Chapter 67. CSimple

The CSimple language is compiled Simple language.

67.1. Different between CSimple and Simple

The simple language is a dynamic expression language which is runtime parsed into a set of Camel Expressions or Predicates.

The csimple language is parsed into regular Java source code and compiled together with all the other source code, or compiled once during bootstrap via the camel-csimple-joor module.

The simple language is generally very lightweight and fast, however for some use-cases with dynamic method calls via OGNL paths, then the simple language does runtime introspection and reflection calls. This has an overhead on performance, and was one of the reasons why csimple was created.

The csimple language requires to be typesafe and method calls via OGNL paths requires to know the type during parsing. This means for csimple languages expressions you would need to provide the class type in the script, whereas simple introspects this at runtime.

In other words the simple language is using duck typing (if it looks like a duck, and quacks like a duck, then it is a duck) and csimple is using Java type (typesafety). If there is a type error then simple will report this at runtime, and with csimple there will be a Java compilation error.

67.1.1. Additional CSimple functions

The csimple language includes some additional functions to support common use-cases working with Collection, Map or array types. The following functions bodyAsIndex, headerAsIndex, and exchangePropertyAsIndex is used for these use-cases as they are typed.

FunctionTypeDescription

bodyAsIndex(type, index)

Type

To be used for collecting the body from an existing Collection, Map or array (lookup by the index) and then converting the body to the given type determined by its classname. The converted body can be null.

mandatoryBodyAsIndex(type, index)

Type

To be used for collecting the body from an existing Collection, Map or array (lookup by the index) and then converting the body to the given type determined by its classname. Expects the body to be not null.

headerAsIndex(key, type, index)

Type

To be used for collecting a header from an existing Collection, Map or array (lookup by the index) and then converting the header value to the given type determined by its classname. The converted header can be null.

mandatoryHeaderAsIndex(key, type, index)

Type

To be used for collecting a header from an existing Collection, Map or array (lookup by the index) and then converting the header value to the given type determined by its classname. Expects the header to be not null.

exchangePropertyAsIndex(key, type, index)

Type

To be used for collecting an exchange property from an existing Collection, Map or array (lookup by the index) and then converting the exchange property to the given type determined by its classname. The converted exchange property can be null.

mandatoryExchangePropertyAsIndex(key, type, index)

Type

To be used for collecting an exchange property from an existing Collection, Map or array (lookup by the index) and then converting the exchange property to the given type determined by its classname. Expects the exchange property to be not null.

For example given the following simple expression: 

Hello $\{body[0].name}

This script has no type information, and the simple language will resolve this at runtime, by introspecting the message body and if it’s a collection based then lookup the first element, and then invoke a method named getName via reflection.

In csimple (compiled) we want to pre compile this and therefore the end user must provide type information with the bodyAsIndex function: 

Hello $\{bodyAsIndex(com.foo.MyUser, 0).name}

67.2. Compilation

The csimple language is parsed into regular Java source code and compiled together with all the other source code, or it can be compiled once during bootstrap via the camel-csimple-joor module.

There are two ways to compile csimple

  • using the camel-csimple-maven-plugin generating source code at built time.
  • using camel-csimple-joor which does runtime in-memory compilation during bootstrap of Camel.

67.2.1. Using camel-csimple-maven-plugin

The camel-csimple-maven-plugin Maven plugin is used for discovering all the csimple scripts from the source code, and then automatic generate source code in the src/generated/java folder, which then gets compiled together with all the other sources.

The maven plugin will do source code scanning of .java and .xml files (Java and XML DSL). The scanner limits to detect certain code patterns, and it may miss discovering some csimple scripts if they are being used in unusual/rare ways.

The runtime compilation using camel-csimple-joor does not have this limitation.

The benefit is all the csimple scripts will be compiled using the regular Java compiler and therefore everything is included out of the box as .class files in the application JAR file, and no additional dependencies is required at runtime.

To use camel-csimple-maven-plugin you need to add it to your pom.xml file as shown: 

<plugins>
    <!-- generate source code for csimple languages -->
    <plugin>
        <groupId>org.apache.camel</groupId>
        <artifactId>camel-csimple-maven-plugin</artifactId>
        <version>${camel.version}</version>
        <executions>
            <execution>
                <id>generate</id>
                <goals>
                    <goal>generate</goal>
                </goals>
            </execution>
        </executions>
    </plugin>
    <!-- include source code generated to maven sources paths -->
    <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>build-helper-maven-plugin</artifactId>
        <version>3.1.0</version>
        <executions>
            <execution>
                <phase>generate-sources</phase>
                <goals>
                    <goal>add-source</goal>
                    <goal>add-resource</goal>
                </goals>
                <configuration>
                    <sources>
                        <source>src/generated/java</source>
                    </sources>
                    <resources>
                        <resource>
                            <directory>src/generated/resources</directory>
                        </resource>
                    </resources>
                </configuration>
            </execution>
        </executions>
    </plugin>
</plugins>

And then you must also add the build-helper-maven-plugin Maven plugin to include src/generated to the list of source folders for the Java compiler, to ensure the generated source code is compiled and included in the application JAR file.

See the camel-example-csimple example at Camel Examples which uses the maven plugin.

67.2.2. Using camel-csimple-joor

The jOOR library integrates with the Java compiler and performs runtime compilation of Java code.

The supported runtime when using camel-simple-joor is intended for Java standalone, Spring Boot, Camel Quarkus and other microservices runtimes. It is not supported in OSGi, Camel Karaf or any kind of Java Application Server runtime.

jOOR does not support runtime compilation with Spring Boot using fat jar packaging (https://github.com/jOOQ/jOOR/issues/69), it works with exploded classpath.

To use camel-simple-joor you simply just add it as dependency to the classpath: 

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-csimple-joor</artifactId>
  <version>3.14.5.redhat-00032</version>
</dependency>

There is no need for adding Maven plugins to the pom.xml file.

See the camel-example-csimple-joor example at Camel Examples which uses the jOOR compiler.

67.3. CSimple Language options

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

NameDefaultJava TypeDescription

resultType

 

String

Sets the class name of the result type (type from output).

trim

 

Boolean

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

67.4. Limitations

Currently, the csimple language does not support:

  • nested functions (aka functions inside functions)
  • the null safe operator (?).

For example the following scripts cannot compile: 

  Hello ${bean:greeter(${body}, ${header.counter})}
  ${bodyAs(MyUser)?.address?.zip} > 10000

67.5. Auto imports

The csimple language will automatically import from: 

import java.util.*;
import java.util.concurrent.*;
import java.util.stream.*;
import org.apache.camel.*;
import org.apache.camel.util.*;

67.6. Configuration file

You can configure the csimple language in the camel-csimple.properties file which is loaded from the root classpath.

For example you can add additional imports in the camel-csimple.properties file by adding: 

import com.foo.MyUser;
import com.bar.*;
import static com.foo.MyHelper.*;

You can also add aliases (key=value) where an alias will be used as a shorthand replacement in the code. 

echo()=${bodyAs(String)} ${bodyAs(String)}

Which allows to use echo() in the csimple language script such as: 

from("direct:hello")
    .transform(csimple("Hello echo()"))
    .log("You said ${body}");

The echo() alias will be replaced with its value resulting in a script as: 

    .transform(csimple("Hello ${bodyAs(String)} ${bodyAs(String)}"))

67.7. See Also

See the Simple language as csimple has the same set of functions as simple language.

67.8. Spring Boot Auto-Configuration

When using csimple 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>3.14.5.redhat-00032</version>
  <!-- Use your Camel Spring Boot version -->
</dependency>

The component supports 147 options, which are listed below.

NameDescriptionDefaultType

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.exchangeproperty.enabled

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

 

Boolean

camel.language.exchangeproperty.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-ref

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-ref

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 (such as swagger) 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-context-route-id

Sets the route id to use for the route that services the REST API. The route will by default use an auto assigned route id.

 

String

camel.rest.api-host

To use an specific hostname for the API documentation (eg swagger) 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 (swagger). 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 whether the Content-Type and Accept headers from the client is supported by the Rest-DSL configuration of its consumes/produces settings. This can be turned on, to enable this check. In case of validation error, then HTTP Status codes 415 or 406 is returned. The default value is false.

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 json-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 (swagger api) the REST producer will use to validate the REST uri and query parameters are valid accordingly to the api document. This requires adding camel-swagger-java to the classpath, and any miss configuration will let Camel fail on startup and report the error(s). 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

camel.rest.api-context-id-pattern

Deprecated Sets an CamelContext id pattern to only allow Rest APIs from rest services within CamelContext’s which name matches the pattern. The pattern name refers to the CamelContext name, to match on the current CamelContext only. For any other value, the pattern uses the rules from PatternHelper#matchPattern(String,String).

 

String

camel.rest.api-context-listing

Deprecated Sets whether listing of all available CamelContext’s with REST services in the JVM is enabled. If enabled it allows to discover these contexts, if false then only the current CamelContext is in use.

false

Boolean