Chapter 92. Simple
The Simple Expression Language was a really simple language when it was created, but has since grown more powerful. It is primarily intended for being a very small and simple language for evaluating Expression
or Predicate
without requiring any new dependencies or knowledge of other scripting languages such as Groovy.
The simple language is designed with intend to cover almost all the common use cases when little need for scripting in your Camel routes.
However, for much more complex use cases then a more powerful language is recommended such as:
The simple language requires camel-bean
JAR as classpath dependency if the simple language uses OGNL expressions, such as calling a method named myMethod
on the message body: ${body.myMethod()}
. At runtime the simple language will then us its built-in OGNL support which requires the camel-bean
component.
The simple language uses ${body}
placeholders for complex expressions or functions.
See also the CSimple language which is compiled.
Alternative syntax
You can also use the alternative syntax which uses $simple{ }
as placeholders. This can be used in situations to avoid clashes when using for example Spring property placeholder together with Camel.
92.1. Simple Language options
The Simple language supports 2 options, which are listed below.
Name | Default | Java Type | Description |
---|---|---|---|
resultType |
| Sets the class name of the result type (type from output). | |
trim |
| Whether to trim the value to remove leading and trailing whitespaces and line breaks. |
92.2. Variables
Variable | Type | Description |
---|---|---|
camelId | String | the CamelContext name |
camelContext.OGNL | Object | the CamelContext invoked using a Camel OGNL expression. |
exchange | Exchange | the Exchange |
exchange.OGNL | Object | the Exchange invoked using a Camel OGNL expression. |
exchangeId | String | the exchange id |
id | String | the message id |
messageTimestamp | String | the message timestamp (millis since epoc) that this message originates from. Some systems like JMS, Kafka, AWS have a timestamp on the event/message, that Camel received. This method returns the timestamp, if a timestamp exists. The message timestamp and exchange created are not the same. An exchange always have a created timestamp which is the local timestamp when Camel created the exchange. The message timestamp is only available in some Camel components when the consumer is able to extract the timestamp from the source event. If the message has no timestamp then 0 is returned. |
body | Object | the body |
body.OGNL | Object | the body invoked using a Camel OGNL expression. |
bodyAs(type) | Type | Converts the body to the given type determined by its classname. The converted body can be null. |
bodyAs(type).OGNL | Object | Converts the body to the given type determined by its classname and then invoke methods using a Camel OGNL expression. The converted body can be null. |
bodyOneLine | String | Converts the body to a String and removes all line-breaks so the string is in one line. |
mandatoryBodyAs(type) | Type | Converts the body to the given type determined by its classname, and expects the body to be not null. |
mandatoryBodyAs(type).OGNL | Object | Converts the body to the given type determined by its classname and then invoke methods using a Camel OGNL expression. |
header.foo | Object | refer to the foo header |
header[foo] | Object | refer to the foo header |
headers.foo | Object | refer to the foo header |
headers:foo | Object | refer to the foo header |
headers[foo] | Object | refer to the foo header |
header.foo[bar] | Object | regard foo header as a map and perform lookup on the map with bar as key |
header.foo.OGNL | Object | refer to the foo header and invoke its value using a Camel OGNL expression. |
headerAs(key,type) | Type | converts the header to the given type determined by its classname |
headers | Map | refer to the headers |
exchangeProperty.foo | Object | refer to the foo property on the exchange |
exchangeProperty[foo] | Object | refer to the foo property on the exchange |
exchangeProperty.foo.OGNL | Object | refer to the foo property on the exchange and invoke its value using a Camel OGNL expression. |
sys.foo | String | refer to the JVM system property |
sysenv.foo | String | refer to the system environment variable |
env.foo | String | refer to the system environment variable |
exception | Object |
refer to the exception object on the exchange, is null if no exception set on exchange. Will fallback and grab caught exceptions ( |
exception.OGNL | Object | refer to the exchange exception invoked using a Camel OGNL expression object |
exception.message | String |
refer to the exception.message on the exchange, is null if no exception set on exchange. Will fallback and grab caught exceptions ( |
exception.stacktrace | String |
refer to the exception.stracktrace on the exchange, is null if no exception set on exchange. Will fallback and grab caught exceptions ( |
date:_command_ | Date | evaluates to a Date object. Supported commands are: now for current timestamp, exchangeCreated for the timestamp when the current exchange was created, header.xxx to use the Long/Date object header with the key xxx. exchangeProperty.xxx to use the Long/Date object in the exchange property with the key xxx. file for the last modified timestamp of the file (available with a File consumer). Command accepts offsets such as: now-24h or header.xxx+1h or even now+1h30m-100. |
date:_command:pattern_ | String |
Date formatting using |
date-with-timezone:_command:timezone:pattern_ | String |
Date formatting using |
bean:_bean expression_ | Object |
Invoking a bean expression using the language. Specifying a method name you must use dot as separator. We also support the ?method=methodname syntax that is used by the component. Camel will by default lookup a bean by the given name. However if you need to refer to a bean class (such as calling a static method) then you can prefix with type, such as |
| String | Lookup a property with the given key. If the key does not exists or has no value, then an optional default value can be specified. |
routeId | String | Returns the id of the current route the Exchange is being routed. |
stepId | String | Returns the id of the current step the Exchange is being routed. |
threadName | String | Returns the name of the current thread. Can be used for logging purpose. |
hostname | String | Returns the local hostname (may be empty if not possible to resolve). |
ref:xxx | Object | To lookup a bean from the Registry with the given id. |
type:name.field | Object |
To refer to a type or field by its FQN name. To refer to a field you can append .FIELD_NAME. For example, you can refer to the constant field from Exchange as: |
null | null | represents a null |
random(value) | Integer | returns a random Integer between 0 (included) and value (excluded) |
random(min,max) | Integer | returns a random Integer between min (included) and max (excluded) |
collate(group) | List | The collate function iterates the message body and groups the data into sub lists of specified size. This can be used with the Splitter EIP to split a message body and group/batch the splitted sub message into a group of N sub lists. This method works similar to the collate method in Groovy. |
skip(number) | Iterator | The skip function iterates the message body and skips the first number of items. This can be used with the Splitter EIP to split a message body and skip the first N number of items. |
messageHistory | String | The message history of the current exchange how it has been routed. This is similar to the route stack-trace message history the error handler logs in case of an unhandled exception. |
messageHistory(false) | String | As messageHistory but without the exchange details (only includes the route stack-trace). This can be used if you do not want to log sensitive data from the message itself. |
92.3. OGNL expression support
When using OGNL then camel-bean
JAR is required to be on the classpath.
Camel’s OGNL support is for invoking methods only. You cannot access fields. Camel support accessing the length field of Java arrays.
The Simple and Bean language now supports a Camel OGNL notation for invoking beans in a chain like fashion. Suppose the Message IN body contains a POJO which has a getAddress()
method.
Then you can use Camel OGNL notation to access the address object:
simple("${body.address}") simple("${body.address.street}") simple("${body.address.zip}")
Camel understands the shorthand names for getters, but you can invoke any method or use the real name such as:
simple("${body.address}") simple("${body.getAddress.getStreet}") simple("${body.address.getZip}") simple("${body.doSomething}")
You can also use the null safe operator (?.
) to avoid NPE if for example the body does NOT have an address
simple("${body?.address?.street}")
It is also possible to index in Map
or List
types, so you can do:
simple("${body[foo].name}")
To assume the body is Map
based and lookup the value with foo
as key, and invoke the getName
method on that value.
If the key has space, then you must enclose the key with quotes, for example 'foo bar':
simple("${body['foo bar'].name}")
You can access the Map
or List
objects directly using their key name (with or without dots) :
simple("${body[foo]}") simple("${body[this.is.foo]}")
Suppose there was no value with the key foo
then you can use the null safe operator to avoid the NPE as shown:
simple("${body[foo]?.name}")
You can also access List
types, for example to get lines from the address you can do:
simple("${body.address.lines[0]}") simple("${body.address.lines[1]}") simple("${body.address.lines[2]}")
There is a special last
keyword which can be used to get the last value from a list.
simple("${body.address.lines[last]}")
And to get the 2nd last you can subtract a number, so we can use last-1
to indicate this:
simple("${body.address.lines[last-1]}")
And the 3rd last is of course:
simple("${body.address.lines[last-2]}")
And you can call the size method on the list with
simple("${body.address.lines.size}")
Camel supports the length field for Java arrays as well, eg:
String[] lines = new String[]{"foo", "bar", "cat"}; exchange.getIn().setBody(lines); simple("There are ${body.length} lines")
And yes you can combine this with the operator support as shown below:
simple("${body.address.zip} > 1000")
92.4. Operator support
The parser is limited to only support a single operator.
To enable it the left value must be enclosed in $\\{ }. The syntax is:
${leftValue} OP rightValue
Where the rightValue
can be a String literal enclosed in ' '
, null
, a constant value or another expression enclosed in $\{ }
.
There must be spaces around the operator.
Camel will automatically type convert the rightValue type to the leftValue type, so it is able to eg. convert a string into a numeric, so you can use >
comparison for numeric values.
The following operators are supported:
Operator | Description |
---|---|
== | equals |
=~ | equals ignore case (will ignore case when comparing String values) |
> | greater than |
>= | greater than or equals |
< | less than |
⇐ | less than or equals |
!= | not equals |
!=~ | not equals ignore case (will ignore case when comparing String values) |
contains | For testing if contains in a string based value |
!contains | For testing if not contains in a string based value |
~~ | For testing if contains by ignoring case sensitivity in a string based value |
!~~ | For testing if not contains by ignoring case sensitivity in a string based value |
regex | For matching against a given regular expression pattern defined as a String value |
!regex | For not matching against a given regular expression pattern defined as a String value |
in | For matching if in a set of values, each element must be separated by comma. If you want to include an empty value, then it must be defined using double comma, eg ',,bronze,silver,gold', which is a set of four values with an empty value and then the three medals. |
!in | For matching if not in a set of values, each element must be separated by comma. If you want to include an empty value, then it must be defined using double comma, eg ',,bronze,silver,gold', which is a set of four values with an empty value and then the three medals. |
is | For matching if the left hand side type is an instance of the value. |
!is | For matching if the left hand side type is not an instance of the value. |
range |
For matching if the left hand side is within a range of values defined as numbers: |
!range |
For matching if the left hand side is not within a range of values defined as numbers: |
startsWith | For testing if the left hand side string starts with the right hand string. |
starts with | Same as the startsWith operator. |
endsWith | For testing if the left hand side string ends with the right hand string. |
ends with | Same as the endsWith operator. |
And the following unary operators can be used:
Operator | Description |
---|---|
++ | To increment a number by one. The left hand side must be a function, otherwise parsed as literal. |
— | To decrement a number by one. The left hand side must be a function, otherwise parsed as literal. |
\n | To use newline character. |
\t | To use tab character. |
\r | To use carriage return character. |
\} | To use the } character as text. This may be needed when building a JSon structure with the simple language. |
And the following logical operators can be used to group expressions:
Operator | Description |
---|---|
&& | The logical and operator is used to group two expressions. |
The logical or operator is used to group two expressions. |
The syntax for AND is:
${leftValue} OP rightValue && ${leftValue} OP rightValue
And the syntax for OR is:
${leftValue} OP rightValue || ${leftValue} OP rightValue
Some examples:
// exact equals match simple("${header.foo} == 'foo'") // ignore case when comparing, so if the header has value FOO this will match simple("${header.foo} =~ 'foo'") // here Camel will type convert '100' into the type of header.bar and if it is an Integer '100' will also be converter to an Integer simple("${header.bar} == '100'") simple("${header.bar} == 100") // 100 will be converter to the type of header.bar so we can do > comparison simple("${header.bar} > 100")
92.4.1. Comparing with different types
When you compare with different types such as String and int, then you have to take a bit care. Camel will use the type from the left hand side as 1st priority. And fallback to the right hand side type if both values couldn’t be compared based on that type.
This means you can flip the values to enforce a specific type. Suppose the bar value above is a String. Then you can flip the equation:
simple("100 < ${header.bar}")
which then ensures the int type is used as 1st priority.
This may change in the future if the Camel team improves the binary comparison operations to prefer numeric types to String based. It’s most often the String type which causes problem when comparing with numbers.
// testing for null simple("${header.baz} == null") // testing for not null simple("${header.baz} != null")
And a bit more advanced example where the right value is another expression
simple("${header.date} == ${date:now:yyyyMMdd}") simple("${header.type} == ${bean:orderService?method=getOrderType}")
And an example with contains, testing if the title contains the word Camel
simple("${header.title} contains 'Camel'")
And an example with regex, testing if the number header is a 4 digit value:
simple("${header.number} regex '\\d{4}'")
And finally an example if the header equals any of the values in the list. Each element must be separated by comma, and no space around.
This also works for numbers etc, as Camel will convert each element into the type of the left hand side.
simple("${header.type} in 'gold,silver'")
And for all the last 3 we also support the negate test using not:
simple("${header.type} !in 'gold,silver'")
And you can test if the type is a certain instance, eg for instance a String
simple("${header.type} is 'java.lang.String'")
We have added a shorthand for all java.lang
types so you can write it as:
simple("${header.type} is 'String'")
Ranges are also supported. The range interval requires numbers and both from and end are inclusive. For instance to test whether a value is between 100 and 199:
simple("${header.number} range 100..199")
Notice we use ..
in the range without spaces. It is based on the same syntax as Groovy.
simple("${header.number} range '100..199'")
As the XML DSL does not have all the power as the Java DSL with all its various builder methods, you have to resort to use some other languages for testing with simple operators. Now you can do this with the simple language. In the sample below we want to test if the header is a widget order:
<from uri="seda:orders"> <filter> <simple>${header.type} == 'widget'</simple> <to uri="bean:orderService?method=handleWidget"/> </filter> </from>
92.4.2. Using and / or
If you have two expressions you can combine them with the &&
or ||
operator.
