Skip to content

Unsupported major.minor version 51.0

During deployment of an EAR file on JBoss 6.0 I received this error (the sample is not really what I read on log file)

java.lang.UnsupportedClassVersionError: test_hello_world :
 Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(Unknown Source)

Looking for a solution I’ve found the answer on StackOverflow.

Note to self:

The version number shown describe which version if Java was used to compile the code.

The reported major numbes are:

J2SE 7 = 51,
J2SE 6.0 = 50,
J2SE 5.0 = 49,
JDK 1.4 = 48,
JDK 1.3 = 47,
JDK 1.2 = 46,
JDK 1.1 = 45

(source: )


you have to change the version of java in facet of your project

Halloween Fun with PhoneGap » Andrew Trice

About two weeks ago I had a random thought… “Wouldn’t it be fun to build a free Halloween sound effects app using PhoneGap?” (I tend to get excited for any holiday). I had already done a lot of work using sounds in PhoneGap apps with my LowLatencyAudio native plugin, so the groundwork had already been laid. Next thing you know, I’m searching for sound files ( is a fantastic resource for creative commons sound effects). Write some JS code here, add some CSS styles code there, and next thing you know I had a complete app. The best part – this app went from idea to App Store submission in under 48 hours (yes, I did sleep during this 48 hour period). Add one more day, and it’s ready for Android. That is the power of PhoneGap


see on Andrew Trice » Blog Archive » Halloween Fun with PhoneGap.

A Tcpdump Tutorial and Primer |

tcpdump is the premier network analysis tool for information security professionals. Having a solid grasp of this über-powerful application is mandatory for anyone desiring a thorough understanding of TCP/IP. Many prefer to use higher level analysis tools such as Ethereal Wireshark, but I believe this to usually be a mistake.

In a discipline so dependent on a true understanding of concepts vs. rote learning, it’s important to stay fluent in the underlying mechanics of the TCP/IP suite. A thorough grasp of these protocols allows one to troubleshoot at a level far beyond the average analyst, but mastery of the protocols is only possible through continued exposure to them.

When using a tool that displays network traffic a more natural (raw) way the burden of analysis is placed directly on the human rather than the application. This approach cultivates continued and elevated understanding of the TCP/IP suite, and for this reason I strongly advocate using tcpdump instead of other tools whenever possible.

A Tcpdump Tutorial and Primer |

Create a JBoss AS 7 appliance with VirtualBox – jboss configuration – JBoss application server tutorials

In this tutorial we will demonstrate how to create in a matter of minutes a JBoss AS 7.1.1 appliance designed around a Linux distribution. The software we will use for this purpose is Oracle’s Virtual Box.

When you are done you can turn off your VM. Now we will export our Appliance. What does it mean ? simply that you can create your own Linux VM distribution which already contains a set of applications installed on it (in our case JDK and JBoss AS 7) so that we can reuse it how many times we want it.

Create a JBoss AS 7 appliance with VirtualBox – jboss configuration – JBoss application server tutorials.

Firewall Linux IPCop 2.0, la sicurezza delle reti ha una nuova interfaccia

IPCop Firewall Linux è arrivato alle versione 2.0 con l’aggiornamento al kernel 2.6.32 e con la nuova release è possibile l’installazione flash o hard drive, inoltre è possibile assegnare le schede d’interfaccia a un particolare network; è stato integrato il supporto hardware che include Cobalt e le piattaforme sparc e PPC; ora l’accesso all’interfaccia web è protetto da password e dalla connessione https che è stata cambiata nella 8443.

Un’altro cambiamento è nell’aspetto dell’interfaccia utente che include nuove pagine tra cui quella della pianificazione degli eventi, del menu di sistema, del Proxy e una pagina semplificata per il DHCP server. La lista di tutti i cambiamenti è visibile sul sito ufficiale dove è possibile fare anche il download della nuova versione.

Firewall Linux IPCop 2.0, la sicurezza delle reti ha una nuova interfaccia.