JBang is a tool that lets you write Java apps easily, no Maven, no Gradle, just pure Java classes with some small directives as comments in the header.
///usr/bin/env jbang "$0" "$@" ; exit $?
import static java.lang.System.out;
public class hello {
public static void main(String... args) {
out.println("Hello World");
}
}jbang hello.java
[jbang] Building jar...
Hello WorldWith the help of JBang, developers are able to create and share their scripts for the public! It can be done with a so called catalog.
Catalogs (simple JSON files) can be put into a Git repository and other developers are able to fetch, build and run the scripts listed in them.
An example jbang-catalog.json
{
"catalogs": {
"jooq": {
"catalog-ref": "https://github.com/jooq/jbang-catalog/blob/HEAD/jbang-catalog.json"
},
"rodnansol": {
"catalog-ref": "https://github.com/rodnansol/jbang-catalog/blob/HEAD/jbang-catalog.json",
"description": "Rodnan Sol JBang Catalog"
}
},
"aliases": {
"hello": {
"script-ref": "hello.java",
"description": "Script that says hello back for each argument"
}
},
"templates": {
"q-aws-lambda-tf": {
"file-refs": {
"{filename}": "aws/aws-lambda.java.qute",
"build-application": "aws/build-application",
"application.properties": "aws/application.properties",
"lambda-{basename}.tf": "aws/lambda.tf.qute"
},
"description": "Quarkus AWS Lambda template with Terraform template. Use the -Dnative-function flag to have native image based Terraform resources",
"properties": {
"mode": {
"description": "Quarkus Lambda mode: simple or funq",
"default": "simple"
},
"tf-providers": {
"description": "If enabled extra Terraform related providers will be generated",
"default": false
},
"tf-provider-aws-version": {
"description": "Version of the AWS Terraform provider",
"default": "3.71.0"
},
"tf-provider-archive-version": {
"description": "Version of the Archive Terraform provider",
"default": "2.2.0"
},
"tf-provider-null-version": {
"description": "Version of the NULL Terraform provider",
"default": "3.1.0"
},
"tf-provider-aws-region": {
"description": "AWS Region",
"default": "eu-central-1"
},
"aws-vpc-integration": {
"description": "AWSLambdaVPCAccessExecutionRole will be added to the lambda function ",
"default": false
},
"aws-lambda-logging": {
"description": "If logging should be enabled or not",
"default": false
},
"native-function": {
"description": "Native executable based lambda or not",
"default": false
},
"lambda-handler": {
"description": "Lambda handler method's name. By default it will be decided by the 'mode' property, but could be overriden."
}
}
}
}
}A catalog can store:
-
References to other catalogs (in local environment it provides ability to alias scripts)
-
Create aliases
-
Create templates with properties
With the help of this project the goal is to give a unified solution for these JBang catalog repositories, developers who are sharing their work with the outside world, they should do it with fashion.
Let us introduce the JBang Catalog Document Generator that takes your jbang-catalog.json file and it converts to a:
-
AsciiDoc
-
Markdown
document that can be put into your repository and others can easily browse your available scripts.
name: update-catalog
on:
push:
branches:
- main
workflow_dispatch:
jobs:
update-catalog-documentation:
runs-on: ubuntu-latest
name: Update catalog documentation
if: startsWith(github.event.head_commit.message, 'Updating jbang-catalog documentation') != true
steps:
- uses: actions/checkout@v3
- uses: rodnansol/[email protected] # (1)
name: Generate catalog document
with:
version: early-access # (2)
arguments: generate jbang-catalog.json -o README.adoc --custom-header=header.adoc --include-generation-date=true # (3)
- name: Commit document changes
shell: bash
run: |
git add README.adoc # (4)
git config --global user.email "${{ secrets.COMMITTER_EMAIL }}"
git config --global user.name "${{ secrets.COMMITTER_NAME }}"
git commit -m "Updating jbang-catalog documentation" # (5)
git push origin main-
Add the
rodnansol/jbang-catalog-document-generator-actionto your action. Check the latest version before doing so. -
Specify the version of the CLI tool you want to use.
