Roman Uhlig: DevBlog

Favicon with Wicket and HeaderContributer

2009-09-17T17:46:00.002+02:00

Based on Michael's example, I did a complete example for a Wicket header contributer generating a favicon entry:

public class FavIconHeaderContributor extends AbstractHeaderContributor {
 
 private static final long serialVersionUID = 1L;

 private final FavIconContributor contributor;
 
 private static final class FavIconContributor implements IHeaderContributor {
 
  private static final long serialVersionUID = 1L;
  
  ResourceReference _resourceReference;
 
  public FavIconContributor(ResourceReference resourceReference) {
   _resourceReference = resourceReference;
  }
 
  public void renderHead(IHeaderResponse response) {
   CharSequence url = RequestCycle.get().urlFor(_resourceReference);
   response.renderString(getFavIconReference(url));
  }
 
  private CharSequence getFavIconReference(CharSequence url) {
   StringBuilder sb = new StringBuilder();
   sb.append("<link rel=\"shortcut icon\" href=\"");
   sb.append(url);
   sb.append("\" type=\"image/x-icon\">\n");
   return sb.toString();
  }
  
 }
 
 public FavIconHeaderContributor(ResourceReference resourceReference) {
  contributor = new FavIconContributor(resourceReference);
 }

 @Override
 public final IHeaderContributor[] getHeaderContributors() {
  return new IHeaderContributor[] { contributor };
 }

 @Override
 public String toString() {
  return contributor._resourceReference.getName();
 }
 
}

Some PostgreSQL stuff

2009-05-06T18:53:00.005+02:00

Just some bits that might be useful when working with PostgreSQL databases. Everything is working with version 8.x, I can't say anything about the compatibility with older versions.

Display the sizes all of your databases running on a particular server:

SELECT pg_database.datname, pg_size_pretty(pg_database_size(pg_database.datname)) AS size FROM pg_database;

Show running PostgreSQL thread on Linux:

ps auxww | grep ^postgres

When upgrading to a new version (usually major or secondary), you have to do a full dump and restore. This one works well for me for some time now:

    * pg_dumpall -o -U postgres > [dump file]
    * stop postgresql server
    * you may want to save your configuration files (e.g. postgresql.conf, pg_hba.conf)
    * now you may safely remove your old postgresql installation
    * rm -rf /var/lib/postgresql/data
    * install new postgresql
    * merge changes from postgresql.conf and pg_hba.conf
    * start new postgresql server
    * psql -f [dumpfile] -U postgres

script based phpBB user add

2009-04-27T16:38:00.004+02:00

For a customer I had to implement a script based user management for phpBB (add/delete) called from within a Java web app using existing login data. After evaluating and merging a lot of non-working suggestions/examples I managed to build a working script (tested with phpBB 3.0.4). Maybe it saves you some time.


<?php
if (isset($_REQUEST['forum_username']) && isset($_REQUEST['forum_password']) && isset($_REQUEST['forum_email'])) {
 
 define('IN_PHPBB', true);
 
 $phpbb_root_path = (defined('PHPBB_ROOT_PATH')) ? PHPBB_ROOT_PATH : '../forum/';     
 $phpEx = substr(strrchr(__FILE__, '.'), 1);

 include($phpbb_root_path . 'common.' . $phpEx);
 include($phpbb_root_path . 'includes/ucp/ucp_register.php');
 include($phpbb_root_path . 'includes/functions_user.' . $phpEx);
 
 $username = $_REQUEST['forum_username'];
 $username_clean = strtolower($username_clean);
 $password = $_REQUEST['forum_password'];
 $email = $_REQUEST['forum_email'];
 
 $user_row = array(
  'username' => $username,
  'username_clean' => $username_clean,
  'user_password' => phpbb_hash($password),
  'user_pass_convert' => 0,
  'user_email' => $email,
  'user_email_hash' => crc32(strtolower($email)) . strlen($email),
  'group_id' => 7,
  'user_type' => 0,
 );
 
 user_add($user_row);
}
?>

Wicket base webapp

2009-04-13T17:56:00.014+02:00

After having some trouble finding a slim and small base layout in the web, serving as template for any Wicket application I might develop (without using Jetty or providing any "quickstart" framework), I'd like to post a solution using filters instead of the Wicket servlet (recommended as of Wicket 1.4+):

web.xml:


<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
      PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
      "http://java.sun.com/dtd/web-app_2_3.dtd">

<web-app>
  <display-name>Wicket Base</display-name>

  <context-param>
    <param-name>configuration</param-name>
    <param-value>deployment</param-value>
  </context-param>
 
  <filter>
    <filter-name>wicketbase</filter-name>
    <filter-class>org.apache.wicket.protocol.http.WicketFilter</filter-class>
    <init-param>
      <param-name>applicationClassName</param-name>
      <param-value>com.wicketbase.WebApplicationBase</param-value>
    </init-param>
  </filter>

  <filter-mapping>
    <filter-name>wicketbase</filter-name>
    <url-pattern>/wbase/*</url-pattern>
  </filter-mapping>
   
</web-app>

WebApplicationBase.java:


public class WebApplicationBase extends WebApplication {

  @Override
  protected void init() {
    this.getMarkupSettings().setDefaultMarkupEncoding("UTF-8");
    this.getRequestCycleSettings().setResponseRequestEncoding("UTF-8");
  }

  @Override
  public Class getHomePage() {
    return WebPageBase.class;
  }

  public static WebadminApplication get() {
    return (WebadminApplication) Application.get();
  }

  @Override
  public Session newSession(Request request, Response response) {
    return new WebSessionBase(request);
  }

}

WebSessionBase.java:


public class WebSessionBase extends WebSession {

  public static WebSessionBase get() {
    return (WebSessionBase) Session.get();
  }

  protected WebSessionBase(Request request) {
    super(request);
    setLocale(new Locale("de", "DE_EURO"));
  }


}

WebPageBase.java:


public class WebPageBase extends WebPage {
 
  public WebPageBase() {
    add(HeaderContributor.forCss(WebadminPage.class, "res/style.css"));
  }

  public WebSessionBase getWebSessionBase() {
    return (WebSessionBase)getSession();
  }
}

WebPageBase.html (just for completing this example):


<?xml version="1.0" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:wicket="http://wicket.apache.org/" xml:lang="en" lang="en">
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>

<body>
...
</body>
</html>

Ant build script:


<?xml version="1.0" encoding="UTF-8"?>
<project default="war" name="wicketbase" basedir=".">
 <property name="final.name" value="wicketbase" />
 <property name="src.main.dir" value="src/com/wicketbase" />
 <property name="src.web.dir" value="webapp" />
 <property name="lib.dir" value="lib" />
 <property name="build.dir" value="target" />
 <property name="build.main.classes" value="bin" />
 <property name="build.reports.dir" value="${build.dir}/reports" />
 <path id="build.classpath">
  <fileset dir="${lib.dir}">
   <include name="**/*.jar" />
  </fileset>
 </path>
 <target name="clean">
  <delete dir="${build.dir}" failonerror="false" />
  <delete file="${final.name}.war" failonerror="false" />
 </target>
 <target name="init">
  <mkdir dir="${build.dir}" />
 </target>
 <target name="compile" depends="init">
  <mkdir dir="${build.main.classes}" />
  <javac destdir="${build.main.classes}" target="1.5" source="1.5"
   srcdir="${src.main.dir}" classpathref="build.classpath" />
  <copy todir="${build.main.classes}">
   <fileset dir="${src.main.dir}">
    <include name="**/*.*" />
    <exclude name="**/*.java" />
   </fileset>
  </copy>
 </target>
 <target name="war" depends="compile">
  <war destfile="${build.dir}/${final.name}.war" webxml="${src.web.dir}/WEB-INF/web.xml">
   <lib dir="lib">
    <include name="*.jar" />
   </lib>
   <classes dir="${build.main.classes}" />
   <fileset dir="${src.web.dir}">
    <include name="**/*" />
    <exclude name="**/web.xml" />
   </fileset>
  </war>
 </target>
</project>

The folder layout of the webapp is as you would probably expect it. Wicket jar's go to "WEB-INF/lib", your classes and the HTML go to "WEB-INF/classes/[package]".

Regular expression for email validation

2009-03-04T12:40:00.007+01:00

After unsuccessfully searching the web for a working common POSIX conform regular expression for validating email addresses, I took the time and built one. It should cover almost almost any possible format: