CRaSH: the shell for the Java Platform

CRaSHT H E S H E L L F O R T H E J AVA P L AT F O R M

S E P T E M B E R 2 0 1 3

@julienviet@defrancea

www.exoplatform.com - Copyright 2012 eXo Platform 2

JULIEN VIET

−Contact

− [email protected]−@julienviet−http://github.com/vietj

−Open source for 10 years

−Official mission: deliver enterprise grade portal server

−Marseille JUG Leader

−Involved in Java Community Process

http://github.com/vietj


WHAT IS EXO PLATFORM?

eXo Platform is an open source social collaboration software solution designed for the Enterprise.

It is full featured, standard based, extensible and has an amazing design.

eXo Platform is featured in Gartner's Magic Quadrant for Horizontal Portal Products 2012 as a User eXperience Platform.


ALAIN DEFRANCE

−Contact

−[email protected]−@alaindefrance−http://github.com/defrancea

−Open source for 3 years

−Contributed to open source projects like Crash

−Marseille JUG Leader


BITTITAN

−SAAS Products

−MigrationWiz: Email migration−SMTPLogic: SMTP gateway−UserActivation: Easy onboarding to

Office365

−Our blog−http://blog.bittitan.com


CRASH PROJECT

−Latest stable 1.2

−Work in progress 1.3

−Licensed under LGPL

−Compatibility

−Java 6+−Groovy 1.7+


KEY CONCEPTS

−Command Line Interface for JVM

−Create easily and quickly commands

−Compose commands into pipelines

−Connectors provide local or remote access


MODULAR DESIGN

−Core, connectors, plugins

−Only use what you need

−Memory−Dependencies


CONNECTORS

−Defines shell interactions

−Asynchronous design

−Implemented by

−System.in / System.out−Telnet−SSH−Web−Attach


PLUGIN ARCHITECTURE

−Keep core small and lightweight

−New features without impacting core

−Current plugins

−Authentication: simple, jaas, key, crowd, …−Languages: java, groovy, ruby, …−Services: mail, cron, …


USER INTERFACE

−Interactive Real-Eval-Print-Loop

−SSH asynchronous execution

−Cron based execution (1.3)


POLYGLOT

−Leverage polyglot JVM ecosystem

−Groovy

−Commands−REPL (1.3)

−Java

−Commands (1.3)

−Ruby work in progress


EXECUTION MODES

−Standalone

−Attach to a running JVM

−Embedded

−Servlet listener−Spring−Guice−Grails−VisualVM


BASE COMMANDS

−Covers JVM packages

−system−jdbc−jndi−jmx

−Utilities: filter, sort, egrep, sleep


STANDALONE DEMO


JNDI/JDBC/JPAATTACH

DEMO


WRITING A COMMAND

public class mycommand {

@Command

@Usage(“the command”)

public void main(

@Usage(“foo option”)

@Option(names=[ “foo”]) String foo,

@Usage(“command arguments”)

@Argument List<String> args) {

…

}

}

% mycommand –foo the_option value1 value2


EMBEDDED

−Trivial to embed

−Programmatic−Spring−Guice−Servlet listener

−Levels

−Embed−Virtual file system


EMBEDDED BY


SPRING EMDEDDEDTWITTER COMMAND

DEMO


GIT LIKE COMMAND

public class git { @Command public void add(…) {…}

@Command public void commit(…) {…} …}

% git add .% git commit –m “feature implemented”


TYPES

−String, primitive types, enums

−Converter

−properties, jmx object name …

−Completer

−java.io.File−system property name−enums−…


COMMAND PIPE

% jmx find …

jmx find

ObjectName Map

jmx get

sort


COMMAND PIPE

public class wc {

@Command

public PipeCommand<String, Integer>) main() {

return new PipeCommand<String, Integer>() {

int count = 0;

public void provide(String s) {

count += s.split(“\n”).length;

}

public void close() {

context.provide(count);

}

}

}

}


JMX PIPE DEMO


MAIL/CRONDEMO


READ-EVAL-PRINT-LOOP

−Feature of 1.3

−Polyglot


REPLDEMO


WRAP UP

−A multi facet, powerful and extensible tool for all of us

−Try online : try.crashub.org

−Reach us at

−crashub.org−@crashub−[email protected]

mailto:[email protected]

CRaSH: the shell for the Java Platform

Technology

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