Lucy

A micro HTTP framework based on Netty for Java.

Requirements

• JDK8+
• Eclipse

Maven

<dependency>
  <groupId>com.pr-ing</groupId>
  <artifactId>lucy</artifactId>
  <version>$VERSION</version>
</dependency>

Getting Started

• Define an entry point:

package entry;

import org.pring.lucy.server.Server;

public class Main extends Server {
  public static void main(String[] args) throws Exception {
    new Main()
      // .withoutCookies()
      // .sessionAge(60)
      // .gzip()
      // .database("jdbc:mysql://localhost:3306/information_schema", "root", "root")
      // .production()
      .staticLocation("/var/www")
      .port(8080)
      .serve();
  }
}

• Define a handler class:

package root.controller;

import org.pring.lucy.server.HttpController;

public class Index extends HttpController {
  @Override
  public void index() throws Exception {
    echo("Hello World");
  }
}

• Test it:

http://localhost:8080/
- or -
http://localhost:8080/index
- or -
http://localhost:8080/:index/index
- or -
http://localhost:8080/root:index/index
                      ^    ^     ^
                      |    |     method name
                      |    class name
                      package name

Create a root.view package and a matching html template in it if you want templating. So if you have Index.java you must have index.html (lowercase) in root.view.

/ -> binds to root.*

Configuration

...
    new Main()
      //  1. withoutCookies()
      //  2. sessionAge(60)
      //  3. gzip()
      //  4. database("jdbc:mysql://localhost:3306/information_schema", "root", "root")
      //  5. production()
      //  6. staticLocation("/var/www")
      //  7. port(8080)
      //  8. epoll()
      //  9. sync()
      // 10. mqtt(broker, listener, topic)
      // 11. serve();
...

• withoutCookies()
  Will not set any cookies at all. In case you have a static website.
• sessionAge(60)
  Defines session age in seconds.
• gzip()
  Will gzip the response sent to client.
• database("jdbc:...", "user", "pass")
  Will initiate a database pool.
• production()
  Will load the clases only once. No hot reloading. It must be uncommented when exporting to final JAR.
• staticLocation("absolute path")
  Sets the location of static files.
• port(8080)
  Sets the port where to listen.
• epoll()
  Enables native Linux epoll.
• sync()
  Joins the main thread and blocks. Omit this if you have anything else after (which of course blocks main thread).
• mqtt(broker, listener, topic)
  Connects to a specified broker and handles incoming messages through a MqttCallbackListener coming to subscribed topic. Use # as a wild card. publish(topic, message) will publish your messages from any controller.
• serve()
  Kicks off everything.

Features

• Hot reloading
• Templating
• Sessions
• Database
• Very simple interface
• Lightweight and somewhat fast

Methods

Method	Function
redirect(to)	Redirects to specified URL
redirectWithTemplate(to, templateName)	Redirects to specified URL and sets a desired template
status(code)	Sets HTTP status code, overrides @Status annotation
method()	Returns request HTTP method
halt()	Halts execution
halt(status)	Halts execution with status code
halt(status, message)	Halts execution with status code and a message
header(name)	Gets header name from request
header(name, value)	Sets a header on response
headers()	List of request headers
cookie(name)	Gets cookie name
cookie(name, value)	Sets cookie value to name on response
cookie(name, value, ttl)	Sets cookie value and age to name on response
cookie(name, value, ttl, isSecure)	Sets cookie value and age and security to name on response
cookie(name, null)	Removes cookie
cookies()	Gets cookie list
queryParams(key)	Gets a query param List for key
GET(key)	Gets a String value for key
GETint(key)	Gets an int value for key
GETdouble(key)	Gets a double value for key
POST(key)	Gets a String value for key
POSTint(key)	Gets an int value for key
POSTdouble(key)	Gets a double value for key
session(key)	Gets session value for key
session(key, value)	Sets session value for key
session(key, null)	Removes key from session
session()	Gets a key, value Map
sessionId()	Gets session id
sessionDestroy()	Destroys session
echo(msg)	Echoes stuff
debug(msg)	Prints stuff on running terminal
view(key, value)	Passes key and value to template
template(name)	Easy template selection (overrides @View(name))
file(name)	Gets File from uploaded file
files()	Gets a List with uploaded Files
sendFile(path)	Forces browser to download given file from path
sendFile(data[], name)	Creates a temporary file from data and sends to client
clientIp()	Gets client IP
port()	Gets client port
requestMethod()	Gets HTTP request method
url()	Gets request URL
userAgent()	Does not work
isKeepAlive()	Gets connection type
SqlDB.query("QRY")	Returns a one row CachedRowSet. Use this if you're not going to loop through results
SqlDB.query("QRY", args)	Returns a one row CachedRowSet. Use this if you're not going to loop through results
SqlDB.selectCell("QRY")	Returns one row with one cell
SqlDB.selectCell("QRY", args[])	Returns one row with one cell
SqlDB.select("QRY")	Returns an Iterable so you can loop through it
SqlDB.select("QRY", args)	Returns an Iterable so you can loop through it
SqlDB.insert("QRY", args)	Returns mysql-last-id
SqlDB.update("QRY", args)	Returns manipulated row nums
SqlDB.delete("QRY", args)	Returns manipulated row nums (Alias to .update)
publish(topic, message)	If mqtt is called on Main then this will publish a message to a desired topic.
broadcast(message)	If you have a @WebSocket method then this will broadcast a message to all active WebSocket channels.

