- Technical requirements
- Supported protocols
- How to use the template
- Template configuration
- Environment variables
- Key Files
- Container Information
- Future Enhancements
This template generates Java application code based from an AsyncAPI document.
Implementations are provided for the following protocols:
ibmmq- generating Java JMS code (utilising features from the IBM MQ AsyncAPI bindings)
kafka- generating Java code (utilising features from the Apache Kafka AsyncAPI bindings)
- This is implemented using the JMS API with the correct jars, in this case ibmmq was chosen. The use of JMS allows allows the template to be extensible to other providers by providing the correct jars at the Maven stage.
- This is implemented using the official client library from the Apache Kafka project.
How to use the template
This template must be used with the AsyncAPI Generator. You can find all available options here.
# Install the AsyncAPI Generator npm install -g @asyncapi/generator # Run generation ag https://ibm.biz/mq-asyncapi-yml-sample @asyncapi/java-template -o output -p server=production
For complete instructions on generating the Java and subsequently using it to send messages, please see the relevant tutorial:
You can configure this template by passing different parameters in the Generator CLI:
-p PARAM1_NAME=PARAM1_VALUE -p PARAM2_NAME=PARAM2_VALUE
||Server must be defined in yaml and selected when using the generator||Yes||-|
||User for the server to generate code for. This can also be provided as an environment variable (see below)||No||app|
||Password for the server to generate code for. This can also be provided as an environment variable (see below)||No||passw0rd|
||Java package name for generated code||No||com.ibm.mq.samples.jms|
||MQ topic prefix. Used for ibmmq protocols. Default will work with dev MQ instance||No||dev//|
||Custom output location of the AsyncAPI file that you provided as an input||No||The root of the output directory|
Credentials can be provided as environment variables if preferred. If set, these credentials will override those set with the template parameters.
All credentials are stored in
env.json in the output directory, so they can be updated at any time without needing to run the generator or recompile the Java.
The most straightforward command to use this template is:
ag https://ibm.biz/mq-asyncapi-yml-sample @asyncapi/java-template -o output -p server=production
For local development, you need different variations of this command. First of all, you need to know about three important CLI flags:
--debugenables the debug mode in Nunjucks engine what makes filters debugging simpler.
--watch-templateenables a watcher of changes that you make in the template. It regenerates your template whenever it detects a change.
--installenforces reinstallation of the template.
There are two ways you can work on template development:
- Use global Generator and template from your local sources:
# assumption is that you run this command from the root of your template ag https://ibm.biz/mq-asyncapi-yml-sample @asyncapi/java-template -o output -p server=production
- Use Generator from sources and template also from local sources. This approach enables more debugging options with awesome
console.login the Generator sources or even the Parser located in
node_modulesof the Generator:
# assumption is that you run this command from the root of your template # assumption is that generator sources are cloned on the same level as the template ../generator/cli.js https://ibm.biz/mq-asyncapi-yml-sample @asyncapi/java-template -o output -p server=production
As a developer, you may want to make changes to how the generator operates. This non-exhaustive list aims to show the files you will likely need to change most.
|template/index.js||Entry point for the application|
|components/Common.js||Common/helper functions used across the generator|
|utils/*||Contains all filters|
|components/*||Contains reusable components|
Note: Files in the output directory are generated using the ag command, detailed in the above section.
|output/env.json||Used for setting environmental variables such as username and password|
|output/com/ibm/mq/samples/jms/PubSubBase.java||The base used for generated publishers and subscribers|
To run the generated Java project in a Docker container, use the commands as below:
Build the image
docker build -t [PACKAGE_NAME]:[VERSION] .
Run the image in detached mode
docker run -d [PACKAGE_NAME]:[VERSION]
For further information including network setup, please see the tutorial.
- General enhancements
- Add support for multiple messages per channel (ofMany)
- Support for MQTT
- Support for other protocols
- Add support for TLS connections
- Add support for more JMS Types alongside JMS Text
- Offer Java event listener support for consumers
Thanks goes to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome!