Golang's HTTP Operations encyclopedia

This is a creation in Article, where the information may have evolved or changed.

Golang provides the official HTTP package, which is very convenient and concise for HTTP operation.
But unlike PHP, using Golang's package to do HTTP operations, or not so "direct", need to instantiate this, instantiate that, a bit like Java , therefore, in order to write convenient later, the basic request is written here. The next time you use it, copy it directly.

GET request

There are several ways of GET requests

Directly using net/http function requests within a package

123	Import "Net/http"... resp, err: = http. Get ("http://wwww.baidu.com")

Use the http.client structure to request

1234	Import "Net/http"... clt: = http. CLIENT{}RESP, err: = CLT. Get ("http://wwww.baidu.com")

The most essential way to request

If you take a look at the source code, you will find that both of these methods use the most essential form of the request, using the http.NewRequest function

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Req, Err: = http. Newrequest ("GET""http://www.baidu.com"nil)//And then http.client the Do method of the struct body http. Defaultclient can be swapped for another http.clientresp, err: = http. Defaultclient.do (req)

There are several request methods on the GET request surface of go, but there is only one:

1. Using http.NewRequest functions to get request entities

2, using the http.client structure of the Do method, the request entity passed into the Do method.

POST request

Similar to get requests, there are several ways to post requests, but the http.NewRequest function and methods are used http.client in essence Do .

Using net/http the Post method of the package band

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Import ("net/http""Net/url") ... data: = URL. values{"Start": {"0""offset": {"xxxx"}}body: = Strings. Newreader (data. Encode ()) resp, err: = http. Post ("xxxxxxx" "application/x-www-form-urlencoded", body)

Or you can

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Import ("Net/http""net/url") ... var r http. Requestr.parseform () r.form.add ("xxx""xxx") Body: = Strings. Newreader (R.form.encode ()) HTTP. Post ("xxxx""application/x-www-form-urlencoded", body)

If you still feel complex, you can:

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Import ("net/http""Net/url") ... data: = URL. values{"Start": {"0""offset": {"xxxx"}}http. Postform ("xxxx", data)

Post method using the instantiated HTTP client

In fact, the function of directly using the package and the instantiation of the HTTP client is the same, the function of the bottom of the package is simply instantiating a DefaultClient , and then call the DefaultClient method. The Post method for using the instantiated HTTP client is given below:

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Import ("net/http""Net/url") ... data: = URL. values{"Start": {"0""offset": {"xxxx"}}body: = Strings. Newreader (data. Encode ()) CLT: = http. CLIENT{}RESP, err: = CLT. Post ("xxxxxxx" "application/x-www-form-urlencoded", body)

And also

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Import ("Net/http""net/url") ... var r http. Requestr.parseform () r.form.add ("xxx""xxx") Body: = Strings. Newreader (R.form.encode ()) CLT: = http. CLIENT{}CLT. Post ("xxxx""application/x-www-form-urlencoded", body)

Simple, but limited to form form forms

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Import ("net/http""Net/url") ... data: = URL. values{"Start": {"0""offset": {"xxxx"}}clt: = http. CLIENT{}CLT. Postform ("xxxx", data)

net/httpfunctions that use packages NewRequest

In fact, whether it is the Get method or the Post method, all get, post HTTP request form, the final will be called the function of the package, a net/http NewRequest variety of request forms, but also only the package is different.

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Import ("net/http""Net/url") ... data: = URL. values{"Start": {"0""offset": {"xxxx"}}body: = Strings. Newreader (data. Encode ()) req, err: = http. Newrequest ("POST""xxxxx", body) req. Header.set ("Content-type""application/x-www-form-urlencoded") CLT: = http. CLIENT{}CLT. Do (req)

Add Request Header

net/httpPackages are not encapsulated directly using a GET or POST method that requests a header, so you can only use the method if you want the header in the request NewRequest .

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import ( "net/http" ) ... req, err: = http. Newrequest ( "POST" , , body) / /req can also be written here. Header.set ("User-agent", "MyClient") req. Header.add ( "User-agent" , ) CLT: = http. CLIENT{}CLT. Do (req)

One thing to note: When adding a header operation, req.Header.Add and req.Header.Set all can, but when modifying the operation, can only be used req.Header.Set .
The two methods are different, golang the implementation of the bottom header is a map[string][]string , req.Header.Set method if the original header has no value, then it is no problem, if the value, will replace the original value. And then, on the basis of the req.Header.Add original value, then append a value, for example, the value of the original header is "s", I later req.Header.Add a "a" words, became [s a] . However, the method to get the header value is req.Header.Get only the first, so if there is a value, re- req.Header.Add a new value, the req.Header.Get resulting value is the same.

Print response response

Golang print response not as good as PHP, eh, compiled language is trouble.

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Import ("net/http""Net/url""io/ioutil"string(content)

Using cookies

Golang provides a packet of cookiesnet/http/cookiejar

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... URL, err: = URL. Parse ("https://www.wukong.com/") jar, err: = Cookiejar. New (nil) jar. Setcookies (URL, cookies)//The cookies here are []*http. CookieWUKONGCLT: = http. Client{transport:Nil, Jar:jar}wukongclt.get ("xxxxx")

The type of the text cookies [] *http.cookie can be instantiated by itself, and sometimes can be directly used from the direct to response resp.Cookies() get.

Golang's cookie is http.client associated with http.client a property that exists as an attribute. Therefore, in order to use cookies in Golang, we must find ways to constructhttp.client

Using proxies

To use HTTP proxy in Golang, you must also construct your own http.client , and you need to http.client instantiate a property of the struct Transport itself.

When using environment variables $http_proxy or $http_proxy as proxies

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//Get the HTTP proxy address from the environment variable $http_proxy or $http_proxy funcgettransportfromenvironment()(transport *http. Transport) {Transport = &http. Transport{proxy:http. Proxyfromenvironment}return}

When you build an HTTP proxy using your own

Parameter proxy_addr is the proxy server IP port number, for example: "http://xxx.xxx.xxx.xxx:6000", note that the "HTTP" must be added

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func Gettransportfieldurl (PROXY_ADDR *string) (Transport *http. Transport) {url_i: = URL. Url{}url_proxy, Error: = Url_i.parse (*proxy_addr)ifnil{fmt. PRINTLN (Error. Error ())}transport = &http. Transport{proxy:http. Proxyurl (Url_proxy)}return}

When using, first call the function, get the corresponding transport , that is, use GetTransportFieldURL or GetTransportFieldURL function, and then build the custom http.client :

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Proxyurl: = "http://xxx.xxx.xxx.xxx:6000" Transport: = Gettransportfieldurl (& Proxyurl) CLT: = http. CLIENT{TRANSPORT:TRANSPORT}CLT. Get ( "http://www.baidu.com" )