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Available as of Apache Camel 2.3

The Validation component performs bean validation of the message body using the Java Bean Validation API (JSR 303). Apache 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.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

The following URI options are supported:

Option Default Description
group javax.validation.groups.Default The custom validation group to use.
messageInterpolator org.hibernate.validator.engine. ResourceBundleMessageInterpolator Reference to a custom javax.validation.MessageInterpolator in the Registry.
traversableResolver org.hibernate.validator.engine.resolver. DefaultTraversableResolver Reference to a custom javax.validation.TraversableResolver in the Registry.
constraintValidatorFactory org.hibernate.validator.engine. ConstraintValidatorFactoryImpl Reference to a custom javax.validation.ConstraintValidatorFactory in the Registry.

Assumed we have a java bean with the following annotations

[Note]Car.java
// 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

[Note]OptionalChecks.java
public interface OptionalChecks {
}

with the following Apache Camel route, only the @NotNull constraints on the attributes manufacturer and licensePlate will be validated (Apache 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

[Note]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

[Note]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

[Note]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>

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