title: Keep it Simple - Embedded Jetty, Embedded SQLite, Embedded Ruby
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Friends of Ruby (Rails)? - Anyone?
-
Friends of Server-Side JavaScript (Node.js) - Anyone?
-
Friends of Functional Programming (Haskell, Yesod) - Anyone?
-
Friends of Scala, Play! - Anyone?
-
Friends of Dart - Anyone?
-
Friends of CSS Preprocessors (Less, Sass) - Anyone?
| 1) | No Enterprise Java Application Server | => | Use Embedded Jetty Library to Run Container-Less |
| 2) | No Enterprise Java Database Server | => | Use Embedded SQLite Library |
| 3) | No Enterprise Java Application Framework | => | Use Embedded Ruby Library |
| 4) | No Enterprise Java IDE | => | Use Command Line, Programmer's Editor |
Notes
- SQLite - Zero-Configuration; Q: What's the world's most popular DB?
[ ] Factories, Factories, Factories
[ ] The COBOL of the 21st Century
[ ] Keep it Simple
[ ] There is only Java, Java, Java - 1,000,0000,000 % Java
[ X ] |
Factories, Factories, Factories |
| Yes! => Over-engineering, Cult of Complexity | |
[ X ] |
The COBOL of the 21st Century |
| Yes! => Old technology, No Longer Hot Java or the New New Thing, | |
| Innovation Happens Elsewhere | |
[ ] |
|
| Ha! | |
[ X ] |
There is only Java, Java, Java - 1,000,0000,000 % Java |
| Yes! => The End of History, Java Rules the World Hybris |
Hybris (Definiton from Wikipedia):
extreme arrogance; often indicates a loss of contact with reality and an overestimation of one's own competence or capabilities, especially when in a position of power.
Step 1: Copy jetty-webapp-7.x.jar (~ 1 Meg)
Step 2: There is no step 2.
Container-Less? Run your web application as a plain old Java process.
Why:
- Simpler Development
- Simpler Testing
- Simpler Packaging
- Simpler Deployment
The simplest possible Jetty server:
import org.eclipse.jetty.server.Server;
public class SimpleServer
{
public static void main(String[] args) throws Exception
{
Server server = new Server(8080);
server.start();
server.join();
}
}
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.webapp.WebAppContext;
public class AppServer
{
public static void main(String[] args) throws Exception
{
Server server = new Server(8080);
WebAppContext webapp = new WebAppContext();
webapp.setContextPath("/");
webapp.setWar( "./links.war");
server.setHandler(webapp);
server.start();
server.join();
}
}
javac -cp .;./jetty-webapp-7.x.jar AppServer.java
- Post links
- Vote links up or down
- Sort links by the newest or hot
$ rails links
create_table :links do |t|
t.string :title, :null => false
t.string :url, :null => false
t.integer :points, :default => 0
t.timestamps # note: macro adds created_at, updated_at
end
$ rake db:setup # note: rake is ruby make (simple build tool)
class Link < ActiveRecord::Base
# self.table_name = 'links'
attr_accessor :score
def recalc_score
time_elapsed = (Time.now - self.created_at) / 36000 # in hours
self.score = ((self.points-1) / (time_elapsed+2)**1.8)
end
def self.hot
self.all.each { |rec| rec.recalc_score }.sort { |l,r| l.score <=> r.score }.reverse
end
end
class LinksController < ApplicationController
# GET /
def index
@links = Link.order( 'created_at desc' ).all
end
# GET /hot
def hot
@links = Link.hot
render :index
end
# POST /
def create
l = Link.new( params[:link] )
l.save!
redirect_to :back
end
# PUT /:id/vote/:type
def vote
l = Link.find( params[:id] )
l.points += params[:type].to_i
l.save!
