使用HTTP协议和Golang列出OrientDB数据库。

huangapple go评论76阅读模式
英文:

list OrientDb databases using HTTP protocol and golang

问题

我正在尝试使用HTTP协议获取OrientDb数据库列表。但是我无法获得预期的响应,而在浏览器中可以获得。

如果我在浏览器地址栏中输入http://localhost:2480/listDatabases,我会得到以下响应:

{"@type":"d","@version":0,"databases":["MaximDB","GratefulDeadConcerts"],"@fieldTypes":"databases=e"}

我该如何使用golang获得相同的响应?

我的代码:

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
)

func main() {
	client := &http.Client{}
	req, err := http.NewRequest("GET", "http://localhost:2480/listDatabases", nil)
	req.SetBasicAuth("root", "1")
	resp, err := client.Do(req)
	if err != nil {
		fmt.Printf("Error : %s", err)
	}
	fmt.Println("resp")
	fmt.Println(ToJson(resp))
}

func ToJson(obj interface{}) string {
	b, err := json.MarshalIndent(&obj, "", "   ")
	if err != nil {
		fmt.Printf("Error : %s", err)
	}
	strJson := string(b)

	return strJson
}

它在控制台输出:

resp
{
   "Status": "200 OK",
   "StatusCode": 200,
   "Proto": "HTTP/1.1",
   "ProtoMajor": 1,
   "ProtoMinor": 1,
   "Header": {
      "Connection": [
         "Keep-Alive"
      ],
      "Content-Type": [
         "application/json; charset=utf-8"
      ],
      "Date": [
         "Fri Jun 05 22:19:23 MSK 2015"
      ],
      "Etag": [
         "0"
      ],
      "Server": [
         "OrientDB Server v.2.0.10 (build UNKNOWN@r; 2015-05-25 16:48:43+0000)"
      ],
      "Set-Cookie": [
         "OSESSIONID=-; Path=/; HttpOnly"
      ]
   },
   "Body": {},
   "ContentLength": -1,
   "TransferEncoding": null,
   "Close": false,
   "Trailer": null,
   "Request": {
      "Method": "GET",
      "URL": {
         "Scheme": "http",
         "Opaque": "",
         "User": null,
         "Host": "localhost:2480",
         "Path": "/listDatabases",
         "RawQuery": "",
         "Fragment": ""
      },
      "Proto": "HTTP/1.1",
      "ProtoMajor": 1,
      "ProtoMinor": 1,
      "Header": {
         "Authorization": [
            "Basic cm9vdDox"
         ]
      },
      "Body": null,
      "ContentLength": 0,
      "TransferEncoding": null,
      "Close": false,
      "Host": "localhost:2480",
      "Form": null,
      "PostForm": null,
      "MultipartForm": null,
      "Trailer": null,
      "RemoteAddr": "",
      "RequestURI": "",
      "TLS": null
   },
   "TLS": null
}
英文:

I am trying to get a list of OrientDb databases using HTTP protocol. But I cannot get expected response, which I can get in a browser.

If I input in a browser address line http://localhost:2480/listDatabases then I have
response:

{"@type":"d","@version":0,"databases":["MaximDB","GratefulDeadConcerts"],"@fieldTypes":"databases=e"}

How can I get the same using golang?

My code:

package main

import (
	"encoding/json"
	"fmt"
	"net/http"
)

func main() {
	client := &http.Client{}
	req, err := http.NewRequest("GET", "http://localhost:2480/listDatabases", nil)
	req.SetBasicAuth("root", "1")
	resp, err := client.Do(req)
	if err != nil {
		fmt.Printf("Error : %s", err)
	}
	fmt.Println("resp")
	fmt.Println(ToJson(resp))
}

func ToJson(obj interface{}) string {
	b, err := json.MarshalIndent(&obj, "", "   ")
	if err != nil {
		fmt.Printf("Error : %s", err)
	}
	strJson := string(b)

