Platform HTTP

Since Camel 3.0

Only consumer is supported

The Platform HTTP is used to allow Camel to use the existing HTTP server from the runtime. For example, when running Camel on Spring Boot, Quarkus, or other runtimes.

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

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

Platform HTTP Provider

To use Platform HTTP, a provider (engine) is required to be available on the classpath. The purpose is to have drivers for different runtimes such as Quarkus, or Spring Boot.

To use it with different runtimes:

  • Quarkus

  • Spring Boot

<dependency>
    <groupId>org.apache.camel.quarkus</groupId>
    <artifactId>camel-quarkus-platform-http</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel Quarkus version -->
</dependency>
<dependency>
    <groupId>org.apache.camel.springboot</groupId>
    <artifactId>camel-platform-http-starter</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel version -->
</dependency>

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.

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.

You can configure components using:

  • the Component DSL.

  • in a configuration file (application.properties, *.yaml files, etc).

  • directly in the Java code.

Configuring Endpoint Options

You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.

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

A good practice when configuring options is to use Property Placeholders.

Property placeholders provide a few benefits:

  • They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.

  • They allow externalizing the configuration from the code.

  • They help the code to become more flexible and reusable.

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

Component Options

The Platform HTTP component supports 4 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 (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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

handleWriteResponseError (consumer)

When Camel is complete processing the message, and the HTTP server is writing response. This option controls whether Camel should catch any failure during writing response and store this on the Exchange, which allows onCompletion/UnitOfWork to regard the Exchange as failed and have access to the caused exception from the HTTP server.

false

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.

true

boolean

engine (advanced)

An HTTP Server engine implementation to serve the requests.

PlatformHttpEngine

Endpoint Options

The Platform HTTP endpoint is configured using URI syntax:

platform-http:path

With the following path and query parameters:

Path Parameters (1 parameters)

Name Description Default Type

path (consumer)

Required The path under which this endpoint serves the HTTP requests, for proxy use 'proxy'.

String

Query Parameters (13 parameters)

Name Description Default Type

consumes (consumer)

The content type this endpoint accepts as an input, such as application/xml or application/json. null or */* mean no restriction.

String

handleWriteResponseError (consumer)

When Camel is complete processing the message, and the HTTP server is writing response. This option controls whether Camel should catch any failure during writing response and store this on the Exchange, which allows onCompletion/UnitOfWork to regard the Exchange as failed and have access to the caused exception from the HTTP server.

false

boolean

httpMethodRestrict (consumer)

A comma separated list of HTTP methods to serve, e.g. GET,POST . If no methods are specified, all methods will be served.

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

muteException (consumer)

If enabled and an Exchange failed processing on the consumer side the response’s body won’t contain the exception’s stack trace.

true

boolean

produces (consumer)

The content type this endpoint produces, such as application/xml or application/json.

String

useStreaming (consumer)

Whether to use streaming for large requests and responses (currently only supported by camel-platform-http-vertx).

false

boolean

bridgeErrorHandler (consumer (advanced))

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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

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

ExchangePattern

fileNameExtWhitelist (consumer (advanced))

A comma or whitespace separated list of file extensions. Uploads having these extensions will be stored locally. Null value or asterisk () will allow all files.

String

headerFilterStrategy (advanced)

To use a custom HeaderFilterStrategy to filter headers to and from Camel message.

HeaderFilterStrategy

platformHttpEngine (advanced)

An HTTP Server engine implementation to serve the requests of this endpoint.

PlatformHttpEngine

Spring Boot Auto-Configuration

When using platform-http 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-platform-http-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 5 options, which are listed below.

Name Description Default Type

camel.component.platform-http.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.platform-http.bridge-error-handler

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. 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.platform-http.enabled

Whether to enable auto configuration of the platform-http component. This is enabled by default.

Boolean

camel.component.platform-http.engine

An HTTP Server engine implementation to serve the requests. The option is a org.apache.camel.component.platform.http.spi.PlatformHttpEngine type.

PlatformHttpEngine

camel.component.platform-http.handle-write-response-error

When Camel is complete processing the message, and the HTTP server is writing response. This option controls whether Camel should catch any failure during writing response and store this on the Exchange, which allows onCompletion/UnitOfWork to regard the Exchange as failed and have access to the caused exception from the HTTP server.

false

Boolean

Implementing a reverse proxy

Platform HTTP component can act as a reverse proxy. In that case, some headers are populated from the absolute URL received on the request line of the HTTP request. Those headers are specific to the underlining platform.

At this moment, this feature is only supported for Quarkus implemented in camel-platform-http-vertx component.