Module jakarta.websocket

Package jakarta.websocket.server

Annotation Interface ServerEndpoint

@Retention(RUNTIME)
@Target(TYPE)
public @interface ServerEndpoint

This class level annotation declares that the class it decorates is a web socket endpoint that will be deployed and made available in the URI-space of a web socket server. The annotation allows the developer to define the URL (or URI template) which this endpoint will be published, and other important properties of the endpoint to the websocket runtime, such as the encoders it uses to send messages.

The annotated class must have a public no-arg constructor.

For example:

 
 @ServerEndpoint("/hello");
 public class HelloServer {

     @OnMessage
     public void processGreeting(String message, Session session) {
         System.out.println("Greeting received:" + message);
     }

 }
 
 

Required Element Summary

Required Elements

Modifier and Type	Required Element	Description
String	value	The URI or URI-template, level-1 (See RFC 6570) where the endpoint will be deployed.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
Class<? extends ServerEndpointConfig.Configurator>	configurator	The optional custom configurator class that the developer would like to use to further configure new instances of this endpoint.
Class<? extends Decoder>[]	decoders	The ordered array of decoder classes this endpoint will use.
Class<? extends Encoder>[]	encoders	The ordered array of encoder classes this endpoint will use.
String[]	subprotocols	The ordered array of web socket protocols this endpoint supports.

Element Details

value

String value

The URI or URI-template, level-1 (See RFC 6570) where the endpoint will be deployed. The URI us relative to the root of the web socket container and must begin with a leading "/". Trailing "/"'s are ignored. Examples:

 
 @ServerEndpoint("/chat")
 @ServerEndpoint("/chat/{user}")
 @ServerEndpoint("/booking/{privilege-level}")
 
 

Returns:

the URI or URI-template

subprotocols

String[] subprotocols

The ordered array of web socket protocols this endpoint supports. For example, {"superchat", "chat"}.

Returns:

the subprotocols.

Default:

{}

decoders

Class<? extends Decoder>[] decoders

The ordered array of decoder classes this endpoint will use. For example, if the developer has provided a MysteryObject decoder, this endpoint will be able to receive MysteryObjects as web socket messages. The websocket runtime will use the first decoder in the list able to decode a message, ignoring the remaining decoders.

Returns:

the decoders.

Default:

{}

encoders

Class<? extends Encoder>[] encoders

The ordered array of encoder classes this endpoint will use. For example, if the developer has provided a MysteryObject encoder, this class will be able to send web socket messages in the form of MysteryObjects. The websocket runtime will use the first encoder in the list able to encode a message, ignoring the remaining encoders.

Returns:

the encoders.

Default:

{}

configurator

Class<? extends ServerEndpointConfig.Configurator> configurator

The optional custom configurator class that the developer would like to use to further configure new instances of this endpoint. If no configurator class is provided, the implementation uses its own. The implementation creates a new instance of the configurator per logical endpoint.

Returns:

the custom configuration class, or ServerEndpointConfig.Configurator.class if none was set in the annotation.

Default:

jakarta.websocket.server.ServerEndpointConfig.Configurator.class