First steps
The following guide outlines various ways to create a Camel Quarkus project.
Prerequisites
-
A
git
client -
An IDE
-
JDK 8+ with JAVA_HOME configured appropriately
-
Apache Maven 3.6.2+
-
GraalVM with the
native-image
command installed and theGRAALVM_HOME
environment variable set. See Building a native executable section of the Quarkus documentation. -
If you are on Linux,
docker
is sufficient for the native mode too. Use-Pnative,docker
instead of-Pnative
if you choose this option.
code.quarkus.io
Projects can be bootstrapped and generated at https://code.quarkus.io. All of the Camel Quarkus extensions can be found under the 'Integration' heading. Use the 'search' field to help with finding extensions that you are interested in.
Simply select the component extensions that you want to work with and click the 'Generate your application' button to download a basic skeleton project. There is also the option to push the project directly to GitHub.
When the project archive download has completed successfully, unzip and import into your favorite IDE.
Maven plugin
Quarkus provides a Maven plugin that enables you to quickly bootstrap projects. For example, to create a project skeleton that includes the timer
and log
component extensions:
$ mvn io.quarkus:quarkus-maven-plugin:1.8.3.Final:create \
-DprojectGroupId=org.acme \
-DprojectArtifactId=getting-started \
-Dextensions=camel-quarkus-log,camel-quarkus-timer
$ cd getting-started
Windows users should omit the \ if using cmd . When using Powershell , wrap the -D parameters in double quotes.
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Gradle support is also available. See the Quarkus Gradle guide for more information.
IDE plugins
Quarkus has plugins for most of the popular development IDEs. They provide Quarkus language support, code / config completion, project creation wizards and much more. The plugins are available at each respective IDE marketplace.
Check the plugin documentation to discover how to create projects for your preferred IDE.
Example projects
Camel Quarkus provides a GitHub repository containing a set of example projects.
The master branch is always aligned with the latest Camel Quarkus release.
Step by step with the rest-json
example
-
Clone the Camel Quarkus example projects.
$ git clone https://github.com/apache/camel-quarkus-examples.git
-
Copy the
rest-json
example out of the source tree.$ cp -r camel-quarkus-examples/rest-json . $ cd rest-json
-
Open the
pom.xml
file in your IDE. Change the projectgroupId
,artifactId
&version
as necessary.
Explore the application code
The application has three compile dependencies:
<dependency>
<groupId>org.apache.camel.quarkus</groupId>
<artifactId>camel-quarkus-main</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel.quarkus</groupId>
<artifactId>camel-quarkus-platform-http</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-quarkus-jackson</artifactId>
</dependency>
They are managed within the camel-quarkus-bom
that is imported in <dependencyManagement>
.
There are only three classes in the application/ Routes
defining the Camel routes and a couple of entity classes. Fruit
and Legume
.
The application is configured by properties defined within src/main/resources/application.properties
. E.g. the camel.context.name
is set there.
Development mode
$ mvn clean compile quarkus:dev
This command compiles the project, starts your application and lets the Quarkus tooling watch for changes in your workspace. Any modifications in your project will automatically take effect in the running application.
Check the application in the browser, e.g. http://localhost:8080/fruits
for the rest-json
example
Then change something in the code and see the changes applied by refreshing the browser.
Please refer to Quarkus documentation for more details.
Testing
There are two test classes in our example: RestJsonTest
is for the JVM mode while RestJsonIT
is there for the native
mode.
The JVM mode tests are run by maven-surefire-plugin
in the test
Maven phase:
$ mvn clean test
This should take about 15 seconds.
The native mode tests are verified by maven-failsafe-plugin
in the verify
phase. Pass the native
property to
activate the profile that runs them:
$ mvn clean verify -Pnative
This takes about 2.5 minutes (once you have all dependencies cached).
Package and run the application
JVM mode
mvn package
prepares a thin jar
for running on a stock JVM:
$ mvn clean package
$ ls -lh target
...
-rw-r--r--. 1 ppalaga ppalaga 238K Oct 11 18:55 my-app-0.0.1-SNAPSHOT-runner.jar
...
You can run it as follows:
$ java -jar target/*-runner.jar
...
[io.quarkus] (main) Quarkus started in 1.163s. Listening on: http://[::]:8080
Notice the boot time around a second.
The thin jar
contains just the application code. To run it, the dependencies in target/lib
are required too.
Native mode
To prepare a native executable using GraalVM, run the following command:
$ mvn clean package -Pnative
$ ls -lh target
...
-rwxr-xr-x. 1 ppalaga ppalaga 46M Oct 11 18:57 my-app-0.0.1-SNAPSHOT-runner
...
Note that the runner
in the listing above has no .jar
extension and has the x
(executable) permission set. Thus
it can be run directly:
$ ./target/*-runner
...
[io.quarkus] (main) Quarkus started in 0.013s. Listening on: http://[::]:8080
...
Check how fast it started and check how little memory it consumes:
$ ps -o rss,command -p $(pgrep my-app)
RSS COMMAND
34916 ./target/my-app-0.0.1-SNAPSHOT-runner
That’s under 35 MB of RAM!
Quarkus Native executable guide contains more details including steps for creating a container image. |