[[atmosphere-websocket-component]]
== Atmosphere Websocket Component

*Available as of Camel version 2.14*

The *atmosphere-websocket:* component provides Websocket
based endpoints for a servlet communicating with
external clients over Websocket (as a servlet accepting websocket
connections from external clients). +
The component uses the <<servlet-component,SERVLET>> component and uses
the https://github.com/Atmosphere/atmosphere[Atmosphere] library to
support the Websocket transport in various Servlet containers (e..g.,
Jetty, Tomcat, ...).

Unlike the
https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=39621544[Websocket]
component that starts the embedded Jetty server, this component uses the
servlet provider of the container.

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

[source,xml]
------------------------------------------------------------
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-atmosphere-websocket</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
------------------------------------------------------------

### Atmosphere-Websocket Options



// component options: START
The Atmosphere Websocket component supports 10 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *servletName* (consumer) | Default name of servlet to use. The default name is CamelServlet. | CamelServlet | String
| *httpRegistry* (consumer) | To use a custom org.apache.camel.component.servlet.HttpRegistry. |  | HttpRegistry
| *attachmentMultipart Binding* (consumer) | Whether to automatic bind multipart/form-data as attachments on the Camel Exchange. The options attachmentMultipartBinding=true and disableStreamCache=false cannot work together. Remove disableStreamCache to use AttachmentMultipartBinding. This is turn off by default as this may require servlet specific configuration to enable this when using Servlet's. | false | boolean
| *fileNameExtWhitelist* (consumer) | Whitelist of accepted filename extensions for accepting uploaded files. Multiple extensions can be separated by comma, such as txt,xml. |  | String
| *httpBinding* (advanced) | To use a custom HttpBinding to control the mapping between Camel message and HttpClient. |  | HttpBinding
| *httpConfiguration* (advanced) | To use the shared HttpConfiguration as base configuration. |  | HttpConfiguration
| *allowJavaSerialized Object* (advanced) | Whether to allow java serialization when a request uses context-type=application/x-java-serialized-object. This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. | false | boolean
| *headerFilterStrategy* (filter) | To use a custom org.apache.camel.spi.HeaderFilterStrategy to filter header to and from Camel message. |  | HeaderFilterStrategy
| *resolveProperty Placeholders* (advanced) | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | boolean
| *basicPropertyBinding* (advanced) | Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | boolean
|===
// component options: END




// endpoint options: START
The Atmosphere Websocket endpoint is configured using URI syntax:

----
atmosphere-websocket:servicePath
----

with the following path and query parameters:

==== Path Parameters (1 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *servicePath* | *Required* Name of websocket endpoint |  | String
|===


==== Query Parameters (25 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *sendToAll* (common) | Whether to send to all (broadcast) or send to a single receiver. | false | boolean
| *useStreaming* (common) | To enable streaming to send data as multiple text fragments. | false | boolean
| *disableStreamCache* (common) | Determines whether or not the raw input stream from Servlet is cached or not (Camel will read the stream into a in memory/overflow to file, Stream caching) cache. By default Camel will cache the Servlet input stream to support reading it multiple times to ensure it Camel can retrieve all data from the stream. However you can set this option to true when you for example need to access the raw stream, such as streaming it directly to a file or other persistent store. DefaultHttpBinding will copy the request input stream into a stream cache and put it into message body if this option is false to support reading the stream multiple times. If you use Servlet to bridge/proxy an endpoint then consider enabling this option to improve performance, in case you do not need to read the message payload multiple times. The http/http4 producer will by default cache the response body stream. If setting this option to true, then the producers will not cache the response body stream but use the response stream as-is as the message body. | false | boolean
| *headerFilterStrategy* (common) | To use a custom HeaderFilterStrategy to filter header to and from Camel message. |  | HeaderFilterStrategy
| *httpBinding* (common) | To use a custom HttpBinding to control the mapping between Camel message and HttpClient. |  | HttpBinding
| *async* (consumer) | Configure the consumer to work in async mode | false | boolean
| *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. | false | boolean
| *chunked* (consumer) | If this option is false the Servlet will disable the HTTP streaming and set the content-length header on the response | true | boolean
| *httpMethodRestrict* (consumer) | Used to only allow consuming if the HttpMethod matches, such as GET/POST/PUT etc. Multiple methods can be specified separated by comma. |  | String
| *matchOnUriPrefix* (consumer) | Whether or not the consumer should try to find a target consumer by matching the URI prefix if no exact match is found. | false | boolean
| *responseBufferSize* (consumer) | To use a custom buffer size on the javax.servlet.ServletResponse. |  | Integer
| *servletName* (consumer) | Name of the servlet to use | CamelServlet | String
| *transferException* (consumer) | If enabled and an Exchange failed processing on the consumer side, and if the caused Exception was send back serialized in the response as a application/x-java-serialized-object content type. On the producer side the exception will be deserialized and thrown as is, instead of the HttpOperationFailedException. The caused exception is required to be serialized. This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. | false | boolean
| *attachmentMultipartBinding* (consumer) | Whether to automatic bind multipart/form-data as attachments on the Camel Exchange. The options attachmentMultipartBinding=true and disableStreamCache=false cannot work together. Remove disableStreamCache to use AttachmentMultipartBinding. This is turn off by default as this may require servlet specific configuration to enable this when using Servlet's. | false | boolean
| *eagerCheckContentAvailable* (consumer) | Whether to eager check whether the HTTP requests has content if the content-length header is 0 or not present. This can be turned on in case HTTP clients do not send streamed data. | false | boolean
| *exceptionHandler* (consumer) | 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) | Sets the exchange pattern when the consumer creates an exchange. |  | ExchangePattern
| *fileNameExtWhitelist* (consumer) | Whitelist of accepted filename extensions for accepting uploaded files. Multiple extensions can be separated by comma, such as txt,xml. |  | String
| *optionsEnabled* (consumer) | Specifies whether to enable HTTP OPTIONS for this Servlet consumer. By default OPTIONS is turned off. | false | boolean
| *traceEnabled* (consumer) | Specifies whether to enable HTTP TRACE for this Servlet consumer. By default TRACE is turned off. | false | boolean
| *basicPropertyBinding* (advanced) | Whether the endpoint should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | boolean
| *mapHttpMessageBody* (advanced) | If this option is true then IN exchange Body of the exchange will be mapped to HTTP body. Setting this to false will avoid the HTTP mapping. | true | boolean
| *mapHttpMessageFormUrl EncodedBody* (advanced) | If this option is true then IN exchange Form Encoded body of the exchange will be mapped to HTTP. Setting this to false will avoid the HTTP Form Encoded body mapping. | true | boolean
| *mapHttpMessageHeaders* (advanced) | If this option is true then IN exchange Headers of the exchange will be mapped to HTTP headers. Setting this to false will avoid the HTTP Headers mapping. | true | boolean
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
|===
// endpoint options: END
// spring-boot-auto-configure options: START
=== Spring Boot Auto-Configuration

