Constant

Since Camel 1.5

The Constant Expression Language is really just a way to use a constant value or object.

This is a fixed constant value (or object) that is only set once during starting up the route, do not use this if you want dynamic values during routing.

Constant Options

The Constant language supports 2 options, which are listed below.

Name Default Java Type Description

Name	Default	Java Type	Description
resultType		`String`	Sets the class name of the constant type.
trim		`Boolean`	Whether to trim the value to remove leading and trailing whitespaces and line breaks.

resultType

String

Sets the class name of the constant type.

trim

Boolean

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

Example

The setHeader EIP can utilize a constant expression like:

<route>
  <from uri="seda:a"/>
  <setHeader name="theHeader">
    <constant>the value</constant>
  </setHeader>
  <to uri="mock:b"/>
</route>

in this case, the message coming from the seda:a endpoint will have the header with key theHeader set its value as the value (string type).

And the same example using Java DSL:

from("seda:a")
  .setHeader("theHeader", constant("the value"))
  .to("mock:b");

Specifying type of value

The option resultType can be used to specify the type of the value, when the value is given as a String value, which happens when using XML or YAML DSL:

For example to set a header with int type you can do:

<route>
  <from uri="seda:a"/>
  <setHeader name="zipCode">
    <constant resultType="int">90210</constant>
  </setHeader>
  <to uri="mock:b"/>
</route>

Loading constant from external resource

You can externalize the constant and have Camel load it from a resource such as "classpath:", "file:", or "http:".
This is done using the following syntax: "resource:scheme:location", eg to refer to a file on the classpath you can do:

.setHeader("myHeader").constant("resource:classpath:constant.txt")

Dependencies

The Constant language is part of camel-core.

Spring Boot Auto-Configuration

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

The component supports 144 options, which are listed below.