	return strJson
}

It outputs in console:

resp
{
   "Status": "200 OK",
   "StatusCode": 200,
   "Proto": "HTTP/1.1",
   "ProtoMajor": 1,
   "ProtoMinor": 1,
   "Header": {
      "Connection": [
         "Keep-Alive"
      ],
      "Content-Type": [
         "application/json; charset=utf-8"
      ],
      "Date": [
         "Fri Jun 05 22:19:23 MSK 2015"
      ],
      "Etag": [
         "0"
      ],
      "Server": [
         "OrientDB Server v.2.0.10 (build UNKNOWN@r; 2015-05-25 16:48:43+0000)"
      ],
      "Set-Cookie": [
         "OSESSIONID=-; Path=/; HttpOnly"
      ]
   },
   "Body": {},
   "ContentLength": -1,
   "TransferEncoding": null,
   "Close": false,
   "Trailer": null,
   "Request": {
      "Method": "GET",
      "URL": {
         "Scheme": "http",
         "Opaque": "",
         "User": null,
         "Host": "localhost:2480",
         "Path": "/listDatabases",
         "RawQuery": "",
         "Fragment": ""
      },
      "Proto": "HTTP/1.1",
      "ProtoMajor": 1,
      "ProtoMinor": 1,
      "Header": {
         "Authorization": [
            "Basic cm9vdDox"
         ]
      },
      "Body": null,
      "ContentLength": 0,
      "TransferEncoding": null,
      "Close": false,
      "Host": "localhost:2480",
      "Form": null,
      "PostForm": null,
      "MultipartForm": null,
      "Trailer": null,
      "RemoteAddr": "",
      "RequestURI": "",
      "TLS": null
   },
   "TLS": null
}

答案1

得分: 2

您的请求是正确的,问题在于您尝试打印响应的方式。

您将整个响应对象转换为JSON,可以看到"Body": {},其中缺少了您的正文部分。*http.Response不会按照您期望的方式转换为JSON。这是因为Body字段不仅仅是一个string[]bytes,它是一个io.ReadCloser,而JSON转换代码不会调用.Read方法。

尝试以下方法只获取响应正文:

var b bytes.Buffer
_, err = b.ReadFrom(resp.Body)
if err != nil {
    log.Fatal("Error: %s", err)
}
fmt.Println(b.String())

或者

contents, err := ioutil.ReadAll(resp.Body)
if err != nil {
    log.Fatal("Error: %s", err)
}
fmt.Println(string(contents))

要获取额外的响应元信息,您可以这样做:

dump, err := httputil.DumpResponse(resp, true)
if err != nil {
    log.Fatal("Error: %s", err)
}
fmt.Println(string(dump))

(第二个参数true表示包括正文,否则只会显示状态和头信息)

英文:

Your request is fine, it's the way you're trying to print out the response.

You're marshaling the entire response object to JSON and you can see the "Body": {}, where your body is missing. A *http.Response won't marshal to JSON the way you want. This is because the Body field is not just a string or []bytes, it's an io.ReadCloser and the JSON marshaling code isn't going to call .Read on it.

Try one of these to just get the response body

var b bytes.Buffer
_, err = b.ReadFrom(resp.Body)
if err != nil {
	log.Fatal("Error : %s", err)
}
fmt.Println(b.String())

or

contents, err := ioutil.ReadAll(resp.Body)
if err != nil {
	log.Fatal("Error : %s", err)
}
fmt.Println(string(contents))

Or to get the extra response meta information you could do this

dump, err := httputil.DumpResponse(resp, true)
if err != nil {
	log.Fatal("Error : %s", err)
}
fmt.Println(string(dump))

(The second flag the true says to include the body, otherwise it would just show status and headers)

huangapple
  • 本文由 发表于 2015年6月6日 02:30:01
  • 转载请务必保留本文链接:https://go.coder-hub.com/30673437.html
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