Vert.x WebSocket

Since Camel 3.5

Both producer and consumer are supported

The Vert.x WebSocket component provides WebSocket capabilities as a WebSocket server, or as a client to connect to existing an WebSocket.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-vertx-websocket</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

vertx-websocket://hostname[:port][/resourceUri][?options]

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The Vert.x WebSocket component supports 7 options, which are listed below.

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

router (advanced)

To provide a custom vertx router to use on the WebSocket server.

Router

vertx (advanced)

To use an existing vertx instead of creating a new instance.

Vertx

vertxOptions (advanced)

To provide a custom set of vertx options for configuring vertx.

VertxOptions

useGlobalSslContextParameters (security)

Enable usage of global SSL context parameters.

boolean

Endpoint Options

The Vert.x WebSocket endpoint is configured using URI syntax:

vertx-websocket:host:port/path

with the following path and query parameters:

Path Parameters (3 parameters)

Name Description Default Type

host (common)

The host that the consumer should bind to or the host of the remote websocket destination that the producer should connect to.

String

port (common)

The port that the consumer should bind to or port of the remote websocket destination that the producer should connect to.

int

path (common)

Required The path that the consumer should bind to or path of the remote websocket destination that the producer should connect to.

String

Query Parameters (11 parameters)

Name Description Default Type

allowedOriginPattern (consumer)

Regex pattern to match the origin header sent by WebSocket clients.

String

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

boolean

router (consumer)

To use an existing vertx router for the HTTP server.

Router

serverOptions (consumer)

Sets customized options for configuring the HTTP server hosting the WebSocket for the consumer.

HttpServerOptions

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

  • InOptionalOut

ExchangePattern

clientOptions (producer)

Sets customized options for configuring the WebSocket client used in the producer.

HttpClientOptions

clientSubProtocols (producer)

Comma separated list of WebSocket subprotocols that the client should use for the Sec-WebSocket-Protocol header.

String

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

sendToAll (producer)

To send to all websocket subscribers. Can be used to configure on endpoint level, instead of having to use the VertxWebsocketConstants.SEND_TO_ALL header on the message.

boolean

sslContextParameters (security)

To configure security using SSLContextParameters.

SSLContextParameters

Message Headers

The WebSocket component uses 2 headers to indicate to either send messages back to a single/current client, or to all clients.

Name Description

VertxWebsocketConstants.SEND_TO_ALL

Sends the message to all clients which are currently connected. You can use the sendToAll option on the endpoint instead of using this header.

VertxWebsocketConstants.CONNECTION_KEY

Sends the message to the client with the given connection key. You can use a comma separated list of keys to send a message to multiple clients

Usage

The following example shows how to expose a WebSocket on http://localhost:8080/echo and returns an 'echo' response back to the same channel:

from("vertx-websocket:localhost:8080/echo")
    .transform().simple("Echo: ${body}")
    .to("vertx-websocket:localhost:8080/echo");

SSL

By default the ws:// protocol is used, but secure connections with wss:// are supported by configuring the consumer or producer via the sslContextParameters URI parameter and the Camel JSSE Configuration Utility

Spring Boot Auto-Configuration

When using vertx-websocket with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel.springboot</groupId>
  <artifactId>camel-vertx-websocket-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 8 options, which are listed below.

Name Description Default Type

camel.component.vertx-websocket.autowired-enabled

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

Boolean

camel.component.vertx-websocket.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

Boolean

camel.component.vertx-websocket.enabled

Whether to enable auto configuration of the vertx-websocket component. This is enabled by default.

Boolean

camel.component.vertx-websocket.lazy-start-producer

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

Boolean

camel.component.vertx-websocket.router

To provide a custom vertx router to use on the WebSocket server. The option is a io.vertx.ext.web.Router type.

Router

camel.component.vertx-websocket.use-global-ssl-context-parameters

Enable usage of global SSL context parameters.

false

Boolean

camel.component.vertx-websocket.vertx

To use an existing vertx instead of creating a new instance. The option is a io.vertx.core.Vertx type.

Vertx

camel.component.vertx-websocket.vertx-options

To provide a custom set of vertx options for configuring vertx. The option is a io.vertx.core.VertxOptions type.

VertxOptions