Bean Validator Component

Available as of Camel version 2.3

The Validator component performs bean validation of the message body using the Java Bean Validation API (JSR 303). Camel uses the reference implementation, which is Hibernate Validator.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-bean-validator</artifactId>
    <version>x.y.z</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

bean-validator:label[?options]

or

bean-validator://label[?options]

Where label is an arbitrary text value describing the endpoint.
You can append query options to the URI in the following format, ?option=value&option=value&…​

URI Options

The Bean Validator component supports 1 options, which are listed below.

Name Description Default Type

basicPropertyBinding (advanced)

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

The Bean Validator endpoint is configured using URI syntax:

bean-validator:label

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

label

Required Where label is an arbitrary text value describing the endpoint

String

Query Parameters (8 parameters):

Name Description Default Type

constraintValidatorFactory (producer)

To use a custom ConstraintValidatorFactory

ConstraintValidatorFactory

group (producer)

To use a custom validation group

javax.validation.groups.Default

String

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

messageInterpolator (producer)

To use a custom MessageInterpolator

MessageInterpolator

traversableResolver (producer)

To use a custom TraversableResolver

TraversableResolver

validationProviderResolver (producer)

To use a a custom ValidationProviderResolver

ValidationProviderResolver

basicPropertyBinding (advanced)

Whether the endpoint should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

boolean

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-bean-validator-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 2 options, which are listed below.

Name Description Default Type

camel.component.bean-validator.basic-property-binding

Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities

false

Boolean

camel.component.bean-validator.enabled

Enable bean-validator component

true

Boolean

OSGi deployment

To use Hibernate Validator in the OSGi environment use dedicated ValidationProviderResolver implementation, just as org.apache.camel.component.bean.validator.HibernateValidationProviderResolver. The snippet below demonstrates this approach. You can also use HibernateValidationProviderResolver.

Using HibernateValidationProviderResolver

from("direct:test").
  to("bean-validator://ValidationProviderResolverTest?validationProviderResolver=#myValidationProviderResolver");

...

<bean id="myValidationProviderResolver" class="org.apache.camel.component.bean.validator.HibernateValidationProviderResolver"/>

If no custom ValidationProviderResolver is defined and the validator component has been deployed into the OSGi environment, the HibernateValidationProviderResolver will be automatically used.

Example

Assumed we have a java bean with the following annotations

Car.java

public class Car {

    @NotNull
    private String manufacturer;

    @NotNull
    @Size(min = 5, max = 14, groups = OptionalChecks.class)
    private String licensePlate;

    // getter and setter
}

and an interface definition for our custom validation group

OptionalChecks.java

public interface OptionalChecks {
}

with the following Camel route, only the @NotNull constraints on the attributes manufacturer and licensePlate will be validated (Camel uses the default group javax.validation.groups.Default).

from("direct:start")
.to("bean-validator://x")
.to("mock:end")

If you want to check the constraints from the group OptionalChecks, you have to define the route like this

from("direct:start")
.to("bean-validator://x?group=OptionalChecks")
.to("mock:end")

If you want to check the constraints from both groups, you have to define a new interface first

AllChecks.java

@GroupSequence({Default.class, OptionalChecks.class})
public interface AllChecks {
}

and then your route definition should looks like this

from("direct:start")
.to("bean-validator://x?group=AllChecks")
.to("mock:end")

And if you have to provide your own message interpolator, traversable resolver and constraint validator factory, you have to write a route like this

<bean id="myMessageInterpolator" class="my.ConstraintValidatorFactory" />
<bean id="myTraversableResolver" class="my.TraversableResolver" />
<bean id="myConstraintValidatorFactory" class="my.ConstraintValidatorFactory" />

from("direct:start")
.to("bean-validator://x?group=AllChecks&messageInterpolator=#myMessageInterpolator
&traversableResolver=#myTraversableResolver&constraintValidatorFactory=#myConstraintValidatorFactory")
.to("mock:end")

It’s also possible to describe your constraints as XML and not as Java annotations. In this case, you have to provide the file META-INF/validation.xml which could looks like this

validation.xml

<?xml version="1.0" encoding="UTF-8"?>
<validation-config
    xmlns="http://jboss.org/xml/ns/javax/validation/configuration"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://jboss.org/xml/ns/javax/validation/configuration">
    <default-provider>org.hibernate.validator.HibernateValidator</default-provider>
    <message-interpolator>org.hibernate.validator.engine.ResourceBundleMessageInterpolator</message-interpolator>
    <traversable-resolver>org.hibernate.validator.engine.resolver.DefaultTraversableResolver</traversable-resolver>
    <constraint-validator-factory>org.hibernate.validator.engine.ConstraintValidatorFactoryImpl</constraint-validator-factory>

    <constraint-mapping>/constraints-car.xml</constraint-mapping>
</validation-config>

and the constraints-car.xml file

constraints-car.xml

<?xml version="1.0" encoding="UTF-8"?>
<constraint-mappings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://jboss.org/xml/ns/javax/validation/mapping validation-mapping-1.0.xsd"
    xmlns="http://jboss.org/xml/ns/javax/validation/mapping">
    <default-package>org.apache.camel.component.bean.validator</default-package>

    <bean class="CarWithoutAnnotations" ignore-annotations="true">
        <field name="manufacturer">
            <constraint annotation="javax.validation.constraints.NotNull" />
        </field>

        <field name="licensePlate">
            <constraint annotation="javax.validation.constraints.NotNull" />

            <constraint annotation="javax.validation.constraints.Size">
                <groups>
                    <value>org.apache.camel.component.bean.validator.OptionalChecks</value>
                </groups>
                <element name="min">5</element>
                <element name="max">14</element>
            </constraint>
        </field>
    </bean>
</constraint-mappings>

Note that the body should include an instance of a class to validate.

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://camel.apache.org/schema/spring http://camel.apache.org/schema/spring/camel-spring.xsd">

    <camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
        <route>
            <from uri="direct:start"/>
            <to uri="bean-validator://x?group=org.apache.camel.component.bean.validator.OrderedChecks"/>
        </route>
    </camelContext>
</beans>