Method Annotations

Annotation	Function
@API	Marks method as an API method and ignores templating
@API("text/plain")	Marks method as API and sets Content-Type and ignores templating
@NoSession	Does not bother with session stuff
@Status(200)	Sets HTTP response code
@View("index1")	Sets a custom view
@View("")	Removes associated template
@NoAccessCheck	Does not check hasAccess() which returns boolean, for e.x: isLoggedIn
@WebSocket	Marks method as WebSocket handler

Examples

Say you have an API with buyer and seller. You can have the code separately like this:

buyer.controller.*
buyer.view.*
- and -
seller.controller.*
seller.view.*

buyer.controller.Index:

package buyer.controller;

import org.pring.lucy.server.HttpController;

public class Index extends HttpController {
  @Override
  public void index() throws Exception {
    view("myVar", aVeryComplexCalculation());
  }
  
  private static int aVeryComplexCalculation() {
    return 42;
  }
}

buyer.view.index:

<B> {{ $myVar; }} </B>

Then access it like this:

http://localhost:8080/buyer:/

seller.controller.Index:

package seller.controller;

import org.pring.lucy.server.HttpController;

public class Index extends HttpController {
  @Override
  @API
  public void index() throws Exception {
    for (ResultSet r : SqlDB.select("select * from `sellers`;")) {
      echo(r.getString("id") + " => " + r.getString("name") + '\n');
    }
  }

  @API
  public void update(int id, String name) {
    SqlDB.update("UPDATE `sellers` SET `name` = ? WHERE `id` = ?", new Object[] { name, id });
    redirect("/");
  }
}

Then access it like this:

http://localhost:8080/seller:/

Or update like this:

http://localhost:8080/seller:index/update/1/Awesome
                      ^      ^     ^      ^ ^ 
                      |      |     |      type safe args: id/name
                      |      |     method name
                      |      class name
                      package name

Arguments are typesafe, so if you try to pass a String where int is expected, you'll get an exception if you're under development mode, otherwise it will politely redirect you to /.

Template Engine

Template engine is pure Java code plus for a short hand when writing for loops:

<ul>
{{
  for (String s : String[] { "first" }) {
    <li>$s;</li>
  }
}}
</ul>

... and include:

{{ include $myTemp; }}
- or -
{{ include "some.other.package.file" }}
- or -
{{ include "someOtherFile" }}
- or -
{{ include "/var/www/file/on/disk.html" }}

Database access obviously:

<ul>
{{
  for (ResultSet r : SqlDB.select("select * from `sellers`;")) {
    <li>$r.getString(1);</li>
  }
}}
</ul>

Also Session through a session variable:

I'm  {{
  if (session.getBoolean("isLoggedIn"))
    echo("<b>logged in. WOHOOOO</b>");
  else
    echo("<i>OUT :(</i>");
}}

Roadmap

• Maven
• WebSockets
• Spdy
• MQTT
• Some Optimizations
• Writing code with Xtend

Download

https://github.com/betim/Lucy/releases/tag/1.1

Dependencies

• Netty 4.0.37.Final
• commons-lang3 3.4
• HikariCP 2.4.6
• slf4j-api 1.7.21
• mysql-connector-java 5.1.36
• org.eclipse.paho 1.0.2

---

• Currently works only on Unix/Linux.

License

Copyright 2015 Lucy

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.