Name	Description	Default	Type
camel.cloud.consul.service-discovery.acl-token	Sets the ACL token to be used with Consul.		String
camel.cloud.consul.service-discovery.block-seconds	The seconds to wait for a watch event, default 10 seconds.	10	Integer
camel.cloud.consul.service-discovery.configurations	Define additional configuration definitions.		Map
camel.cloud.consul.service-discovery.connect-timeout-millis	Connect timeout for OkHttpClient.		Long
camel.cloud.consul.service-discovery.datacenter	The data center.		String
camel.cloud.consul.service-discovery.enabled	Enable the component.	true	Boolean
camel.cloud.consul.service-discovery.password	Sets the password to be used for basic authentication.		String
camel.cloud.consul.service-discovery.properties	Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.		Map
camel.cloud.consul.service-discovery.read-timeout-millis	Read timeout for OkHttpClient.		Long
camel.cloud.consul.service-discovery.url	The Consul agent URL.		String
camel.cloud.consul.service-discovery.user-name	Sets the username to be used for basic authentication.		String
camel.cloud.consul.service-discovery.write-timeout-millis	Write timeout for OkHttpClient.		Long
camel.cloud.dns.service-discovery.configurations	Define additional configuration definitions.		Map
camel.cloud.dns.service-discovery.domain	The domain name;.		String
camel.cloud.dns.service-discovery.enabled	Enable the component.	true	Boolean
camel.cloud.dns.service-discovery.properties	Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.		Map
camel.cloud.dns.service-discovery.proto	The transport protocol of the desired service.	_tcp	String
camel.cloud.etcd.service-discovery.configurations	Define additional configuration definitions.		Map
camel.cloud.etcd.service-discovery.enabled	Enable the component.	true	Boolean
camel.cloud.etcd.service-discovery.password	The password to use for basic authentication.		String
camel.cloud.etcd.service-discovery.properties	Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.		Map
camel.cloud.etcd.service-discovery.service-path	The path to look for for service discovery.	/services/	String
camel.cloud.etcd.service-discovery.timeout	To set the maximum time an action could take to complete.		Long
camel.cloud.etcd.service-discovery.type	To set the discovery type, valid values are on-demand and watch.	on-demand	String
camel.cloud.etcd.service-discovery.uris	The URIs the client can connect to.		String
camel.cloud.etcd.service-discovery.user-name	The user name to use for basic authentication.		String
camel.cloud.kubernetes.service-discovery.api-version	Sets the API version when using client lookup.		String
camel.cloud.kubernetes.service-discovery.ca-cert-data	Sets the Certificate Authority data when using client lookup.		String
camel.cloud.kubernetes.service-discovery.ca-cert-file	Sets the Certificate Authority data that are loaded from the file when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-cert-data	Sets the Client Certificate data when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-cert-file	Sets the Client Certificate data that are loaded from the file when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-key-algo	Sets the Client Keystore algorithm, such as RSA when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-key-data	Sets the Client Keystore data when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-key-file	Sets the Client Keystore data that are loaded from the file when using client lookup.		String
camel.cloud.kubernetes.service-discovery.client-key-passphrase	Sets the Client Keystore passphrase when using client lookup.		String
camel.cloud.kubernetes.service-discovery.configurations	Define additional configuration definitions.		Map
camel.cloud.kubernetes.service-discovery.dns-domain	Sets the DNS domain to use for DNS lookup.		String
camel.cloud.kubernetes.service-discovery.enabled	Enable the component.	true	Boolean
camel.cloud.kubernetes.service-discovery.lookup	How to perform service lookup. Possible values: client, dns, environment. When using client, then the client queries the kubernetes master to obtain a list of active pods that provides the service, and then random (or round robin) select a pod. When using dns the service name is resolved as name.namespace.svc.dnsDomain. When using dnssrv the service name is resolved with SRV query for .…svc… When using environment then environment variables are used to lookup the service. By default environment is used.	environment	String
camel.cloud.kubernetes.service-discovery.master-url	Sets the URL to the master when using client lookup.		String
camel.cloud.kubernetes.service-discovery.namespace	Sets the namespace to use. Will by default use namespace from the ENV variable KUBERNETES_MASTER.		String
camel.cloud.kubernetes.service-discovery.oauth-token	Sets the OAUTH token for authentication (instead of username/password) when using client lookup.		String
camel.cloud.kubernetes.service-discovery.password	Sets the password for authentication when using client lookup.		String
camel.cloud.kubernetes.service-discovery.port-name	Sets the Port Name to use for DNS/DNSSRV lookup.		String
camel.cloud.kubernetes.service-discovery.port-protocol	Sets the Port Protocol to use for DNS/DNSSRV lookup.		String
camel.cloud.kubernetes.service-discovery.properties	Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.		Map
camel.cloud.kubernetes.service-discovery.trust-certs	Sets whether to turn on trust certificate check when using client lookup.	false	Boolean
camel.cloud.kubernetes.service-discovery.username	Sets the username for authentication when using client lookup.		String
camel.cloud.ribbon.load-balancer.client-name	Sets the Ribbon client name.		String
camel.cloud.ribbon.load-balancer.configurations	Define additional configuration definitions.		Map
camel.cloud.ribbon.load-balancer.enabled	Enable the component.	true	Boolean
camel.cloud.ribbon.load-balancer.namespace	The namespace.		String
camel.cloud.ribbon.load-balancer.password	The password.		String
camel.cloud.ribbon.load-balancer.properties	Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.		Map
camel.cloud.ribbon.load-balancer.username	The username.		String
camel.hystrix.allow-maximum-size-to-diverge-from-core-size	Allows the configuration for maximumSize to take effect. That value can then be equal to, or higher, than coreSize.	false	Boolean
camel.hystrix.circuit-breaker-enabled	Whether to use a HystrixCircuitBreaker or not. If false no circuit-breaker logic will be used and all requests permitted. This is similar in effect to circuitBreakerForceClosed() except that continues tracking metrics and knowing whether it should be open/closed, this property results in not even instantiating a circuit-breaker.	true	Boolean
camel.hystrix.circuit-breaker-error-threshold-percentage	Error percentage threshold (as whole number such as 50) at which point the circuit breaker will trip open and reject requests. It will stay tripped for the duration defined in circuitBreakerSleepWindowInMilliseconds; The error percentage this is compared against comes from HystrixCommandMetrics.getHealthCounts().	50	Integer
camel.hystrix.circuit-breaker-force-closed	If true the HystrixCircuitBreaker#allowRequest() will always return true to allow requests regardless of the error percentage from HystrixCommandMetrics.getHealthCounts(). The circuitBreakerForceOpen() property takes precedence so if it set to true this property does nothing.	false	Boolean
camel.hystrix.circuit-breaker-force-open	If true the HystrixCircuitBreaker.allowRequest() will always return false, causing the circuit to be open (tripped) and reject all requests. This property takes precedence over circuitBreakerForceClosed();.	false	Boolean
camel.hystrix.circuit-breaker-request-volume-threshold	Minimum number of requests in the metricsRollingStatisticalWindowInMilliseconds() that must exist before the HystrixCircuitBreaker will trip. If below this number the circuit will not trip regardless of error percentage.	20	Integer
camel.hystrix.circuit-breaker-sleep-window-in-milliseconds	The time in milliseconds after a HystrixCircuitBreaker trips open that it should wait before trying requests again.	5000	Integer
camel.hystrix.configurations	Define additional configuration definitions.		Map
camel.hystrix.core-pool-size	Core thread-pool size that gets passed to java.util.concurrent.ThreadPoolExecutor#setCorePoolSize(int).	10	Integer
camel.hystrix.enabled	Enable the component.	true	Boolean
camel.hystrix.execution-isolation-semaphore-max-concurrent-requests	Number of concurrent requests permitted to HystrixCommand.run(). Requests beyond the concurrent limit will be rejected. Applicable only when executionIsolationStrategy == SEMAPHORE.	20	Integer
camel.hystrix.execution-isolation-strategy	What isolation strategy HystrixCommand.run() will be executed with. If THREAD then it will be executed on a separate thread and concurrent requests limited by the number of threads in the thread-pool. If SEMAPHORE then it will be executed on the calling thread and concurrent requests limited by the semaphore count.	THREAD	String
camel.hystrix.execution-isolation-thread-interrupt-on-timeout	Whether the execution thread should attempt an interrupt (using Future#cancel ) when a thread times out. Applicable only when executionIsolationStrategy() == THREAD.	true	Boolean
camel.hystrix.execution-timeout-enabled	Whether the timeout mechanism is enabled for this command.	true	Boolean
camel.hystrix.execution-timeout-in-milliseconds	Time in milliseconds at which point the command will timeout and halt execution. If executionIsolationThreadInterruptOnTimeout == true and the command is thread-isolated, the executing thread will be interrupted. If the command is semaphore-isolated and a HystrixObservableCommand, that command will get unsubscribed.	1000	Integer
camel.hystrix.fallback-enabled	Whether HystrixCommand.getFallback() should be attempted when failure occurs.	true	Boolean
camel.hystrix.fallback-isolation-semaphore-max-concurrent-requests	Number of concurrent requests permitted to HystrixCommand.getFallback(). Requests beyond the concurrent limit will fail-fast and not attempt retrieving a fallback.	10	Integer
camel.hystrix.group-key	Sets the group key to use. The default value is CamelHystrix.	CamelHystrix	String
camel.hystrix.keep-alive-time	Keep-alive time in minutes that gets passed to ThreadPoolExecutor#setKeepAliveTime(long,TimeUnit).	1	Integer
camel.hystrix.max-queue-size	Max queue size that gets passed to BlockingQueue in HystrixConcurrencyStrategy.getBlockingQueue(int) This should only affect the instantiation of a threadpool - it is not eliglible to change a queue size on the fly. For that, use queueSizeRejectionThreshold().	-1	Integer
camel.hystrix.maximum-size	Maximum thread-pool size that gets passed to ThreadPoolExecutor#setMaximumPoolSize(int) . This is the maximum amount of concurrency that can be supported without starting to reject HystrixCommands. Please note that this setting only takes effect if you also set allowMaximumSizeToDivergeFromCoreSize.	10	Integer
camel.hystrix.metrics-health-snapshot-interval-in-milliseconds	Time in milliseconds to wait between allowing health snapshots to be taken that calculate success and error percentages and affect HystrixCircuitBreaker.isOpen() status. On high-volume circuits the continual calculation of error percentage can become CPU intensive thus this controls how often it is calculated.	500	Integer
camel.hystrix.metrics-rolling-percentile-bucket-size	Maximum number of values stored in each bucket of the rolling percentile. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.	10	Integer
camel.hystrix.metrics-rolling-percentile-enabled	Whether percentile metrics should be captured using HystrixRollingPercentile inside HystrixCommandMetrics.	true	Boolean
camel.hystrix.metrics-rolling-percentile-window-buckets	Number of buckets the rolling percentile window is broken into. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.	6	Integer
camel.hystrix.metrics-rolling-percentile-window-in-milliseconds	Duration of percentile rolling window in milliseconds. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.	10000	Integer
camel.hystrix.metrics-rolling-statistical-window-buckets	Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside HystrixCommandMetrics.	10	Integer
camel.hystrix.metrics-rolling-statistical-window-in-milliseconds	This property sets the duration of the statistical rolling window, in milliseconds. This is how long metrics are kept for the thread pool. The window is divided into buckets and rolls by those increments.	10000	Integer
camel.hystrix.queue-size-rejection-threshold	Queue size rejection threshold is an artificial max size at which rejections will occur even if maxQueueSize has not been reached. This is done because the maxQueueSize of a BlockingQueue can not be dynamically changed and we want to support dynamically changing the queue size that affects rejections. This is used by HystrixCommand when queuing a thread for execution.	5	Integer
camel.hystrix.request-log-enabled	Whether HystrixCommand execution and events should be logged to HystrixRequestLog.	true	Boolean
camel.hystrix.thread-pool-key	Sets the thread pool key to use. Will by default use the same value as groupKey has been configured to use.	CamelHystrix	String
camel.hystrix.thread-pool-rolling-number-statistical-window-buckets	Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.	10	Integer
camel.hystrix.thread-pool-rolling-number-statistical-window-in-milliseconds	Duration of statistical rolling window in milliseconds. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.	10000	Integer
camel.language.constant.enabled	Whether to enable auto configuration of the constant language. This is enabled by default.		Boolean
camel.language.constant.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.csimple.enabled	Whether to enable auto configuration of the csimple language. This is enabled by default.		Boolean
camel.language.csimple.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.exchange-property.enabled	Whether to enable auto configuration of the exchangeProperty language. This is enabled by default.		Boolean
camel.language.exchange-property.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.file.enabled	Whether to enable auto configuration of the file language. This is enabled by default.		Boolean
camel.language.file.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.header.enabled	Whether to enable auto configuration of the header language. This is enabled by default.		Boolean
camel.language.header.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.ref.enabled	Whether to enable auto configuration of the ref language. This is enabled by default.		Boolean
camel.language.ref.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.simple.enabled	Whether to enable auto configuration of the simple language. This is enabled by default.		Boolean
camel.language.simple.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.language.tokenize.enabled	Whether to enable auto configuration of the tokenize language. This is enabled by default.		Boolean
camel.language.tokenize.group-delimiter	Sets the delimiter to use when grouping. If this has not been set then token will be used as the delimiter.		String
camel.language.tokenize.trim	Whether to trim the value to remove leading and trailing whitespaces and line breaks.	true	Boolean
camel.resilience4j.automatic-transition-from-open-to-half-open-enabled	Enables automatic transition from OPEN to HALF_OPEN state once the waitDurationInOpenState has passed.	false	Boolean
camel.resilience4j.circuit-breaker	Refers to an existing io.github.resilience4j.circuitbreaker.CircuitBreaker instance to lookup and use from the registry. When using this, then any other circuit breaker options are not in use.		String
camel.resilience4j.config	Refers to an existing io.github.resilience4j.circuitbreaker.CircuitBreakerConfig instance to lookup and use from the registry.		String
camel.resilience4j.configurations	Define additional configuration definitions.		Map
camel.resilience4j.enabled	Enable the component.	true	Boolean
camel.resilience4j.failure-rate-threshold	Configures the failure rate threshold in percentage. If the failure rate is equal or greater than the threshold the CircuitBreaker transitions to open and starts short-circuiting calls. The threshold must be greater than 0 and not greater than 100. Default value is 50 percentage.		Float
camel.resilience4j.minimum-number-of-calls	Configures the minimum number of calls which are required (per sliding window period) before the CircuitBreaker can calculate the error rate. For example, if minimumNumberOfCalls is 10, then at least 10 calls must be recorded, before the failure rate can be calculated. If only 9 calls have been recorded the CircuitBreaker will not transition to open even if all 9 calls have failed. Default minimumNumberOfCalls is 100.	100	Integer
camel.resilience4j.permitted-number-of-calls-in-half-open-state	Configures the number of permitted calls when the CircuitBreaker is half open. The size must be greater than 0. Default size is 10.	10	Integer
camel.resilience4j.sliding-window-size	Configures the size of the sliding window which is used to record the outcome of calls when the CircuitBreaker is closed. slidingWindowSize configures the size of the sliding window. Sliding window can either be count-based or time-based. If slidingWindowType is COUNT_BASED, the last slidingWindowSize calls are recorded and aggregated. If slidingWindowType is TIME_BASED, the calls of the last slidingWindowSize seconds are recorded and aggregated. The slidingWindowSize must be greater than 0. The minimumNumberOfCalls must be greater than 0. If the slidingWindowType is COUNT_BASED, the minimumNumberOfCalls cannot be greater than slidingWindowSize . If the slidingWindowType is TIME_BASED, you can pick whatever you want. Default slidingWindowSize is 100.	100	Integer
camel.resilience4j.sliding-window-type	Configures the type of the sliding window which is used to record the outcome of calls when the CircuitBreaker is closed. Sliding window can either be count-based or time-based. If slidingWindowType is COUNT_BASED, the last slidingWindowSize calls are recorded and aggregated. If slidingWindowType is TIME_BASED, the calls of the last slidingWindowSize seconds are recorded and aggregated. Default slidingWindowType is COUNT_BASED.	COUNT_BASED	String
camel.resilience4j.slow-call-duration-threshold	Configures the duration threshold (seconds) above which calls are considered as slow and increase the slow calls percentage. Default value is 60 seconds.	60	Integer
camel.resilience4j.slow-call-rate-threshold	Configures a threshold in percentage. The CircuitBreaker considers a call as slow when the call duration is greater than slowCallDurationThreshold Duration. When the percentage of slow calls is equal or greater the threshold, the CircuitBreaker transitions to open and starts short-circuiting calls. The threshold must be greater than 0 and not greater than 100. Default value is 100 percentage which means that all recorded calls must be slower than slowCallDurationThreshold.		Float
camel.resilience4j.wait-duration-in-open-state	Configures the wait duration (in seconds) which specifies how long the CircuitBreaker should stay open, before it switches to half open. Default value is 60 seconds.	60	Integer
camel.resilience4j.writable-stack-trace-enabled	Enables writable stack traces. When set to false, Exception.getStackTrace returns a zero length array. This may be used to reduce log spam when the circuit breaker is open as the cause of the exceptions is already known (the circuit breaker is short-circuiting calls).	true	Boolean
camel.rest.api-component	The name of the Camel component to use as the REST API. If no API Component has been explicit configured, then Camel will lookup if there is a Camel component responsible for servicing and generating the REST API documentation, or if a org.apache.camel.spi.RestApiProcessorFactory is registered in the registry. If either one is found, then that is being used.		String
camel.rest.api-context-path	Sets a leading API context-path the REST API services will be using. This can be used when using components such as camel-servlet where the deployed web application is deployed using a context-path.		String
camel.rest.api-host	To use a specific hostname for the API documentation (such as swagger or openapi) This can be used to override the generated host with this configured hostname.		String
camel.rest.api-property	Allows to configure as many additional properties for the api documentation. For example set property api.title to my cool stuff.		Map
camel.rest.api-vendor-extension	Whether vendor extension is enabled in the Rest APIs. If enabled then Camel will include additional information as vendor extension (eg keys starting with x-) such as route ids, class names etc. Not all 3rd party API gateways and tools supports vendor-extensions when importing your API docs.	false	Boolean
camel.rest.binding-mode	Sets the binding mode to use. The default value is off.		RestBindingMode
camel.rest.client-request-validation	Whether to enable validation of the client request to check: 1) Content-Type header matches what the Rest DSL consumes; returns HTTP Status 415 if validation error. 2) Accept header matches what the Rest DSL produces; returns HTTP Status 406 if validation error. 3) Missing required data (query parameters, HTTP headers, body); returns HTTP Status 400 if validation error. 4) Parsing error of the message body (JSon, XML or Auto binding mode must be enabled); returns HTTP Status 400 if validation error.	false	Boolean
camel.rest.component	The Camel Rest component to use for the REST transport (consumer), such as netty-http, jetty, servlet, undertow. If no component has been explicit configured, then Camel will lookup if there is a Camel component that integrates with the Rest DSL, or if a org.apache.camel.spi.RestConsumerFactory is registered in the registry. If either one is found, then that is being used.		String
camel.rest.component-property	Allows to configure as many additional properties for the rest component in use.		Map
camel.rest.consumer-property	Allows to configure as many additional properties for the rest consumer in use.		Map
camel.rest.context-path	Sets a leading context-path the REST services will be using. This can be used when using components such as camel-servlet where the deployed web application is deployed using a context-path. Or for components such as camel-jetty or camel-netty-http that includes a HTTP server.		String
camel.rest.cors-headers	Allows to configure custom CORS headers.		Map
camel.rest.data-format-property	Allows to configure as many additional properties for the data formats in use. For example set property prettyPrint to true to have json outputted in pretty mode. The properties can be prefixed to denote the option is only for either JSON or XML and for either the IN or the OUT. The prefixes are: json.in. json.out. xml.in. xml.out. For example a key with value xml.out.mustBeJAXBElement is only for the XML data format for the outgoing. A key without a prefix is a common key for all situations.		Map
camel.rest.enable-cors	Whether to enable CORS headers in the HTTP response. The default value is false.	false	Boolean
camel.rest.endpoint-property	Allows to configure as many additional properties for the rest endpoint in use.		Map
camel.rest.host	The hostname to use for exposing the REST service.		String
camel.rest.host-name-resolver	If no hostname has been explicit configured, then this resolver is used to compute the hostname the REST service will be using.		RestHostNameResolver
camel.rest.json-data-format	Name of specific json data format to use. By default jackson will be used. Important: This option is only for setting a custom name of the data format, not to refer to an existing data format instance.		String
camel.rest.port	The port number to use for exposing the REST service. Notice if you use servlet component then the port number configured here does not apply, as the port number in use is the actual port number the servlet component is using. eg if using Apache Tomcat its the tomcat http port, if using Apache Karaf its the HTTP service in Karaf that uses port 8181 by default etc. Though in those situations setting the port number here, allows tooling and JMX to know the port number, so its recommended to set the port number to the number that the servlet engine uses.		String
camel.rest.producer-api-doc	Sets the location of the api document the REST producer will use to validate the REST uri and query parameters are valid accordingly to the api document. The location of the api document is loaded from classpath by default, but you can use file: or http: to refer to resources to load from file or http url.		String
camel.rest.producer-component	Sets the name of the Camel component to use as the REST producer.		String
camel.rest.scheme	The scheme to use for exposing the REST service. Usually http or https is supported. The default value is http.		String
camel.rest.skip-binding-on-error-code	Whether to skip binding on output if there is a custom HTTP error code header. This allows to build custom error messages that do not bind to json / xml etc, as success messages otherwise will do.	false	Boolean
camel.rest.use-x-forward-headers	Whether to use X-Forward headers for Host and related setting. The default value is true.	true	Boolean
camel.rest.xml-data-format	Name of specific XML data format to use. By default jaxb will be used. Important: This option is only for setting a custom name of the data format, not to refer to an existing data format instance.		String

Name

Description

Default

Type

camel.cloud.consul.service-discovery.acl-token

Sets the ACL token to be used with Consul.

String

camel.cloud.consul.service-discovery.block-seconds

The seconds to wait for a watch event, default 10 seconds.

Integer

camel.cloud.consul.service-discovery.configurations

Define additional configuration definitions.

Map

camel.cloud.consul.service-discovery.connect-timeout-millis

Connect timeout for OkHttpClient.

Long

camel.cloud.consul.service-discovery.datacenter

The data center.

String

camel.cloud.consul.service-discovery.enabled

Enable the component.

true

Boolean

camel.cloud.consul.service-discovery.password

Sets the password to be used for basic authentication.

String

camel.cloud.consul.service-discovery.properties

Set client properties to use. These properties are specific to what service call implementation are in use. For example if using ribbon, then the client properties are define in com.netflix.client.config.CommonClientConfigKey.

Map

camel.cloud.consul.service-discovery.read-timeout-millis

Read timeout for OkHttpClient.

Long

camel.cloud.consul.service-discovery.url

The Consul agent URL.

String

camel.cloud.consul.service-discovery.user-name

Sets the username to be used for basic authentication.

String

camel.cloud.consul.service-discovery.write-timeout-millis

Write timeout for OkHttpClient.

Long

camel.cloud.dns.service-discovery.configurations

Define additional configuration definitions.

Map

camel.cloud.dns.service-discovery.domain

The domain name;.

String

camel.cloud.dns.service-discovery.enabled

Enable the component.

true

Boolean

camel.cloud.dns.service-discovery.properties

Map

camel.cloud.dns.service-discovery.proto

The transport protocol of the desired service.

_tcp

String

camel.cloud.etcd.service-discovery.configurations

Define additional configuration definitions.

Map

camel.cloud.etcd.service-discovery.enabled

Enable the component.

true

Boolean

camel.cloud.etcd.service-discovery.password

The password to use for basic authentication.

String

camel.cloud.etcd.service-discovery.properties

Map

camel.cloud.etcd.service-discovery.service-path

The path to look for for service discovery.

/services/

String

camel.cloud.etcd.service-discovery.timeout

To set the maximum time an action could take to complete.

Long

camel.cloud.etcd.service-discovery.type

To set the discovery type, valid values are on-demand and watch.

on-demand

String

camel.cloud.etcd.service-discovery.uris

The URIs the client can connect to.

String

camel.cloud.etcd.service-discovery.user-name

The user name to use for basic authentication.

String

camel.cloud.kubernetes.service-discovery.api-version

Sets the API version when using client lookup.

String

camel.cloud.kubernetes.service-discovery.ca-cert-data

Sets the Certificate Authority data when using client lookup.

String

camel.cloud.kubernetes.service-discovery.ca-cert-file

Sets the Certificate Authority data that are loaded from the file when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-cert-data

Sets the Client Certificate data when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-cert-file

Sets the Client Certificate data that are loaded from the file when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-key-algo

Sets the Client Keystore algorithm, such as RSA when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-key-data

Sets the Client Keystore data when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-key-file

Sets the Client Keystore data that are loaded from the file when using client lookup.

String

camel.cloud.kubernetes.service-discovery.client-key-passphrase

Sets the Client Keystore passphrase when using client lookup.

String

camel.cloud.kubernetes.service-discovery.configurations

Define additional configuration definitions.

Map

camel.cloud.kubernetes.service-discovery.dns-domain

Sets the DNS domain to use for DNS lookup.

String

camel.cloud.kubernetes.service-discovery.enabled

Enable the component.

true

Boolean

camel.cloud.kubernetes.service-discovery.lookup

How to perform service lookup. Possible values: client, dns, environment. When using client, then the client queries the kubernetes master to obtain a list of active pods that provides the service, and then random (or round robin) select a pod. When using dns the service name is resolved as name.namespace.svc.dnsDomain. When using dnssrv the service name is resolved with SRV query for .…svc… When using environment then environment variables are used to lookup the service. By default environment is used.

environment

String

camel.cloud.kubernetes.service-discovery.master-url

Sets the URL to the master when using client lookup.

String

camel.cloud.kubernetes.service-discovery.namespace

Sets the namespace to use. Will by default use namespace from the ENV variable KUBERNETES_MASTER.

String

camel.cloud.kubernetes.service-discovery.oauth-token

Sets the OAUTH token for authentication (instead of username/password) when using client lookup.

String

camel.cloud.kubernetes.service-discovery.password

Sets the password for authentication when using client lookup.

String

camel.cloud.kubernetes.service-discovery.port-name

Sets the Port Name to use for DNS/DNSSRV lookup.

String

camel.cloud.kubernetes.service-discovery.port-protocol

Sets the Port Protocol to use for DNS/DNSSRV lookup.

String

camel.cloud.kubernetes.service-discovery.properties

Map

camel.cloud.kubernetes.service-discovery.trust-certs

Sets whether to turn on trust certificate check when using client lookup.

false

Boolean

camel.cloud.kubernetes.service-discovery.username

Sets the username for authentication when using client lookup.

