Detailed explanation of the characteristics and use of the webSocket client API
Detailed explanation of the characteristics and use of the webSocket client API
WebSocket is a full dual -work protocol based on the TCP protocol. It provides a persistent connection on the transmission layer that can realize real -time and two -way data transmission between clients and servers.The WebSocket client API provides the ability to communicate with the WebSocket server, and provides some features and uses. The following will explain it in detail.
characteristic:
1. Two -way communication: WebSocket client API realizes real two -way communication, allowing real -time two -way data transmission between clients and servers.Compared with the traditional HTTP request-response model, WebSocket allows the server to actively send messages to the client, not just returning response when the client sends a request.
2. Specific connection: WebSocket provides a durable connection method to avoid the overhead of each communication established and closes the connection.Once the WebSocket connection is established, the connection between the client and the server will keep it open until one of them actively close the connection.
3. Low latency: Because WebSocket uses lasting connection and is based on TCP, there is no HTTP protocol for each connection and disconnecting expenses, so low delay real -time communication can be achieved.This makes WebSockets particularly suitable for applications that need to update data in real time, such as chat applications and stock markets.
4. Cross -domain communication: The WebSocket Client API supports cross -domain communication, that is, the client can communicate with servers in different domains.By default, the browser restricts cross -domain communication, but in order to support WebSocket, the browser allows the client to initiate a websock connection from different domains.
use:
1. Real -time chat: Because WebSocket provides low -delay two -way communication capabilities, it has become an ideal choice for real -time chat applications.Through the WebSocket client API, real -time message transmission between users can be realized, so as to achieve instant messaging functions in chat applications.
2. Real -time data display: Many applications need to update data in real time, such as stock markets, instant games, etc.Through the WebSocket client API, real -time data transmission between the client and the server can be realized, and the demand for real -time data display can be achieved.
3. Remote control and collaboration: Websocket can also be used to achieve remote control and collaboration.Through the WebSocket client API, a two -way connection between the client and the server can be established to achieve remote control and collaboration functions.For example, when remotely operating electronic whiteboards or editing sharing documents, WebSocket can provide real -time two -way data transmission.
Java code example:
The following is a simple Java code example, demonstrating how to use the WebSocket client API provided by Java to communicate with the server.
import javax.websocket.ClientEndpoint;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import java.net.URI;
@ClientEndpoint
public class WebSocketClient {
@OnOpen
public void onOpen(Session session) {
System.out.println ("Websocket connection has been opened."););
}
@OnMessage
public void onMessage(String message) {
System.out.println ("Receive messages:" + message);
}
public static void main(String[] args) {
try {
WebSocketContainer container = ContainerProvider.getWebSocketContainer();
String uri = "ws: // localhost: 8080/ws"; // The address of the Websocket server
container.connectToServer(WebSocketClient.class, URI.create(uri));
} catch (Exception e) {
e.printStackTrace();
}
}
}
In the above examples, `@clienendpoint` annotations indicate that this is a WebSocket client class,`@onopen` and@onmessage `indicating the monitoring method of connecting and receiving messages, respectively.In the `Main` method, we create a WebSocket container through the` WebSocketContainer` class, and connect to the specified WebSocket server with the `ConnectToserver` method.
This is just a simple example. Actually, the WebSocket client API may also need to handle connection shutdown and error treatment. The specific implementation will be different according to demand and business logic.
