java-bootstrapper

Bootstrapping library for java to allow dependency updates and isolated loading of dependencies after initialisation.

Usage

First you need to customise the configuration file in src/main/resources/config.properties (all configuration files are simple key=value property files.

baseDir = {directory to install into}
versionUrl = {URL to check for version updates}

The bootstrapper can be built with mvn clean package and the executable jar used to run your application.

Before running, the entry in versionUrl should hold a configuration file of the following format.

latest.version = {version to install - simple integer, starting at 1}
latest.downloadFile = {zip file containing all the dependencies required to run your application - no nested directories}
latest.mainClass = {class used to start your application}

How It Works

When the bootstrapper starts, the following actions are taken;

• baseDir is checked for a version.properties file, if not found, current version is assumed to be 0
• versionUrl is checked and if the latest.version > local.version an upgrade starts
  • latest.downloadFile is downloaded and unpacked into baseDir/lib/{VERSION}
  • version.properties file is updated to include local.version and local.mainClass (taken from latest.version and latest.mainClass in versionUrl property file)
• Any jar files within baseDir/lib/{VERSION} are loaded and the main method from local.mainClass is executed with an empty String[] passed in

Application updates can be performed by updating the property file at versionUrl (remembering to increment the version) and creating a new zip file of dependencies - located at latest.downloadFile

Future Updates

• Tool to help build the property file located at versionUrl
• Signing for boostrapper and update files