Google App Engine Go PostForm不发送任何url.Values吗？

Question

I have a simple function in GAE golang:

func Call(c appengine.Context, guid string, function string, parameters map[string]string) string {
    client:=urlfetch.Client(c)
    values := url.Values{}
    c.Infof("%v", parameters)
    for k, v := range parameters {
        values.Set(k, v)
    }
    c.Infof("%v", values)
    resp, err:=client.PostForm("https://blockchain.info/merchant/"+guid+"/"+function, values)
    var answer string
    if err != nil {
        c.Errorf("BlockchainAPI post error: %s", err)
    }
    c.Infof("%v", resp.Request.PostForm)
    [...]

I get these printouts:

2013/10/14 23:17:51 INFO: map[main_password:password]
2013/10/14 23:17:51 INFO: map[main_password:[password]]
2013/10/14 23:17:52 INFO: https://blockchain.info/merchant/guid/function
2013/10/14 23:17:52 INFO: map[]

It looks as if client.PostForm does not pass values to the request and not get them back in response. What can be causing this error?

Answer 1

`client.PostForm` uses the body not the request.PostForm values.

It says so in the [documentation][1] :

 // PostForm contains the parsed form data from POST or PUT
 // body parameters.
 // This field is only available after ParseForm is called.
 // The HTTP client ignores PostForm and uses Body instead.
 PostForm url.Values

So your code needs to change from:

c.Infof("%v", resp.Request.PostForm)

To something like this (I haven't tested it for accuracy in the string handling): bd, _ := ioUtil.ReadAll(resp.Body) c.Infof("%v", string(bd[:len(bd)])