redirect_to :back
end
end
<table id='links'>
<%% @links.each do |l| %>
<tr>
<td class='points'>
<%%= form_for l, :url => vote_link_path( l, :type => '1' ), :method => 'PUT' do |f| %>
<%%= f.submit '+1' %>
<%% end %>
<%%= l.points %>
<%%= form_for l, :url => vote_link_path( l, :type => '-1' ), :method => 'PUT' do |f| %>
<%%= f.submit '-1' %>
<%% end %>
</td>
<td><span class='title'><%%= link_to l.title, l.url %></span>
<span class='host'>(<%%= l.url_host %>)</span>
<span class='created-at'>posted <%%= time_ago_in_words(l.created_at) %> ago</span>
</td>
</tr>
<%% end %>
</table>
<div id='post-link'>
<%%= form_for :link, :url => links_path() do |f| %>
<%%= f.text_field :title, :placeholder => 'Title' %>
<%%= f.text_field :url, :placeholder => 'URL' %>
<%%= f.submit 'Save Link' %>
<%% end %>
</div>
$ rake war # warble
$ java -cp .;./jetty-webapp-7.x.jar AppServer
=> One Plain Old Java Process - Embedded Jetty, Embedded SQLite, Embedded Ruby
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Java Runtime Coded in C Code
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Ruby Runtime Coded in Java Code
"When all you have is a hammer, everything looks like a nail."
"Java is like violence -- if it doesn't solve your problems, you are not using enough of it."
Step 1: Copy jruby-complete-1.7.x.jar
Step 2: There is no step 2.
links.war
|_ images
| | _<empty>
|_ stylesheets
| |_ application.css
|_ javascripts
| | _<empty>
|_ WEB-INF
|_ app
| |_ controllers
| | |_ links_controller.rb
| |_ models
| | |_ link.rb
| |_ views
| |_ layouts
| | |_ application.html.erb
| |_ links
| |_ index.html.erb
|_ config
| |_ database.yml
| |_ routes.rb
|_ db
| |_ links.sqlite3
|_ lib
|_ jruby-complete-1.7.x.jar
|_ jruby-rack-1.x.jar
|_ gems.jar
[ ] Water
[ ] Cola Sugar Syrup
[ ] Malt
[ ] Hops
[ ] Whiskey
[ X ] Water - Yes!
[ ] Cola Sugar Syrup - No!
[ X ] Malt - Yes!
[ X ] Hops - Yes
[ ] Whiskey - No!
[ ] Hypertext Markup Language (HTML)
[ ] COBOL
[ ] Cascading Style Sheets (CSS)
[ ] Java
[ ] JavaScript (JS)
[ X ] Hypertext Markup Language (HTML)
[ ] COBOL - No!
[ X ] Cascading Style Sheets (CSS)
[ ] Java - No!
[ X ] JavaScript (JS)
Anyone?
Example:
{ customer:
{ id: '12345',
first_name: 'Carlos',
last_name: 'Lafata',
address:
[
{ typ: 'home',
line1: 'Burgring 11',
city: 'Wien',
zip_code: '1010' },
{ typ: 'work',
line1: 'Nestroyplatz 12',
city: 'Wien',
zip_code: '1020' }
] }
}
[ X ] JavaScript
[ X ] Ruby
[ X ] Scala
[ ] Java
[ ] COBOL
Example:
// Assign Function to Variable
var greet = function() { document.write( 'Welcome. Benvenuti. Willkommen.' ); }
// Call Function Stored in Variable
greet();
// Function as Function Parameter
function say( what )
{
what();
what();
what();
}
// Pass Function Stored in Variable to Function
say( greet );
[ X ] JavaScript
[ X ] Ruby
[ X ] Scala
[ ] Java
[ ] COBOL
- Don't put yourself in the Java ghetto (or Java rules the world hybris)
=> Learn new concepts or languages
- Web architecture is more than Java enterprise architecture
=> Learn HTML, JS, CSS, HTTP (REST), SQL/NoSQL, etc.
Write Once, Runs Anywhere
JavaScript
- runs in the browser? Yes!
- on the server? Yes!
- has many industry-strength open source runtimes? yes!
- not owned/controlled by single-vendor? yes!
- runs as fast as C? yes!
- can run cross-compiled C/C++ code? yes!
- has first-class functions? yes!
- ships builtin for Windows by Microsoft? yes!
- works on the iPhone, iPad? yes!
Open Source PDF Reader in JavaScript; runs in your browser; ships with Firefox 15+ (no more plugin required; it's JavaScript!)
mozilla.github.com/pdf.js
LLVM to JavaScript Compiler
Step 1: Compile C Code to LLVM Bitcode (with clang)
Step 2: Compile LLVM Bitcode to JavaScript (with Emscripten)