Transcript Document

Eclipse
Paolo Gasti
The Problem
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There is the need for a new development
environment
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It has to help software designers and implementers
to do their jobs faster and easier
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There are so many approaches to software
development that no tool can be the solution
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We need to fill the blank left by tools such as Emacs
What is Eclipse?
Eclipse is more than a Java IDE…
“Eclipse is a kind of universal tool platform – an open
extensible IDE for anything and nothing in particular.”
– eclipse.org
“In many ways Eclipse is the Emacs for the 21st century.” –
Martin Fowler
The Way to Eclipse
1997
1998
1999
2000
2001
2002
2003
VisualAge/Java
VisualAge Micro edition
Eclipse
June
Tech
Preview
Oct
June
v. 1.0
v. 2.0
Nov
Open Source
announcement
March
v. 2.1
Design Goals
•
Provide an open platform for the construction of tools for
application development
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Support an unrestricted set of tool providers
•
Support tools to manipulate arbitrary content types (language
neutral)
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Seamless integration of tools within and across different
content types and tool providers
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Availability on a wide range of platforms
Plug-in Architecture Goals
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Easy to develop
– Java Development Tools + Plug-in development
environment
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Scale-up to hundreds of installed plug-ins
– It tries to reduce start-up time
– Out-of-the-shelf Eclipse consists of 80 plug-ins
– Lazy loading
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Easy to discover, install, and update
– install/update support
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Easy to manage an installation
– managed configurations
Why Open Source
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Many partners can contribute during all the life cycle of
a tool
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It provides less dependency on a single vendor
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Every partner can implement its own product without
the need to stipulate any contract with IBM
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The community can
– provide feedback to the developers
– submit patches
– answering user’s questions
Implications
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Vendors can concentrate on their own special
area of expertise providing higher value
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Improved integration of tools from multiple
vendors
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The interface can be customized to fit any
function, format or style
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Plug-ins can be free or commercial
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A flourishing business gravitates around
Eclipse (WebSphere etc…)
Eclipse Architecture
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Plug-in, the smallest unit of Eclipse function
Eclipse is a platform with a small runtime Kernel
and several layers of plug-in built on it
Platform
Extensible IDE
Plug-ins
Plug-ins
IDE
Runtime
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Everybody can be a tool smith
SWT (Standard Widget Toolkit) offers significant
advantages over AWT and Swing
Eclipse Architecture
PDE Core, PDE Build,
PDE UI
PDE
Compiler, Refactoring,
JDT UI, JDT Debug,…
JDT
Resources, Team, Debug,
Help, Update, SWT, UI,…
Platform
Java VM
SDK
Eclipse Architecture
Eclipse Platform
Java
Development
Toolkit
(JDT)
Help
Workbench
JFace
Team
SWT
Debug
Plug-in
Development
Environment
(PDE)
Your
Tool
Workspace
Update
Platform Runtime
Eclipse Project
Another
Tool
Their
Tool
Eclipse Platform Start Up
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Eclipse Platform Runtime handles start up
– Discovers plug-ins installed on disk
– Matches up extensions with extension points
– Builds global plug-in registry
– Caches registry on disk for next time
Eclipse Platform
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The Platform is divided into components
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The standard components, provided with the installation file
freely downloadable from eclipse.org, are
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Ant
Core
Platform CVS Integration
Platform help system
Support for Platform scripting
Integrated search facility
SWT (Standard Widget Toolkit)
Dynamic Update/Install Service
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Universal Compare
Release Engineering
Debug framework
Text editor framework
Platform user interface
WebDAV integration
Generic Team support
Plug-in Architecture
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Extension point - named entity for collecting
“contributions”
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Extension - a contribution
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Each plug-in
– Contributes to 1 or more extension points
– Optionally declares new extension points – programmers
can extend good plug-ins to fit their needs
– Depends on a set of other plug-ins
– Contains Java code libraries and other files
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Details spelled out in the plug-in manifest
– Manifest declares contributions
– Code implements contributions and provides API
Extension Points Principles
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Let others contribute to your contributions
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Lazy loading rule: load extensions only when they
are about to be called
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Contributions do not
– override existing behavior
– remove or replace existing component
– harm existing or future contributions
Extension configuration in XML
<plugin id=“org.eclipse.ui”>
<extension-point name=“Prefs" id=“preferencepages“ schema="schema/prefs.exsd"/>
…
</plugin>
Extension point
definition
<plugin id=“myPlugin”>
<extension point="org.eclipse.ui.preferencepages">
<page id=“com.example.myprefpage"
icon="icons/image.gif"
title=“My title"
class=“com.example.mywizard">
</page>
</extension>
…
</plugin>
Extension
contribution
Plug-in Manifest
<plugin
Plug-in identification
id = “com.example.tool“
version = “2.1.0”
name = “Example Plug-in Tool"
class = "com.example.tool.ToolPlugin">
Other plug-ins
<requires>
<import plugin = "org.eclipse.core.resources“ version=“2.0.0”/>
needed
<import plugin = "org.eclipse.ui“ version = “2.0.1”/>
</requires>
<runtime>
Location of plug-in’s code
<library name = “tool.jar"/>
</runtime>
<extension
Declare
point = "org.eclipse.ui.preferencepages">
<page id = "com.example.tool.preferences"
contribution
icon = "icons/knob.gif"
this plug-in makes
title = “Tool Knobs"
class = "com.example.tool.ToolPreferenceWizard“/>
Declare new extension point
</extension>
<extension-point
open to contributions from
name = “Frob Providers“
other plug-ins
id = "com.example.tool.frobProvider"/>
</plugin>
Contribution architecture
My Plug-in
extension-point contributes
extension
imageFilters
ImageViewer Plugin
interface IImageFilter
implements
class GreyFilter
calls
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Declares extension point:
<extension-point
id=“imageFilters”/>
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Declares interface:
interface IImageFilter {
Image filter(Image image);
}
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Contributes extension:
<extension point=“….imageFilters”/>
…class=“GreyFilter”
</extension>
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Implements interface:
