JQ

Since Camel 3.18

Camel supports JQ to allow using Expression or Predicate on JSON messages.

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.

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");

Message body types

Camel JQ leverages camel-jackson for type conversion. To enable camel-jackson POJO type conversion, refer to the Camel Jackson documentation.

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");

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");

Dependencies

If you use Maven you could just add the following to your pom.xml, substituting the version number for the latest and greatest release (see the download page for the latest versions).

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-jq</artifactId>
  <version>x.x.x</version>
</dependency>

Spring Boot Auto-Configuration

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

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
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