-
By default, the
generate jbang-catalog.jsoncommand will be executed with, if more customization is needed specify it here -
Do not forget to add it to the staging area
-
Commit and then push the files
More information about the action can be found here.
Download the uber-jar/fatjar and run it with Java 17(!).
java -jar jbang-catalog-document-generator-cli/target/jbang-catalog-document-generator-cli-999-SNAPSHOT.jar generate
Usage: <main class> generate [-g] [-cc] [-cus] [-hfdr] [-toc]
[-cf=<customFooterFilePath>]
[-ch=<customHeaderFilePath>] [-o=<outputFile>]
[-pcn=<preferredCatalogName>]
[-t=<customTemplatePath>] [-toc-l=<tocLevels>]
[-toc-p=<tocPlacement>] [-toc-t=<tocTitle>]
[-tt=<templateType>] <inputFile>
Generates a documentation for a given jbang-catalog.json file
<inputFile> The input JSON file to convert.
-cc, --check-checksum
Defines if the checksum check should be running or not.
Checksum check is enabled by default.
-cf, --custom-footer=<customFooterFilePath>
Path to a custom footer.
-ch, --custom-header=<customHeaderFilePath>
Path to a custom header.
-cus, --collapsible-usage-section
Defines if the usage section should be collapsible or not
-g, --include-generation-date
Defines if the generation date should be put into the
document or not.
-hfdr, --header-footer-direct-render
Defines if the header and footer should be directly
rendered into the document or not. In case of AsciiDoc it
will not use the `include` directive.
-o, --output=<outputFile>
The output AsciiDoc file name. Defaults to 'jbang-catalog.
adoc'
-pcn, --preferred-catalog-name=<preferredCatalogName>
Defines the preferred catalog name.
-t, --template=<customTemplatePath>
Custom template path.
-toc, --table-of-contents
Enable the table of contents or not
-toc-l, --table-of-contents-levels=<tocLevels>
Levels of the table of contents (In case of AsciiDoc)
-toc-p, --table-of-contents-placement=<tocPlacement>
Placement of the table of contents (In case of AsciiDoc)
-toc-t, --table-of-contents-title=<tocTitle>
Title of the table of contents
-tt, --template-type=<templateType>
Template type.A tool for JBang will not be truly JBang related if it would not be having a JBang script.
The tool is available within a Docker image, check the packages of the organization.
docker run -v $(pwd):/resources ghcr.io/rodnansol/jbang-catalog-document-generator:<version> generate /resources/jbang-catalog.json -o /resources/jbang-catalog.adoc
Custom header and custom footer can be attached to make sure introductions and other important stuff can be put into the final document.
The alias entries can be extended with a help/usage section where the usage of the script can have a detailed description, for example if it is a CLI application the usage of the app or the flags can be put here.
{
"aliases": {
"hello": {
"script-ref": "hello.java",
"description": "Script that says hello back for each argument"
}
}
}This is a usage file, that will be rendered below the `hello` alias entry.
!%$&@ So you want to use this script? !%$&@
< Let me show you how you can use it. >It can put behind a collapsible section with the -cus (--collapsible-usage-section) flag.
Since the 0.2.0 version the current working directory can be overwritten which can help you to read the usages from a different path if you wish. It can be overwritten with the -Dapp.document.current-working-directory= flag when using the java command.
java -Dapp.document.current-working-directory=new-working/directory -jar jbang-catalog-document-generator-cli.jar generate jbang-catalog.jsonIn this case the alias usages will be read from the new-working/directory folder.
The project requires at least GraalVM 22.3 / Java 17, if SDKMan is installed on your machine sdk e command could be used in the terminal to set up the required Java version.
-
To build the project just run:
mvn package
The project contains a .editorconfig file, and it should be utilized as well.
During build time Checkstyle checks the conventions.
The commit messages are based on the conventional-commits, please apply those rules.
Learn more here.
Check the list of contributors here.