class GreyFilter implements
IImageFilter {
}
Contribution architecture
ImageViewer Plugin
extension-point
imageFilters
My Plug-in
contributes
extension
implements
interface IImageFilter
calls
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Declares extension point:
<extension-point
id=“imageFilters”/>
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Declares interface:
interface IImageFilter {
Image filter(Image image);
}
class GreyFilter
uses
Instantiated via reflection
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Contributes extension:
<extension point=“….imageFilters”/>
…class=“GreyFilter”
</extension>
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Implements interface:
class GreyFilter implements
IImageFilter {
}
Plug-in Activation
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Each plug-in gets its own Java class loader and has its
own class path
– Delegates class load requests to required plug-ins
requires
Java UI
requires
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requires
Java Core
requires
UI
Resources
requires
Contributions processed without plug-in activation
– Example: Menu constructed from manifest info for
contributed items
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Plug-ins are activated only as needed
– When a class is loaded by the class loader
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Scalable for large base of installed plug-ins
More than a Java IDE
Eclipse vs. NetBeans
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Languages
– C#
– C/C++
– Python
– Cobol
– Php
– Several UML
Programming Tools
– ANTLR Parser Generator
– Graphical Editing Framework (GEF)
– AspectJ tools
– Modeling (EMF)
– Several DB tools
– Jalopy Java Source Code Formatter
– Japple – RAD
– Jasper report designer
– Lomboz
– Java Spider
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Source & configuration mgt.
– Perforce
– Microsoft VSS Plug-in
– Clearcase
– Stellation
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Web development
– Sysdeo - Eclipse Tomcat Launcher
– WebLogic manager
– Several Struts
– Spindle for Tapestry
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Testing / Performance
– Resin Plug-in
– MockCreator
– Solex
– Hyades
http://www.eclipse.org/community/plugins.html
The UML 2 plug-ins
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There are several UML 2 compliant plug-ins
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Most of them provide support for
– Reverse-engineering of source code (often also from
binaries)
– Code generation
– Code Synchronization
– Code analysis
– Documentation generation
– Automatic diagram altering after code altering
Slime UML 2 plug-in
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Guides the team through all the development
process
It is very light-weight: only 1 MB
Refactoring Support
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Refactoring is changing the structure of a program
without changing its functionality
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There are many reasons to do refactoring
– The team of a project disappears and you need to
add/improve the functionality of its (quite obscure)
code
– A new requirement is introduced because of a design
mistake or an iterative approach (such as XP)
– Once familiar with this tool, a programmer can
generate code in the first place, then use it to conform
its code to some standards (such as the use of
getter/setter methods)
Refactoring Support
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Eclipse provides three types of Refactoring
– Physical organization and renaming
– Logical organization at the class level
– Change the code within a class
Physical organization and renaming
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Avoid the need to edit many files to update import
and package statements
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Automatically checks the context, not only the
names
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Allows to automatically
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Rename fields
Rename variables
Rename classes and interfaces
Move packages and classes
Logical organization at the class level
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While not as useful as the other kind of refactorings,
it allows to automatically
– Turn anonymous classes into nested classes
– Turn nested classes into top-level classes
– Create interfaces from concrete classes
– Move methods or fields from a class to a subclass or
superclass
Change the code within a class
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Allows you to automatically
– Turn local variables into class fields
– Turn selected code in a method into a separate
method
– Generate getter and setter methods for fields
– Change method signature (doesn’t fit exactly here…)
Refactoring Support
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The power of Eclipse’s refactoring capability is to
allow an user to do a safe refactoring with some
mouse clicks
Eclipse’s Cons
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Windows-centric (ActiveX, OLE)
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Slow and often unstable under Unix
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Forces developers to use its own directory
structure
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Sun does not like it exists, having its own
NetBeans (but Eclipse is supported by
IBM…)
Case of Study: the JavaCard Plug-in
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It offers the complete class library of the JavaCard
platform
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Allows developers to simulate IBM’s smart card
hardware
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Offers an advanced debugger
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Lets Eclipse connect to real smart cards
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Offer complex functionalities
Case of Study: the JavaCard Plug-in
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Offers concrete advantages against the stand-alone
version
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The Java Editor provided with Eclipse is much better
than the editor provided with JavaCard
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Allows the developer to edit and test the code with
the same interface
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Can be used together with other tools such us an
UML 2 plug-in
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Shows the power of the Eclipse platform when
developing highly specialized software
Summary
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All functionality is provided by plug-ins and
fragments
– Includes all aspects of Eclipse Platform itself
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Contributions are made via extension points
– Extensions are created lazily
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Plug-ins are packaged into separately installable
features
– Downloadable
Summary
 Everybody can contribute plug-ins
 Every programmer can be a tool smith
 Creating opportunities for further extension makes
it possible for the tool smith to benefit from the
work of others
 The same environment can be used to develop
applications and to develop tools for itself
References
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Refactoring For Everyone by IBM (http://www106.ibm.com/developerworks/opensource/library/osecref/)
Eclipse Platform Technical Overview – eclipse.org
The Mathaino Project - Department of Computing
Science, University of Alberta
Eclipse Platform on-line help
Omondo whitepaper – www.omondo.com
Eclipse.org plug-ins documentation http://www.eclipse.org/community/plugins.html
OOPSLA 2003 documentation – www.oopsla.org