Chapter 49. JQ Since Camel 3.18 Camel supports JQ to allow using Expression or Predicate on JSON messages. 49.1. Dependencies When using jq with Red Hat build of Camel Spring Boot, use the following Maven dependency to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-jq-starter</artifactId> </dependency> 49.2. JQ Options The JQ language supports 4 options, which are listed below. Name Default Java Type Description headerName String Name of header to use as input, instead of the message body It has as higher precedent than the propertyName if both are set. propertyName String Name of property to use as input, instead of the message body. It has a lower precedent than the headerName if both are set. resultType String Sets the class of the result type (type from output). trim true Boolean Whether to trim the value to remove leading and trailing whitespaces and line breaks. 49.3. Examples For example, you can use JQ in a Predicate with the Content Based Router EIP . from("queue:books.new") .choice() .when().jq(".store.book.price < 10)") .to("jms:queue:book.cheap") .when().jq(".store.book.price < 30)") .to("jms:queue:book.average") .otherwise() .to("jms:queue:book.expensive"); 49.4. Message body types Camel JQ leverages camel-jackson for type conversion. To enable camel-jackson POJO type conversion, refer to the Camel Jackson documentation. 49.5. Using header as input By default, JQ uses the message body as the input source. However, you can also use a header as input by specifying the headerName option. For example to count the number of books from a JSON document that was stored in a header named books you can do: from("direct:start") .setHeader("numberOfBooks") .jq(".store.books | length", int.class, "books") .to("mock:result"); 49.6. Camel supplied JQ Functions The camel-jq adds the following functions: header - Allow to access the Message header in a JQ expression. For example, to set the property foo with the value from the Message header `MyHeader': from("direct:start") .transform() .jq(".foo = header(\"MyHeader\")") .to("mock:result"); 49.7. Spring Boot Auto-Configuration The component supports 4 options, which are listed below. Name Description Default Type camel.language.jq.enabled Whether to enable auto configuration of the jq language. This is enabled by default. Boolean camel.language.jq.header-name Name of header to use as input, instead of the message body It has as higher precedent than the propertyName if both are set. String camel.language.jq.property-name Name of property to use as input, instead of the message body. It has a lower precedent than the headerName if both are set. String camel.language.jq.trim Whether to trim the value to remove leading and trailing whitespaces and line breaks. true Boolean

Commands:
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-jq-starter</artifactId> </dependency>
from("queue:books.new") .choice() .when().jq(".store.book.price < 10)") .to("jms:queue:book.cheap") .when().jq(".store.book.price < 30)") .to("jms:queue:book.average") .otherwise() .to("jms:queue:book.expensive");
from("direct:start") .setHeader("numberOfBooks") .jq(".store.books | length", int.class, "books") .to("mock:result");
from("direct:start") .transform() .jq(".foo = header(\"MyHeader\")") .to("mock:result");