String

camel.cloud.ribbon.load-balancer.client-name

Sets the Ribbon client name.

String

camel.cloud.ribbon.load-balancer.configurations

Define additional configuration definitions.

Map

camel.cloud.ribbon.load-balancer.enabled

Enable the component.

true

Boolean

camel.cloud.ribbon.load-balancer.namespace

The namespace.

String

camel.cloud.ribbon.load-balancer.password

The password.

String

camel.cloud.ribbon.load-balancer.properties

Map

camel.cloud.ribbon.load-balancer.username

The username.

String

camel.hystrix.allow-maximum-size-to-diverge-from-core-size

Allows the configuration for maximumSize to take effect. That value can then be equal to, or higher, than coreSize.

false

Boolean

camel.hystrix.circuit-breaker-enabled

Whether to use a HystrixCircuitBreaker or not. If false no circuit-breaker logic will be used and all requests permitted. This is similar in effect to circuitBreakerForceClosed() except that continues tracking metrics and knowing whether it should be open/closed, this property results in not even instantiating a circuit-breaker.

true

Boolean

camel.hystrix.circuit-breaker-error-threshold-percentage

Error percentage threshold (as whole number such as 50) at which point the circuit breaker will trip open and reject requests. It will stay tripped for the duration defined in circuitBreakerSleepWindowInMilliseconds; The error percentage this is compared against comes from HystrixCommandMetrics.getHealthCounts().

Integer

camel.hystrix.circuit-breaker-force-closed

If true the HystrixCircuitBreaker#allowRequest() will always return true to allow requests regardless of the error percentage from HystrixCommandMetrics.getHealthCounts(). The circuitBreakerForceOpen() property takes precedence so if it set to true this property does nothing.

false

Boolean

camel.hystrix.circuit-breaker-force-open

If true the HystrixCircuitBreaker.allowRequest() will always return false, causing the circuit to be open (tripped) and reject all requests. This property takes precedence over circuitBreakerForceClosed();.

false

Boolean

camel.hystrix.circuit-breaker-request-volume-threshold

Minimum number of requests in the metricsRollingStatisticalWindowInMilliseconds() that must exist before the HystrixCircuitBreaker will trip. If below this number the circuit will not trip regardless of error percentage.

Integer

camel.hystrix.circuit-breaker-sleep-window-in-milliseconds

The time in milliseconds after a HystrixCircuitBreaker trips open that it should wait before trying requests again.

5000

Integer

camel.hystrix.configurations

Define additional configuration definitions.

Map

camel.hystrix.core-pool-size

Core thread-pool size that gets passed to java.util.concurrent.ThreadPoolExecutor#setCorePoolSize(int).

Integer

camel.hystrix.enabled

Enable the component.

true

Boolean

camel.hystrix.execution-isolation-semaphore-max-concurrent-requests

Number of concurrent requests permitted to HystrixCommand.run(). Requests beyond the concurrent limit will be rejected. Applicable only when executionIsolationStrategy == SEMAPHORE.

Integer

camel.hystrix.execution-isolation-strategy

What isolation strategy HystrixCommand.run() will be executed with. If THREAD then it will be executed on a separate thread and concurrent requests limited by the number of threads in the thread-pool. If SEMAPHORE then it will be executed on the calling thread and concurrent requests limited by the semaphore count.

THREAD

String

camel.hystrix.execution-isolation-thread-interrupt-on-timeout

Whether the execution thread should attempt an interrupt (using Future#cancel ) when a thread times out. Applicable only when executionIsolationStrategy() == THREAD.

true

Boolean

camel.hystrix.execution-timeout-enabled

Whether the timeout mechanism is enabled for this command.

true

Boolean

camel.hystrix.execution-timeout-in-milliseconds

Time in milliseconds at which point the command will timeout and halt execution. If executionIsolationThreadInterruptOnTimeout == true and the command is thread-isolated, the executing thread will be interrupted. If the command is semaphore-isolated and a HystrixObservableCommand, that command will get unsubscribed.

1000

Integer

camel.hystrix.fallback-enabled

Whether HystrixCommand.getFallback() should be attempted when failure occurs.

true

Boolean

camel.hystrix.fallback-isolation-semaphore-max-concurrent-requests

Number of concurrent requests permitted to HystrixCommand.getFallback(). Requests beyond the concurrent limit will fail-fast and not attempt retrieving a fallback.

Integer

camel.hystrix.group-key

Sets the group key to use. The default value is CamelHystrix.

CamelHystrix

String

camel.hystrix.keep-alive-time

Keep-alive time in minutes that gets passed to ThreadPoolExecutor#setKeepAliveTime(long,TimeUnit).

Integer

camel.hystrix.max-queue-size

Max queue size that gets passed to BlockingQueue in HystrixConcurrencyStrategy.getBlockingQueue(int) This should only affect the instantiation of a threadpool - it is not eliglible to change a queue size on the fly. For that, use queueSizeRejectionThreshold().

-1

Integer

camel.hystrix.maximum-size

Maximum thread-pool size that gets passed to ThreadPoolExecutor#setMaximumPoolSize(int) . This is the maximum amount of concurrency that can be supported without starting to reject HystrixCommands. Please note that this setting only takes effect if you also set allowMaximumSizeToDivergeFromCoreSize.

Integer

camel.hystrix.metrics-health-snapshot-interval-in-milliseconds

Time in milliseconds to wait between allowing health snapshots to be taken that calculate success and error percentages and affect HystrixCircuitBreaker.isOpen() status. On high-volume circuits the continual calculation of error percentage can become CPU intensive thus this controls how often it is calculated.

