How to transmit data in golang

Golang (also known as the Go language) is a programming language for creating efficient and scalable web applications. In web development, transferring data is a very common operation. So, how do we transfer data in Golang? Next, this article will show some methods of transferring data.

1. Transmitting data through HTTP protocol

HTTP is an application-level protocol, mostly used to transmit Web pages and related content. Go language has a built-in HTTP package, which can easily use HTTP to transmit data. The following is a simple HTTP data transmission example:

package main
import (
    "fmt"
    "net/http"
)
func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}
func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, %s!", r.URL.Path[1:])
}

The above code uses the http.HandleFunc() function to specify the HTTP routing processing function, and then uses the http.ListenAndServe() function to start the specified TCP port. monitor. The handler() function is used to specifically handle requests in HTTP routing. Here it simply replies with a "Hello" string. Run the program and enter http://localhost:8080/ in the web browser. You can see "Hello, /!" displayed on the browser, indicating that the data is successfully transmitted through the HTTP protocol.

2. Transmitting data through TCP protocol

TCP (Transmission Control Protocol) is usually used to transmit data streams in the network, and is sometimes called a connection-oriented protocol. The Go language network package includes TCP support. The following is a simple TCP data transmission example:

package main
import (
    "fmt"
    "net"
)
func main() {
    lis, _ := net.Listen("tcp", "localhost:8080")
    defer lis.Close()
    for {
        conn, _ := lis.Accept()
        go handleConnection(conn)
    }
}
func handleConnection(conn net.Conn) {
    buffer := make([]byte, 1024)
    n, _ := conn.Read(buffer)
    fmt.Println(string(buffer[:n]))
    conn.Write([]byte("Hello from server"))
    conn.Close()
}

The above code starts a TCP service on local port 8080 through the net.Listen() function. When the client requests to establish a TCP connection with the server, the server generates a new goroutine process to handle the TCP connection. In the handleConnection() function, the data from the client is read through the conn.Read() function, and then the data is output on the server. Then, reply to the client with a "Hello from server" string through the conn.Write() function. After the client receives the reply, the socket is closed. At this point, the data is successfully transmitted through the TCP protocol.

3. Transmitting data through UDP protocol

UDP is the user datagram protocol. This protocol is connectionless-oriented, so it can be used to transmit datagrams across the network without confirming the recipient. Are you ready to receive data? The Go language network package supports the UDP protocol. The following is a simple UDP data transmission example:

package main
import (
    "fmt"
    "net"
)
func main() {
    addr, _ := net.ResolveUDPAddr("udp", ":8080")
    conn, _ := net.ListenUDP("udp", addr)
    defer conn.Close()
    buffer := make([]byte, 1024)
    n, addr, _ := conn.ReadFromUDP(buffer)
    fmt.Println(string(buffer[0:n]))
    conn.WriteToUDP([]byte("Hello from server"), addr)
}

The above code uses the net.ResolveUDPAddr() function to parse the UDP address, and uses the net.ListenUDP() function to create a read-write UDP data connection. . When the client sends data to the server through this connection, the server reads the data through the conn.ReadFromUDP() function, then performs some processing, and replies with a message through the conn.WriteToUDP() function. After the data is successfully transferred, the UDP connection will be closed.

To sum up, Golang can transmit data through different protocols such as HTTP, TCP and UDP. Programmers can choose appropriate data transmission methods according to different application scenarios and specific needs.

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