For instance:
simple("${header.title} contains 'Camel' && ${header.type'} == 'gold'")
And of course the ||
is also supported. The sample would be:
simple("${header.title} contains 'Camel' || ${header.type'} == 'gold'")
92.5. Examples
In the XML DSL sample below we filter based on a header value:
<from uri="seda:orders"> <filter> <simple>${header.foo}</simple> <to uri="mock:fooOrders"/> </filter> </from>
The Simple language can be used for the predicate test above in the Message Filter pattern, where we test if the in message has a foo
header (a header with the key foo
exists). If the expression evaluates to true then the message is routed to the mock:fooOrders
endpoint, otherwise the message is dropped.
The same example in Java DSL:
from("seda:orders") .filter().simple("${header.foo}") .to("seda:fooOrders");
You can also use the simple language for simple text concatenations such as:
from("direct:hello") .transform().simple("Hello ${header.user} how are you?") .to("mock:reply");
Notice that we must use $\\{ } placeholders in the expression now to allow Camel to parse it correctly.
And this sample uses the date command to output current date.
from("direct:hello") .transform().simple("The today is ${date:now:yyyyMMdd} and it is a great day.") .to("mock:reply");
And in the sample below we invoke the bean language to invoke a method on a bean to be included in the returned string:
from("direct:order") .transform().simple("OrderId: ${bean:orderIdGenerator}") .to("mock:reply");
Where orderIdGenerator
is the id of the bean registered in the Registry. If using Spring then it is the Spring bean id.
If we want to declare which method to invoke on the order id generator bean we must prepend .method name
such as below where we invoke the generateId
method.
from("direct:order") .transform().simple("OrderId: ${bean:orderIdGenerator.generateId}") .to("mock:reply");
We can use the ?method=methodname
option that we are familiar with the Bean component itself:
from("direct:order") .transform().simple("OrderId: ${bean:orderIdGenerator?method=generateId}") .to("mock:reply");
You can also convert the body to a given type, for example to ensure that it is a String you can do:
<transform> <simple>Hello ${bodyAs(String)} how are you?</simple> </transform>
There are a few types which have a shorthand notation, so we can use String
instead of java.lang.String
. These are: byte[], String, Integer, Long
. All other types must use their FQN name, e.g. org.w3c.dom.Document
.
It is also possible to lookup a value from a header Map
:
<transform> <simple>The gold value is ${header.type[gold]}</simple> </transform>
In the code above we lookup the header with name type
and regard it as a java.util.Map
and we then lookup with the key gold
and return the value. If the header is not convertible to Map an exception is thrown. If the header with name type
does not exist null
is returned.
You can nest functions, such as shown below:
<setHeader name="myHeader"> <simple>${properties:${header.someKey}}</simple> </setHeader>
92.6. Setting result type
You can now provide a result type to the Simple expression, which means the result of the evaluation will be converted to the desired type. This is most usable to define types such as booleans, integers, etc.
For example to set a header as a boolean type you can do:
.setHeader("cool", simple("true", Boolean.class))
And in XML DSL
<setHeader name="cool"> <!-- use resultType to indicate that the type should be a java.lang.Boolean --> <simple resultType="java.lang.Boolean">true</simple> </setHeader>
92.7. Using new lines or tabs in XML DSLs
It is easier to specify new lines or tabs in XML DSLs as you can escape the value now
<transform> <simple>The following text\nis on a new line</simple> </transform>
92.8. Leading and trailing whitespace handling
The trim attribute of the expression can be used to control whether the leading and trailing whitespace characters are removed or preserved. The default value is true, which removes the whitespace characters.
<setBody> <simple trim="false">You get some trailing whitespace characters. </simple> </setBody>
92.9. Loading script from external resource
You can externalize the script and have Camel load it from a resource such as "classpath:"
, "file:"
, or "http:"
. This is done using the following syntax: "resource:scheme:location"
, e.g. to refer to a file on the classpath you can do:
.setHeader("myHeader").simple("resource:classpath:mysimple.txt")
92.10. Spring Boot Auto-Configuration
When using simple 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> </dependency>
The component supports 147 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.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 |