net.connect

net.connect

Function

Establish a TCP, UDP or WebSocket client connection.

Syntax

Parameters

Parameters	Type	Required	Default value	Description
config	Object	Yes	None	Connection configuration object. Public fields and protocol fields are shown below.

Connection configuration field

Field	Type	Applicable type	Required	Default value	Description
type	String	All	Yes	None	The connection protocol type. Optional values are `tcp`, `udp`, `ws`.
host	String	tcp/udp	Yes	None	Remote host name or IP address, such as `127.0.0.1`, `example.com`.
port	Int	tcp/udp	Yes	None	The remote port number, ranging from 0 to 65535.
timeout	Int	tcp	No	`0`	TCP connection, read and write timeout, in milliseconds; less than or equal to 0 means no timeout is set.
url	String	ws	Yes	None	WebSocket full connection address, such as `ws://127.0.0.1:9002/ws`.

Return Value

Type	Description
TcpClient/UdpSocket/WsSocket	Press `type` to return the corresponding connection handle.

Connection handle field

Field	Type	Description
addr	String	Connection target or local socket address, usually in the format `host:port`.
type	String	Connection type. TCP returns `tcp`, UDP returns `udp`, and WebSocket returns `ws`.

Connection handle method

Type	Method	Return value	Description
TcpClient	write(data) / send(data)	Int	Writes a TCP String, byte array, or Bytes, returning the number of bytes written.
TcpClient	read()	String	Synchronously read a piece of TCP data and convert it to a string according to UTF-8 lossy.
TcpClient	read_bytes()	Bytes	Synchronously read a segment of TCP raw bytes.
TcpClient	close()	Bool	Close the TCP connection.
UdpSocket	send(data)	Int	Send UDP data to the default remote address in the connect configuration and return the number of bytes sent.
UdpSocket	send(data, addr)	Int	Send UDP data to the specified `host:port` and return the number of bytes sent.
UdpSocket	close()	Bool	Close UDP socket.
WsSocket	send(data) / write(data)	Bool	Send WebSocket message; String is text frame, Bytes or byte array is binary frame.
WsSocket	close()	Bool	Close the WebSocket connection.
WsSocket	on_message(fn(message) {}, binary)	WsSocket	Register WebSocket client message callback; when the second parameter is true, message is Bytes.
WsSocket	on_close(fn() {})	WsSocket	Register the WebSocket client close callback.
WsSocket	on_error(fn(message) {})	WsSocket	Register WebSocket client error callback.

Examples

Notes

- TCP and UDP use the host, port fields; WebSocket uses the full url field.

- WebSocket does not support synchronous read(); please receive messages via on_message().

When you need to receive binary messages, TCP can use read_bytes(), and the listening callback can set binary: true in the net.listen configuration.