The new Ubuntu release 11.04 Natty contains the new Unity desktop environment which is quite controversal. I have tried it for a while and I think it is neat but too buggy and immature. However, it is easy to revert to the old Gnome 2 desktop environment and have things working almost as in 10.10. First do a normal distribution upgrade to 11.04, then go to System Settings -> Login Screen and select Ubuntu Classic as default session and reboot.

I just brought an Sveon SNT1020 WiFi USB adapter. It works very well with Ubuntu Linux 10.10, just connect it to an USB 2 port and you can start using it with NetworkManager right away, no drivers or setup necessary. You should possibly disable any built-in WiFi adapters first though. It cost €35.

When you know which type of web application you are to develop, it’s time to have a look at some possible choices. I have tried to categorize some modern and popular web application frameworks in Java. Simple server driven MVC page based This category contains the traditional frameworks used for developing web applications with purely server driven application logic. They are based on complete HTML pages and uses the Model-View-Controller design pattern.

If you are to develop a web application, there are a lot if frameworks to choose between. I assume that the web application by its nature needs to have bi-directional communication between the web browser and the server during the execution, initial downloading of resources is not enough. I also assume that the available technologies are HTML, CSS and JavaScript/AJAX; no Flash, Java applets, ActiveX, Silverlight or other browser plug-ins are used.

If you have your home directory on another machine, it’s common to use NFS to access it. NFS is easy to set up and works more or less out of the box on Linux. However, NFS is not secure, and you need to have a carefully setup firewall in order to use it safely. SSHFS is a more secure alternative, but it’s quite tricky to set up on the client side.

Vaadin is a comprehensive framework for developing web applications in Java. The Vaadin web site presents a number of ways to use Vaadin with Maven, but I am not completely satisfied with any of those. Here is how I do it. Use a pom.xml like this: <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.thecompany</groupId> <artifactId>theapp</artifactId> <version>1.0</version> <packaging>war</packaging> <name>The App</name> <dependencies> <dependency> <groupId>com.vaadin</groupId> <artifactId>vaadin</artifactId> <version>6.3.3</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.

Spring Web Services together with JAXB 2.0 provides a convenient way to implement POX Web Services in Java. POX means Plain Old XML, and a POX Web Service is a protocol based on sending XML over HTTP without using any well-known protocol framework like SOAP or XML-RPC. First you have to define annotated JAXB classes for all XML request and response messages. If you have a schema, you can generate them with the xjc tool.

You can implement RESTful Web Services in Java using the JAX-RS framework. JAX-RS is part of the JavaEE 6 platform. But if you are not using a JavaEE 6 application server, you can use the reference implementation Jersey and embed it in any web application server. However, it’s quite awkward to produce JSON output from Jersey. Jersey has some support for producing JSON via JAXB, but to get the NATURAL encoding (which you probably want) you need JAXB 2.

(This is a new version of a previous post updated to work with Ubuntu 9.10 (karmic).) I wondered why you usually mount / (the root file system) read-write in Linux and decided to do some experiments to find out if it is possible to have it mounted read-only. So why do you want to do that? Perhaps you have the root file system on a read-only media, such as CD-ROM. Or on a writable media which can only handle a limited number of writes, such as a CD-RW or flash disk.

I finally got the microphone input on my Acer Veriton X270 to work un Ubuntu 9.04. The trick is to uninstall PulseAudio and use ALSA only. It even works in Skype.