Shell for PF4J

Interactive shell for PF4J.

Features/Benefits

Use the shell to interact with PF4j.

You can interact with the PluginManager (see manager command) and execute the following actions:

• display info about manager (plugins_roots, system_version, runtime_mode)
• see unresolved plugins
• see all the extensions added by the all plugins
• which plugin loaded the given class (as parameter)

You can interact with plugins (see plugins command) and execute the following actions:

• display info about all plugins (id, version, state)
• load plugins
• reload plugins
• unload plugins
• start plugins
• stop plugins

You can interact with a specific plugin (see plugin command) and execute the following actions:

• display info about plugin (id, version, state, path, provider, description, dependencies, classloader, ..)
• load plugin
• unload plugin
• start plugin
• stop plugin

You can interact with ClassLoaders (see classloader command) and execute the following actions:

• display info about all classloaders
• display the plugins classloaders
• display the urls for a specific plugin classloader (what jars, directories the plugin adds)
• display the loadedClasses for a specific plugin classloader

How to use

It's very simple to add pf4j-shell in your application.

Define an extension point in your application/plugin using ExtensionPoint interface marker:

public class Boot {

    public static void main(String[] args) {
        // create the plugin manager
        PluginManager pluginManager = new DemoPluginManager();

        // create shell
        Shell shell = new Shell(pluginManager);

        // start shell
        shell.start();
    }
}

For more details see Boot.java that comes with demo.

The output is:

22:23:25 [main] INFO org.pf4j.demo.Boot - ########################################
22:23:25 [main] INFO org.pf4j.demo.Boot -                PF4J-DEMO                
22:23:25 [main] INFO org.pf4j.demo.Boot - ########################################
22:23:25 [main] INFO org.pf4j.DefaultPluginStatusProvider - Enabled plugins: []
22:23:25 [main] INFO org.pf4j.DefaultPluginStatusProvider - Disabled plugins: []
22:23:25 [main] INFO org.pf4j.DefaultPluginManager - PF4J version 3.9.0 in 'deployment' mode
pf4j-shell> 

Now you can start to run commands

See all commands available:

pf4j-shell> help
 -  PicocliCommands registry
Summary: classloader 
         clear       Clears the screen
         cls         Clears the screen
         help        
         manager     
         plugin      
         plugins     

Get information about manager:

pf4j-shell> manager 
Plugins roots: [plugins]
System version: 0.0.0
Runtime mode: deployment

Load all plugins:

pf4j-shell> plugins load
pf4j-shell> plugins 
            Id|Version|   State
--------------+-------+--------
welcome-plugin|  0.0.1|RESOLVED
  hello-plugin|  0.0.1|RESOLVED

Start all plugins:

pf4j-shell> plugins start 
Start plugins ...
22:31:56 [main] INFO org.pf4j.AbstractPluginManager - Start plugin 'welcome-plugin@0.0.1'
22:31:56 [main] DEBUG org.pf4j.DefaultPluginFactory - Create instance for plugin 'org.pf4j.demo.welcome.WelcomePlugin'
22:31:56 [main] INFO org.pf4j.demo.welcome.WelcomePlugin - WelcomePlugin.start()
22:31:56 [main] INFO org.pf4j.AbstractPluginManager - Start plugin 'hello-plugin@0.0.1'
22:31:56 [main] DEBUG org.pf4j.DefaultPluginFactory - Create instance for plugin 'org.pf4j.demo.hello.HelloPlugin'
22:31:56 [main] INFO org.pf4j.demo.hello.HelloPlugin - HelloPlugin.start()
pf4j-shell> plugins 
            Id|Version|  State
--------------+-------+-------
welcome-plugin|  0.0.1|STARTED
  hello-plugin|  0.0.1|STARTED

Stop all plugins:

pf4j-shell> plugins stop 
Stop plugins ..
22:32:53 [main] INFO org.pf4j.AbstractPluginManager - Stop plugin 'hello-plugin@0.0.1'
22:32:53 [main] INFO org.pf4j.demo.hello.HelloPlugin - HelloPlugin.stop()
22:32:53 [main] INFO org.pf4j.AbstractPluginManager - Stop plugin 'welcome-plugin@0.0.1'
22:32:53 [main] INFO org.pf4j.demo.welcome.WelcomePlugin - WelcomePlugin.stop()
pf4j-shell> plugins
            Id|Version|  State
--------------+-------+-------
welcome-plugin|  0.0.1|STOPPED
  hello-plugin|  0.0.1|STOPPED

Get information about a plugin:

pf4j-shell> plugin hello-plugin
Id : hello-plugin
Version : 0.0.1
State : STOPPED
Path : plugins/pf4j-demo-plugin2-0.1.0-SNAPSHOT-all.jar
PluginClass : org.pf4j.demo.hello.HelloPlugin
Description : 
Provider : Decebal Suiu
License : 
Requires : *
Dependencies : []
ClassLoader : org.pf4j.PluginClassLoader@44ebcd03

Get plugins classloaders:

pf4j-shell> classloader plugins 
welcome-plugin -> org.pf4j.PluginClassLoader@661972b0
hello-plugin -> org.pf4j.PluginClassLoader@44ebcd03

Get plugin classloader information:

pf4j-shell> classloader urls hello-plugin 
file:/home/decebal/work/pf4j-shell/demo-dist/plugins/pf4j-demo-plugin2-0.1.0-SNAPSHOT-all.jar

pf4j-shell> classloader loadedClasses hello-plugin
[class org.pf4j.demo.hello.HelloPlugin]

Use TAB for command auto-competition. Exit from shell with Ctrl-D.

Demo

Demo applications are available in demo folder. It's the same demo application available in PF4J but with the Boot.java modified (shell injected).
Run demo using run-demo scripts (linux/windows).

Note: In demo application, by default the plugins are not loaded on startup, so you need to call plugins load to load the plugins.