July 20, 2009

Eclipse Templates

Templates are a usefull thing when working with code as we know.
A simple template is a simple thing to do but using an import is a different beast.

so here is a example to make sure that the import is also included in the java file.

/** Tapestry render phase method. Called before component body is rendered.*/
public void beforeRenderBody(){

May 21, 2009


Most applications using ORM tooling have need of a transaction management system.
One of these transaction managers is Atomikos. Atomikos provides several products. One transaction essentials is an opensource variant.
However you cannot get it via a maven repository. You'll have to register for a download link.
Transaction essentials is easy embeddable within a jetty container or even within a spring context.

First here's how to implement transaction essentials within a jetty container configured with maven.

Lets start with the jetty configuration within a maven pom file:

<!-- Run the application using "mvn jetty:run" -->
                    <!-- Log to the console. -->
                    <requestLog implementation="org.mortbay.jetty.NCSARequestLog">
                        This doesn't do anything for Jetty, but is a workaround for a
                        Maven bug that prevents the requestLog from being set.

The jettyConfig tx-jetty contains the configuration for the atomikos usertransactionmanager and will be applied before other setting set in the maven pom:

<Call class="java.lang.System" name="setProperty">

   <!-- Atomikos -->
   <New id="tx" class="org.mortbay.jetty.plus.naming.Transaction">
         <New class="com.atomikos.icatch.jta.UserTransactionImp" />

The jetty-env contains the configuration for a specif webapplication in jetty and consists in part of the datasources for the webapp:

<Set name="configurationClasses">
    <Array type="java.lang.String">
  <!-- Add a mapping from name in web.xml to the environment -->
  <New id="map1" class="org.mortbay.jetty.plus.naming.Link">
    <Arg><Ref id='rbudisplay'/></Arg>
    <Arg>jdbc/rbuconverter</Arg> <!-- name in web.xml -->
    <Arg>jdbc/rbu</Arg>  <!-- name in environment -->
  <New id="rbuconverter" class="org.mortbay.jetty.plus.naming.Resource">
     <Arg><Ref id="rbudisplay"/></Arg>
      <New class="com.atomikos.jdbc.AtomikosDataSourceBean">
       <Set name="minPoolSize">2</Set>
       <Set name="maxPoolSize">50</Set>
       <Set name="xaDataSourceClassName">org.postgresql.xa.PGXADataSource</Set>
       <Set name="UniqueResourceName">rbuconverter</Set>
       <Get name="xaProperties">
         <Call name="setProperty">
         <Call name="setProperty">
         <Call name="setProperty">
         <Call name="setProperty">
         <Call name="setProperty">

The first part sets up the jetty plus environment for jndi.
The second part sets up the reference for the jetty-env configuration and to bind the datasource to jndi so the web.xml can make a refernce to the configured datasource.
The third part sets up the datasource itself. Here an XADataSource is configured for PostgreSQL Note that the com.atomikos.jdbc.AtomikosDataSourceBean is the prefered DataSource since Atomikos 3.4.x.

The web.xml needs to have these lines in place for the above configured datasource:


It is also possible to configure Atomikos transaction Essentials completely in a spring context. In this case do not use the jettyConfig and jettyEnvXml in the pom file and omit the resource-ref within the web.xml:
I have a tx-context.xml:

<bean class="com.atomikos.jdbc.AtomikosDataSourceBean" destroy-method="close" id="dataSource" init-method="init">
        <property name="uniqueResourceName" value="rbudatasource"/>
        <property name="xaDataSourceClassName" value="org.postgresql.xa.PGXADataSource"/>
        <property name="xaProperties">
              <prop key="databaseName">rbuconverter</prop>
              <prop key="serverName">localhost</prop>
              <prop key="portNumber">5432</prop>
              <prop key="user">postgres</prop>
              <prop key="password">BlahBlah</prop>
        <property name="minPoolSize" value="5">
        <property name="maxPoolSize" value="50">

    <bean class="com.atomikos.icatch.config.UserTransactionServiceImp" destroy-method="shutdownForce" id="userTransactionService">
                <prop key="com.atomikos.icatch.service">
                <prop key="com.atomikos.icatch.output_dir">/tmp</prop>
                <prop key="com.atomikos.icatch.output_dir">/tmp</prop>
   <!-- Construct Atomikos UserTransactionManager, needed to configure Spring -->
   <bean id="AtomikosTransactionManager" class="com.atomikos.icatch.jta.UserTransactionManager" init-method="init" destroy-method="close" depends-on="userTransactionService">
      <!-- when close is called, should we force transactions to terminate or not? -->
      <property name="forceShutdown" value="false" />
      <property name="transactionTimeout" value="300"/>

   <!-- Also use Atomikos UserTransactionImp, needed to configure Spring -->
   <bean id="AtomikosUserTransaction" class="com.atomikos.icatch.jta.UserTransactionImp" />

   <!-- Configure the Spring framework to use JTA transactions from Atomikos -->
   <bean id="transactionManager" class="org.springframework.transaction.jta.JtaTransactionManager" depends-on="userTransactionService">
      <property name="transactionManager" ref="AtomikosTransactionManager" />
      <property name="userTransaction" ref="AtomikosUserTransaction" />

April 4, 2009

Tapestry activation passivation

Tapestry 5 can make use of the client to make information set to a page from another page available to the client.
For instance Page Origin places a message during a submit onto Page Next and using the mechanism of passivation and activation
the client will act as the middle man to make this information available to the client itself.
Tapestry will issue an HTTP 302 redirect after the post and thus the passivation of Page Next so the client recieves some information and will ask tapestry for that information to be acted upon.
Here you see that the value of 'Howdy' is submitted and using a redirect is send to the server again to be used in its activation event.

February 2, 2009

Apache2 VirtualHost and trac behind a lighttpd proxy

Note to self:
setup of trac for Apache2

follow this instructions on this site: Robert Basic: Trac on Ubuntu.
Although I use mercurial as scm.
make sure that the line containing VirtualHost points to port 81 or another port except port 80.

<VirtualHost *:81>
and make sure apache listens to this port by changing /etc/apache2/ports.conf
NameVirtualHost *:81
Listen 81

Now install lighttpd:

sudo apt-get install lighttpd

edit /etc/lighttpd/conf-available/10-proxy

$HTTP["host"] == "localhost" {
proxy.debug = 1
proxy.server     = ( "/trac" =>
                       ( "host" => "",
                         "port" => 81,
and symlink:
sudo ln -s /etc/lighttpd/conf-available/10-proxy /etc/lighttpd/conf-enabled/10-proxy

and start lighttpd
sudo /etc/init.d/lighttpd restart
et voilĂ 
the trac instance works both under localhost/trac as well as localhost:81/trac

January 5, 2009

Setting up my python development environment

Note to self:
my setup for a python development environment
sketch so far:

use virtualenv wrapper changed mkvirtualenv function to to virtualenvwrapper_bashrc
function mkvirtualenv () {
    (cd "$WORKON_HOME"; virtualenv $*)
    if [ ! -f $WORKON_HOME/$1/bin/postactivate ]
        workon "${@:-1}"
        easy_install ipython
        easy_install pysmell
        wget http://www.eletztrick.de/software/mkvimproject/releases/
        easy_install mkvimproject-
        rm mkvimproject-
        touch $WORKON_HOME/$1/bin/postactivate
        echo "cd $WORKON_HOME/$1" >> $postactivate 
        echo "export PYTHONPATH=$WORKON_HOME/$1/scr:$PYTHONPATH" >> $postactivate    
        echo "if [ ! -d $WORKON_HOME/$1/src ]" >> $postactivate
        echo "then" >> $postactivate
        echo "    mkdir -p $WORKON_HOME/$1/src" >> $postactivate
        echo "fi" >> $postactivate
        echo "if [ ! -f $WORKON_HOME/$1/$1.vpj ]" >> $postactivate
        echo "then" >> $postactivate
        echo "    mkvimproject -o $1.vpj -s python" >> $postactivate
        echo "fi" >> $postactivate
        echo "if [ ! -f $WORKON_HOME/$1/PYSMELLTAGS ]" >> $postactivate
        echo "then" >> $postactivate
        echo "    pysmell src;" >> $postactivate
        echo "  cd lib/python2.5;" >> $postactivate;
        echo "  pysmell . -x site-packages -o ../../PYSMELLTAGS.stdlib;" >> $postactivate
        echo "  cd ../..;" >> $postactivate 
        echo "fi" >> $postactivate
        echo "pproject -U" >> $postactivate
    workon "${@:-1}"

then create a new virtual env with mkvirtualenv projectName --no-site-packages
this will setup the environment for vim and allow for the use of pysmell omnicompletion
and allows a ipython shell within the environment.