docs/components/modules/ROOT/pages/bean-validator-component.adoc

[[bean-validator-component]]
= Bean Validator Component
:page-source: components/camel-bean-validator/src/main/docs/bean-validator-component.adoc

*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 supports 1 options, which are listed below.



[width="100%",cols="2,5,^1,2",options="header"]
|===
| 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
|===
// 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 (8 parameters):


[width="100%",cols="2,5,^1,2",options="header"]
|===
| 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
|===
// 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.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
|===
// 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. You can also
use `HibernateValidationProviderResolver`.

*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>
----------------------------------------------------------------------------------------------------