500

Integer

camel.hystrix.metrics-rolling-percentile-bucket-size

Maximum number of values stored in each bucket of the rolling percentile. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

Integer

camel.hystrix.metrics-rolling-percentile-enabled

Whether percentile metrics should be captured using HystrixRollingPercentile inside HystrixCommandMetrics.

true

Boolean

camel.hystrix.metrics-rolling-percentile-window-buckets

Number of buckets the rolling percentile window is broken into. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

Integer

camel.hystrix.metrics-rolling-percentile-window-in-milliseconds

Duration of percentile rolling window in milliseconds. This is passed into HystrixRollingPercentile inside HystrixCommandMetrics.

10000

Integer

camel.hystrix.metrics-rolling-statistical-window-buckets

Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside HystrixCommandMetrics.

Integer

camel.hystrix.metrics-rolling-statistical-window-in-milliseconds

This property sets the duration of the statistical rolling window, in milliseconds. This is how long metrics are kept for the thread pool. The window is divided into buckets and rolls by those increments.

10000

Integer

camel.hystrix.queue-size-rejection-threshold

Queue size rejection threshold is an artificial max size at which rejections will occur even if maxQueueSize has not been reached. This is done because the maxQueueSize of a BlockingQueue can not be dynamically changed and we want to support dynamically changing the queue size that affects rejections. This is used by HystrixCommand when queuing a thread for execution.

Integer

camel.hystrix.request-log-enabled

Whether HystrixCommand execution and events should be logged to HystrixRequestLog.

true

Boolean

camel.hystrix.thread-pool-key

Sets the thread pool key to use. Will by default use the same value as groupKey has been configured to use.

CamelHystrix

String

camel.hystrix.thread-pool-rolling-number-statistical-window-buckets

Number of buckets the rolling statistical window is broken into. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.

Integer

camel.hystrix.thread-pool-rolling-number-statistical-window-in-milliseconds

Duration of statistical rolling window in milliseconds. This is passed into HystrixRollingNumber inside each HystrixThreadPoolMetrics instance.

10000

Integer

camel.language.constant.enabled

Whether to enable auto configuration of the constant language. This is enabled by default.

Boolean

camel.language.constant.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.csimple.enabled

Whether to enable auto configuration of the csimple language. This is enabled by default.

Boolean

camel.language.csimple.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.exchange-property.enabled

Whether to enable auto configuration of the exchangeProperty language. This is enabled by default.

Boolean

camel.language.exchange-property.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.file.enabled

Whether to enable auto configuration of the file language. This is enabled by default.

Boolean

camel.language.file.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.header.enabled

Whether to enable auto configuration of the header language. This is enabled by default.

Boolean

camel.language.header.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.ref.enabled

Whether to enable auto configuration of the ref language. This is enabled by default.

Boolean

camel.language.ref.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.simple.enabled

Whether to enable auto configuration of the simple language. This is enabled by default.

Boolean

camel.language.simple.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.language.tokenize.enabled

Whether to enable auto configuration of the tokenize language. This is enabled by default.

Boolean

camel.language.tokenize.group-delimiter

Sets the delimiter to use when grouping. If this has not been set then token will be used as the delimiter.

String

camel.language.tokenize.trim

Whether to trim the value to remove leading and trailing whitespaces and line breaks.

true

Boolean

camel.resilience4j.automatic-transition-from-open-to-half-open-enabled

Enables automatic transition from OPEN to HALF_OPEN state once the waitDurationInOpenState has passed.

false

Boolean

camel.resilience4j.circuit-breaker

Refers to an existing io.github.resilience4j.circuitbreaker.CircuitBreaker instance to lookup and use from the registry. When using this, then any other circuit breaker options are not in use.

String

camel.resilience4j.config

Refers to an existing io.github.resilience4j.circuitbreaker.CircuitBreakerConfig instance to lookup and use from the registry.

String

camel.resilience4j.configurations

Define additional configuration definitions.

Map

camel.resilience4j.enabled

Enable the component.

true

Boolean

camel.resilience4j.failure-rate-threshold

Configures the failure rate threshold in percentage. If the failure rate is equal or greater than the threshold the CircuitBreaker transitions to open and starts short-circuiting calls. The threshold must be greater than 0 and not greater than 100. Default value is 50 percentage.

Float

camel.resilience4j.minimum-number-of-calls

Configures the minimum number of calls which are required (per sliding window period) before the CircuitBreaker can calculate the error rate. For example, if minimumNumberOfCalls is 10, then at least 10 calls must be recorded, before the failure rate can be calculated. If only 9 calls have been recorded the CircuitBreaker will not transition to open even if all 9 calls have failed. Default minimumNumberOfCalls is 100.

100

Integer

camel.resilience4j.permitted-number-of-calls-in-half-open-state

Configures the number of permitted calls when the CircuitBreaker is half open. The size must be greater than 0. Default size is 10.

Integer

camel.resilience4j.sliding-window-size

Configures the size of the sliding window which is used to record the outcome of calls when the CircuitBreaker is closed. slidingWindowSize configures the size of the sliding window. Sliding window can either be count-based or time-based. If slidingWindowType is COUNT_BASED, the last slidingWindowSize calls are recorded and aggregated. If slidingWindowType is TIME_BASED, the calls of the last slidingWindowSize seconds are recorded and aggregated. The slidingWindowSize must be greater than 0. The minimumNumberOfCalls must be greater than 0. If the slidingWindowType is COUNT_BASED, the minimumNumberOfCalls cannot be greater than slidingWindowSize . If the slidingWindowType is TIME_BASED, you can pick whatever you want. Default slidingWindowSize is 100.

100

Integer

camel.resilience4j.sliding-window-type

Configures the type of the sliding window which is used to record the outcome of calls when the CircuitBreaker is closed. Sliding window can either be count-based or time-based. If slidingWindowType is COUNT_BASED, the last slidingWindowSize calls are recorded and aggregated. If slidingWindowType is TIME_BASED, the calls of the last slidingWindowSize seconds are recorded and aggregated. Default slidingWindowType is COUNT_BASED.

COUNT_BASED

String

camel.resilience4j.slow-call-duration-threshold

Configures the duration threshold (seconds) above which calls are considered as slow and increase the slow calls percentage. Default value is 60 seconds.

