0x39 
github.com/elazarl/goproxy  。（* ProxyHttpServer）.filterResponse（0x18682640、0x0、0x1861b470、0x0）
 /home/bradley/gopath/src/github.com/elazarl/goproxy/proxy.go:69 + 0x95 
github.com/elazarl/goproxy  。（* ProxyHttpServer）.ServeHTTP（0x18682640、0xb74dd780、0x18601260、0x18600bd0）
 /home/bradley/gopath/src/github.com/elazarl/goproxy/proxy.go:115 + 0x39b 
net / http.serverHandler.ServeHTTP  （0x18681dc0、0xb74dd780、0x18601260、0x18600bd0）
 /usr/lib/go/src/pkg/net/http/server.go:1673 + 0x155 
net / http。（* conn）.serve（0x18628a00）
 /  usr / lib / go / src / pkg / net / http / server.go：1174 + 0x8c6 
由net / http创建。（* Server）.Serve 
 / usr / lib / go / src / pkg / net / http  /server.go:1721 + 0x2be 
  code>  pre> 
 
 以下是脚本： p> 
 
 
  func viewResponse（response * http  .Response，ctx * goproxy.ProxyCtx）* http.Response {
 log.Printf（“ Response：％s”，resp  onse.Status）
 
返回响应
} 
  code>  pre> 
  div>

答

response is nil.

From the doc: "In case of error, resp will be nil, and ctx.RoundTrip.Error will contain the error." https://github.com/elazarl/goproxy/blob/master/actions.go#L22-L28

So the correct way to implement your response handler is something like this:

func viewResponse(response *http.Response, ctx *goproxy.ProxyCtx) *http.Response {
    if response == nil {
        log.Printf("Error: %s", ctx.RoundTrip.Error)
    } else {
        log.Printf("Response: %s", response.Status)
    }
    return response
}

执行-运行时错误：无效的内存地址或nil指针取消引用

相关推荐