Monday, 15 July 2013

Java logback + slf4j instead of log4j + slf4j


Inspiration 
1 - 10 Reasons to switch to logback
2 - LOGBack: Evolving Java Logging
3 - Clean code, clean logs: easy to read, easy to parse (10/10) Series, (Tomasz Nurkiewicz, 2010)




[STEP 1] add slf(Simple Logging Facade)4j and logback dependencies


<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.6.6</version>
</dependency>

<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.0.9</version>
</dependency>


[STEP 2] configure logback.xml to src/main/resources
Don't forget to add <appender> to <root>, each appender thus referenced is added to the <root> logger.


logback.xml would look like the folloing one.

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <!--
        WARN or higher goes to STDOUT (catalina.out)
    -->
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
   <encoder>
     <pattern>
        %d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
      </pattern>
    </encoder>
</appender>


<appender name="eccountFileAppender"

class="ch.qos.logback.core.rolling.RollingFileAppender">

<file>${catalina.base}/logs/eccount.log</file>
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<Pattern>%d{yyyy-MM-dd_HH:mm:ss.SSS} [%thread] %-5level %logger{36} -
%msg%n
</Pattern>
</encoder>

<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">

<fileNamePattern>${catalina.base}/logs/eccount.%d{yyyy-MM-dd}.%i.gz
</fileNamePattern>
<timeBasedFileNamingAndTriggeringPolicy
class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<maxFileSize>100MB</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
<maxHistory>10</maxHistory>
</rollingPolicy>
</appender>



<!-- additivity=false ensures eccountlog data only goes to the analytics log -->
<logger name="eccountlogger" level="ALL" additivity="false">
        <level value="INFO"/>
<appender-ref ref="eccountFileAppender" />
</logger>


<root level="INFO">
<appender-ref ref="STDOUT" />
<appender-ref ref="eccountFileAppender" />
</root>

</configuration>



[STEP 3] implement org.slf4j.Logger

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class RequestManager implements IRequestManager, MessageSourceAware {
       private static Logger logger =          LoggerFactory.getLogger("eccountlogger"); //log will then reflected to its corresponding <appender-ref/>
  
  @override
  public void process(){
      logger.error("This is my {}", new Object[]{ arg, e});
  }
}


References
SLF4J with Logback in a Maven Project, http://blog.mograbi.info/2013/03/slf4j-with-logback-in-maven-project.html

Logback using SLF4J Hello World Example, http://www.srccodes.com/p/article/21/logback-using-slf4j-hello-world-example

http://stackoverflow.com/a/2489569/432903

http://itsmevandana.wordpress.com/2012/12/27/setting-up-logging-in-an-web-based-application-using-logback-xml/

http://stackoverflow.com/questions/13685084/grails-2-1-1-logback-integration/

Friday, 12 July 2013

Hacking on rails 3.2.8 and mysql



Create a rails app called Gwitter at any location you want. Change directory to the same rails app and follow the STEPS as below.

[STEP 1] add mysql dependency to Gemfile and then fire bundle install
prayag@prayag:~/workspace_rails/Gwitter$ vi Gemfile
 gem 'mysql', '2.8.1'

prayag@prayag:~/workspace_rails/Gwitter$ bundle install


find gem INSTALLATION DIRECTORY
prayag@prayag:~/workspace_rails/Gwitter$ gem env
RubyGems Environment:
  - RUBYGEMS VERSION: 1.8.24
  - RUBY VERSION: 1.9.3 (2012-10-12 patchlevel 286) [i686-linux]
  - INSTALLATION DIRECTORY: /home/prayag/.rvm/gems/ruby-1.9.3-p286
  - RUBY EXECUTABLE: /home/prayag/.rvm/rubies/ruby-1.9.3-p286/bin/ruby
  - EXECUTABLE DIRECTORY: /home/prayag/.rvm/gems/ruby-1.9.3-p286/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - x86-linux
  - GEM PATHS:
     - /home/prayag/.rvm/gems/ruby-1.9.3-p286
     - /home/prayag/.rvm/gems/ruby-1.9.3-p286@global
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/
   
gems installed can be checked with following command, 

prayag@prayag:~/workspace_rails/Gwitter$ ls -l /home/prayag/.rvm/gems/ruby-1.9.3-p286/gems/
total 156
drwxrwxr-x  3 prayag prayag 4096 Oct 30 12:08 actionmailer-3.2.8
drwxrwxr-x  3 prayag prayag 4096 Oct 30 12:07 actionpack-3.2.8
drwxrwxr-x  3 prayag prayag 4096 Oct 30 12:07 activemodel-3.2.8                 
drwxrwxr-x  4 prayag prayag 4096 Oct 30 12:08 activerecord-3.2.8                
[...]
drwxrwxr-x  7 prayag prayag 4096 Nov 25 16:49 mysql-2.9.0
[...]drwxrwxr-x  2 prayag prayag 4096 Oct 30 12:09 rails-3.2.8
drwxrwxr-x  5 prayag prayag 4096 Oct 30 12:09 railties-3.2.8
[...]


OR simply with,
prayag@prayag:~/workspace_rails/Gwitter$ gem list

*** LOCAL GEMS ***


actionmailer (3.2.8)
actionpack (3.2.8)
activemodel (3.2.8)
activerecord (3.2.8)
activeresource (3.2.8)
activesupport (3.2.8)
arel (3.0.2)
builder (3.0.4)
bundler (1.2.1)
[...]
rails (3.2.8)
railties (3.2.8)
rake (0.9.2.2)
[...]


[STEP 2] configure config/database.yml for mysql
# SQLite version 3.x
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
development:
  adapter: mysql
  username : eccount
  password:eccount
  host: 10.13.212.4
  database: BadalKarkhana
  pool: 5
  timeout: 5000

# Warning: The database defined as "test" will be erased and

# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:

  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000



[STEP 3] scaffold(resource) User
Following command will generate CRUD  files for a model User, 
 

prayag@prayag:~/workspace_rails/Gwitter$ rails generate scaffold User firstName:string lastName:string active:boolean


[STEP 4] migrate database using rake
prayag@prayag:~/workspace_rails/Gwitter$ bundle exec rake db:migrate
==  CreateUsers: migrating ====================================================
-- create_table(:users)
   -> 0.1665s
==  CreateUsers: migrated (0.1666s) ===========================================


   
References
[1] 5 Getting Up and Running Quickly with Scaffolding, http://guides.rubyonrails.org/getting_started.html

[2] My five favorite “hidden” features in Rails 3.2, http://blog.plataformatec.com.br/2012/01/my-five-favorite-hidden-features-in-rails-3-2/

[3] Learn Web Development with Rails, http://ruby.railstutorial.org/chapters/a-demo-app#top