Integer

camel.resilience4j.slow-call-rate-threshold

Configures a threshold in percentage. The CircuitBreaker considers a call as slow when the call duration is greater than slowCallDurationThreshold Duration. When the percentage of slow calls is equal or greater the threshold, the CircuitBreaker transitions to open and starts short-circuiting calls. The threshold must be greater than 0 and not greater than 100. Default value is 100 percentage which means that all recorded calls must be slower than slowCallDurationThreshold.

Float

camel.resilience4j.wait-duration-in-open-state

Configures the wait duration (in seconds) which specifies how long the CircuitBreaker should stay open, before it switches to half open. Default value is 60 seconds.

Integer

camel.resilience4j.writable-stack-trace-enabled

Enables writable stack traces. When set to false, Exception.getStackTrace returns a zero length array. This may be used to reduce log spam when the circuit breaker is open as the cause of the exceptions is already known (the circuit breaker is short-circuiting calls).

true

Boolean

camel.rest.api-component

The name of the Camel component to use as the REST API. If no API Component has been explicit configured, then Camel will lookup if there is a Camel component responsible for servicing and generating the REST API documentation, or if a org.apache.camel.spi.RestApiProcessorFactory is registered in the registry. If either one is found, then that is being used.

String

camel.rest.api-context-path

Sets a leading API context-path the REST API services will be using. This can be used when using components such as camel-servlet where the deployed web application is deployed using a context-path.

String

camel.rest.api-host

To use a specific hostname for the API documentation (such as swagger or openapi) This can be used to override the generated host with this configured hostname.

String

camel.rest.api-property

Allows to configure as many additional properties for the api documentation. For example set property api.title to my cool stuff.

Map

camel.rest.api-vendor-extension

Whether vendor extension is enabled in the Rest APIs. If enabled then Camel will include additional information as vendor extension (eg keys starting with x-) such as route ids, class names etc. Not all 3rd party API gateways and tools supports vendor-extensions when importing your API docs.

false

Boolean

camel.rest.binding-mode

Sets the binding mode to use. The default value is off.

RestBindingMode

camel.rest.client-request-validation

Whether to enable validation of the client request to check: 1) Content-Type header matches what the Rest DSL consumes; returns HTTP Status 415 if validation error. 2) Accept header matches what the Rest DSL produces; returns HTTP Status 406 if validation error. 3) Missing required data (query parameters, HTTP headers, body); returns HTTP Status 400 if validation error. 4) Parsing error of the message body (JSon, XML or Auto binding mode must be enabled); returns HTTP Status 400 if validation error.

false

Boolean

camel.rest.component

The Camel Rest component to use for the REST transport (consumer), such as netty-http, jetty, servlet, undertow. If no component has been explicit configured, then Camel will lookup if there is a Camel component that integrates with the Rest DSL, or if a org.apache.camel.spi.RestConsumerFactory is registered in the registry. If either one is found, then that is being used.

String

camel.rest.component-property

Allows to configure as many additional properties for the rest component in use.

Map

camel.rest.consumer-property

Allows to configure as many additional properties for the rest consumer in use.

Map

camel.rest.context-path

Sets a leading context-path the REST services will be using. This can be used when using components such as camel-servlet where the deployed web application is deployed using a context-path. Or for components such as camel-jetty or camel-netty-http that includes a HTTP server.

String

camel.rest.cors-headers

Allows to configure custom CORS headers.

Map

camel.rest.data-format-property

Allows to configure as many additional properties for the data formats in use. For example set property prettyPrint to true to have json outputted in pretty mode. The properties can be prefixed to denote the option is only for either JSON or XML and for either the IN or the OUT. The prefixes are: json.in. json.out. xml.in. xml.out. For example a key with value xml.out.mustBeJAXBElement is only for the XML data format for the outgoing. A key without a prefix is a common key for all situations.

Map

camel.rest.enable-cors

Whether to enable CORS headers in the HTTP response. The default value is false.

false

Boolean

camel.rest.endpoint-property

Allows to configure as many additional properties for the rest endpoint in use.

Map

camel.rest.host

The hostname to use for exposing the REST service.

String

camel.rest.host-name-resolver

If no hostname has been explicit configured, then this resolver is used to compute the hostname the REST service will be using.

RestHostNameResolver

camel.rest.json-data-format

Name of specific json data format to use. By default jackson will be used. Important: This option is only for setting a custom name of the data format, not to refer to an existing data format instance.

String

camel.rest.port

The port number to use for exposing the REST service. Notice if you use servlet component then the port number configured here does not apply, as the port number in use is the actual port number the servlet component is using. eg if using Apache Tomcat its the tomcat http port, if using Apache Karaf its the HTTP service in Karaf that uses port 8181 by default etc. Though in those situations setting the port number here, allows tooling and JMX to know the port number, so its recommended to set the port number to the number that the servlet engine uses.

String

camel.rest.producer-api-doc

Sets the location of the api document the REST producer will use to validate the REST uri and query parameters are valid accordingly to the api document. The location of the api document is loaded from classpath by default, but you can use file: or http: to refer to resources to load from file or http url.

String

camel.rest.producer-component

Sets the name of the Camel component to use as the REST producer.

String

camel.rest.scheme

The scheme to use for exposing the REST service. Usually http or https is supported. The default value is http.

String

camel.rest.skip-binding-on-error-code

Whether to skip binding on output if there is a custom HTTP error code header. This allows to build custom error messages that do not bind to json / xml etc, as success messages otherwise will do.

false

Boolean

camel.rest.use-x-forward-headers

Whether to use X-Forward headers for Host and related setting. The default value is true.

true

Boolean

camel.rest.xml-data-format

Name of specific XML data format to use. By default jaxb will be used. Important: This option is only for setting a custom name of the data format, not to refer to an existing data format instance.

String