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

[source,xml]
----
<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-atmosphere-websocket-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>
----


The component supports 11 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *camel.component.atmosphere-websocket.allow-java-serialized-object* | Whether to allow java serialization when a request uses context-type=application/x-java-serialized-object. This is by default turned off. If you enable this then be aware that Java will deserialize the incoming data from the request to Java and that can be a potential security risk. | false | Boolean
| *camel.component.atmosphere-websocket.attachment-multipart-binding* | Whether to automatic bind multipart/form-data as attachments on the Camel Exchange. The options attachmentMultipartBinding=true and disableStreamCache=false cannot work together. Remove disableStreamCache to use AttachmentMultipartBinding. This is turn off by default as this may require servlet specific configuration to enable this when using Servlet's. | false | Boolean
| *camel.component.atmosphere-websocket.basic-property-binding* | Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | Boolean
| *camel.component.atmosphere-websocket.enabled* | Enable atmosphere-websocket component | true | Boolean
| *camel.component.atmosphere-websocket.file-name-ext-whitelist* | Whitelist of accepted filename extensions for accepting uploaded files. Multiple extensions can be separated by comma, such as txt,xml. |  | String
| *camel.component.atmosphere-websocket.header-filter-strategy* | To use a custom org.apache.camel.spi.HeaderFilterStrategy to filter header to and from Camel message. The option is a org.apache.camel.spi.HeaderFilterStrategy type. |  | String
| *camel.component.atmosphere-websocket.http-binding* | To use a custom HttpBinding to control the mapping between Camel message and HttpClient. The option is a org.apache.camel.http.common.HttpBinding type. |  | String
| *camel.component.atmosphere-websocket.http-configuration* | To use the shared HttpConfiguration as base configuration. The option is a org.apache.camel.http.common.HttpConfiguration type. |  | String
| *camel.component.atmosphere-websocket.http-registry* | To use a custom org.apache.camel.component.servlet.HttpRegistry. The option is a org.apache.camel.component.servlet.HttpRegistry type. |  | String
| *camel.component.atmosphere-websocket.resolve-property-placeholders* | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | Boolean
| *camel.component.atmosphere-websocket.servlet-name* | Default name of servlet to use. The default name is CamelServlet. | CamelServlet | String
|===
// spring-boot-auto-configure options: END



### URI Format

[source,java]
-----------------------------------------------
atmosphere-websocket:///relative path[?options]
-----------------------------------------------

### Reading and Writing Data over Websocket

An atmopshere-websocket endpoint can either write data to the socket or
read from the socket, depending on whether the endpoint is configured as
the producer or the consumer, respectively.

### Configuring URI to Read or Write Data

In the route below, Camel will read from the specified websocket
connection.

[source,java]
-------------------------------------------
from("atmosphere-websocket:///servicepath")
        .to("direct:next");
-------------------------------------------

And the equivalent Spring sample:

[source,xml]
------------------------------------------------------------
<camelContext xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="atmosphere-websocket:///servicepath"/>
    <to uri="direct:next"/>
  </route>
</camelContext>
------------------------------------------------------------

In the route below, Camel will read from the specified websocket
connection.

[source,java]
---------------------------------------------------
from("direct:next")
        .to("atmosphere-websocket:///servicepath");
---------------------------------------------------

And the equivalent Spring sample:

[source,xml]
------------------------------------------------------------
<camelContext xmlns="http://camel.apache.org/schema/spring">
  <route>
    <from uri="direct:next"/>
    <to uri="atmosphere-websocket:///servicepath"/>
  </route>
</camelContext>
------------------------------------------------------------

 

### See Also

* Configuring Camel
* Component
* Endpoint
* Getting Started

* <<servlet-component,SERVLET>>
* <<ahc-ws-component,AHC-WS>>
*
https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=39621544[Websocket]
