[[bean-validator-component]]
== 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
(http://jcp.org/en/jsr/detail?id=303[JSR 303]). Camel uses the reference
implementation, which is
http://docs.jboss.org/hibernate/validator/4.3/reference/en-US/html_single/[Hibernate
Validator].

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

[source,xml]
------------------------------------------------------------
<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

[source,java]
------------------------------
bean-validator:label[?options]
------------------------------

or

[source,java]
--------------------------------
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


// component options: START
The Bean Validator component has no options.
// component options: END



// endpoint options: START
The Bean Validator endpoint is configured using URI syntax:

----
bean-validator:label
----

with the following path and query parameters:

==== Path Parameters (1 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *label* | *Required* Where label is an arbitrary text value describing the endpoint |  | String
|===


==== Query Parameters (6 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *constraintValidatorFactory* (producer) | To use a custom ConstraintValidatorFactory |  | ConstraintValidator Factory
| *group* (producer) | To use a custom validation group | javax.validation.groups.Default | String
| *messageInterpolator* (producer) | To use a custom MessageInterpolator |  | MessageInterpolator
| *traversableResolver* (producer) | To use a custom TraversableResolver |  | TraversableResolver
| *validationProviderResolver* (producer) | To use a a custom ValidationProviderResolver |  | ValidationProvider Resolver
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
|===
// endpoint options: END
// spring-boot-auto-configure options: START
=== Spring Boot Auto-Configuration

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

[source,xml]
----
<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.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| Name | Description | Default | Type
| *camel.component.bean-validator.enabled* | Enable bean-validator component | true | Boolean
| *camel.component.bean-validator.resolve-property-placeholders* | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | Boolean
|===
// spring-boot-auto-configure options: END



### 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. Keep in mind that you can
use `HibernateValidationProviderResolver` starting from the Camel
2.13.0.

*Using HibernateValidationProviderResolver*

[source,java]
--------------------------------------------------------------------------------------------------------------------------------
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*

[source,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*

[source,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`).

[source,java]
-------------------------
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

[source,java]
----------------------------------------------
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*

[source,java]
-----------------------------------------------------
@GroupSequence({Default.class, OptionalChecks.class})
public interface AllChecks {
}
-----------------------------------------------------

and then your route definition should looks like this

[source,java]
-----------------------------------------
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

[source,java]
------------------------------------------------------------------------------------------------------
<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*

[source,java]
------------------------------------------------------------------------------------------------------------------------------
<?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*

[source,java]
----------------------------------------------------------------------------------------------------
<?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>
----------------------------------------------------------------------------------------------------

Here is the XML syntax for the example route definition where **OrderedChecks** can be https://github.com/apache/camel/blob/master/components/camel-bean-validator/src/test/java/org/apache/camel/component/bean/validator/OrderedChecks.java 

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

[source,java]
----------------------------------------------------------------------------------------------------

<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>
----------------------------------------------------------------------------------------------------



### See Also

* Configuring Camel
* Component
* Endpoint
* Getting Started
