Paho Component
Available as of Camel 2.16
Paho component provides connector for the MQTT messaging protocol using the Paho library.
Adding the component to the project
Maven users will need to add the following dependency to their pom.xml
for this component:
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-paho</artifactId> <version>x.y.z</version> <!-- use the same version as your Camel core version --> </dependency>
URI format
paho:queueName[?options]
You can append query options to the URI in the following format: ?option=value&option=value&...
.
URI Options
Option | Default | Description |
---|---|---|
|
| The URL of the MQTT broker. |
persistence | memory | Client persistence to be used - memory or file . |
qos | 2 | Client quality of service level (0 -2 ). |
Example
Assumed we have a java bean with the following annotations
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
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
@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
and the constraints-car.xml
file