golang sends request

Go is an open source programming language that is very suitable for writing efficient, reliable, and concurrent network applications. Due to its excellent performance and ease of writing, Go has become the programming language of choice for many applications. In this article, we will cover how to send HTTP requests using Go.

1. First introduce the net/http package

The first step to send HTTP requests in Go is to introduce the net/http package. It provides many features, including creating HTTP clients and servers, etc.

import "net/http"

2. Create HTTP client

To create an HTTP client, we need to use the http.Client structure. It can be created using:

client := &http.Client{}

There are also many options in the client that can be modified. For example, you can set timeouts, use proxy servers, etc. Here is an example with timeouts and a proxy server.

timeout := time.Duration(5 * time.Second)
transport := &http.Transport{

Proxy: http.ProxyURL(proxyUrl),

}
client := &http.Client{

Timeout:   timeout,
Transport: transport,

}

Please note that proxy server is optional. If you do not need to use a proxy server, you can directly use an empty proxy URL:

proxyUrl, err := url.Parse("")

3. Send HTTP GET request

Now that we have created the HTTP client, we can start sending requests. The simplest request is the HTTP GET request, we use the Get function to send the GET request.

resp, err := client.Get("https://www.example.com/path/to/resource")

func main() {

resp, err := http.Get("https://www.example.com/path/to/resource")
if err != nil {
        // handle error
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
        // handle error
}
fmt.Println(string(body))

}

If the request is successful, the server will return a response. Contents, such as the response status code and response body, can be read from the response. Note: The resp.Body.Close() method must be called after reading the response body to release the response body resources.

4. Send HTTP POST request

In addition to GET requests, you can also send HTTP POST requests. POST requests are typically used to submit data to the server. We can use the Post function to create a POST request as follows:

values ​​:= map[string]string{"username": "Administrator", "password": "Password"}
jsonValue , _ := json.Marshal(values)
url := "http://example.com/login"
req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonValue ))
req.Header.Set("Content-Type", "application/json")

func main() {

values := map[string]string{"username": "管理员", "password": "密码"}
jsonValue, _ := json.Marshal(values)
resp, err := http.Post("http://example.com/login", "application/json", bytes.NewBuffer(jsonValue))
if err != nil {
        // handle error
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
        // handle error
}
fmt.Println(string(body))

}

above In the code, we use the NewRequest function to create a POST request. We pass the request body to the bytes.NewBuffer function, where the body is encoded using JSON format. We then set the Content-Type header to "application/json" so that the server knows that the body of the request is in JSON format.

5. Send other types of HTTP requests

In Go, you can send other types of HTTP requests, such as PUT, DELETE, PATCH, OPTIONS, HEAD, etc. To send these requests, we can use the http.NewRequest function. Here is an example of sending a JSON file using a PUT request:

values ​​:= map[string]string{"name": "John Doe", "age": "29"}
jsonValue, _ := json.Marshal(values)
req, err := http.NewRequest("PUT", "http://example.com/users/123", bytes.NewBuffer(jsonValue))
req. Header.Set("Content-Type", "application/json")

func main() {

values := map[string]string{"name": "John Doe", "age": "29"}
jsonValue, _ := json.Marshal(values)
req, err := http.NewRequest("PUT", "http://example.com/users/123", bytes.NewBuffer(jsonValue))
if err != nil {
        // handle error
}
req.Header.Set("Content-Type", "application/json")
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
        // handle error
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
        // handle error
}
fmt.Println(string(body))

}

To send DELETE, PATCH, OPTIONS and HEAD request, just change the first parameter in the http.NewRequest function to the relevant HTTP method. For example, to send a DELETE request, change the first parameter to "DELETE".

6. Conclusion

In this article, we introduced how to send HTTP requests using Go. We created an HTTP client and sent HTTP GET and POST requests to the server. We also covered how to send other types of HTTP requests, such as PUT, DELETE, PATCH, OPTIONS, HEAD, etc.

In actual development, more options and functions are usually needed. This can be achieved by setting different properties of the http.Client structure. Using these methods, you can easily send HTTP requests in Go, and handle the responses. Whether you are building a web application, a distributed system, a backend service, or any other network application, you can easily get the job done with Go.

The above is the detailed content of golang sends request. For more information, please follow other related articles on the PHP Chinese website!