Configurable websocket url

Question

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no answer in a question about a common scenario

I've a websocket endpoint implemented as:

@ServerEndpoint(
    value="/foo/{id}",
    encoders = { MyEncoder.class },
    decoders = { MyDecoder.class },
    subprotocols = { "foo" }
)
public class MyEndPoint {
...
}

it is working ok. However, I need to move the url /foo/{id} to a config file (lets say web.xml) instead of hard-coded in the value of the @ServerEndpoint annotation.

Any hint? Thanks.

Answer 1

I think it's a similar problem with here (about Request Mapping annotations).

Anyway configuration would be like as follows.

• [MyEndPoint.java]

   @ServerEndpoint( value="${websocket.base_uri}/{id}", // --> `id` is a variable name so it's NOT suit to customize it in config file. encoders = { MyEncoder.class }, decoders = { MyDecoder.class }, subprotocols = { "${websocket.subprotocol}" } ) public class MyEndPoint { private long id; ... }

• [websocket.properties]

   websocket.base_uri=/foo websocket.subprotocol=foo

• [spring-context.xml]

   <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location"> <value>websocket.properties</value> </property> </bean>... </beans>

• [web.xml]

   <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="..." version="3.0"> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/spring-context.xml</param-value> </context-param>... </web-app>

I don't know to include the PathVaraible name - {id} - in config file, and also think that it isn't suit to configurate the variable name in both xml and java files.