When you need to debug Java code for Alfresco projects using IntelliJ, it's common to face with the exceptionnet.sf.acegisecurity.providers.ProviderNotFoundException: No authentication provider for net.sf.acegisecurity.providers.UsernamePasswordAuthenticationTokenA quick settings change on IntelliJ can fix that:Go to File -> SettingsIn the Settings window's treeview, browse to Build, Execution, Deployment -> Debugger -> Data Views -> JavaUncheck "Enable 'toString()' object view:"Click ok and try again.That change works for me. If you need to connect to an Oracle database, you can use Oracle SQL Developer.To do so, you need to download the installer from Oracle's website here http://www.oracle.com/technetwork/developer-tools/sql-developer/downloads/index.htmlBefore you are able to download it, you will have to login or create an Oracle account here https://login.oracle.com/mysso/signon.jspThe version I'm going to use is 4.0.3 (4.0.3.16.84), from September 15, 2014.Download the rpm one.Once the download is finished, using terminal, go to the folder where you saved the installer and execute:Install the required dependencies: sudo apt-get install alien lsbYou will also need a JDK (Java Development Kit) installed. If you don't have it, follow this tutorial http://douglascrp.blogspot.com/2014/08/how-to-install-oracle-java-on-ubuntu.htmlWith dependencies in place, execute:sudo alien --scripts sqldeveloper*rpmand thensudo dpkg -i sqldeveloper*debIf everything is ok, you are ready to start Oracle SQL Developer.Using terminal, execute:sqldeveloperOn the first time you run it, it wil ask you to provide a valid JDK installation path.Type the full pathname of a JDK installation (or Ctrl-C to quit), the path will be stored in /home/user/.sqldeveloper/4.0.0/product.conf If you followed the tutorial above, type:/usr/lib/jvm/java-7-oracleHit enter and it's done. Sometimes, when you try perform some activities on Ubuntu like manage packages using apt-get, you can see messages like:perl: warning: Setting locale failed.perl: warning: Please check that your locale settings:LANGUAGE = "en_US:en",LC_ALL = (unset),LC_TIME = "pt_BR.UTF-8",LC_MONETARY = "pt_BR.UTF-8",LC_ADDRESS = "pt_BR.UTF-8",LC_TELEPHONE = "pt_BR.UTF-8",LC_NAME = "pt_BR.UTF-8",LC_MEASUREMENT = "pt_BR.UTF-8",LC_IDENTIFICATION = "pt_BR.UTF-8",LC_NUMERIC = "pt_BR.UTF-8",LC_PAPER = "pt_BR.UTF-8",LANG = "en_US.UTF-8"are supported and installed on your system.perl: warning: Falling back to the standard locale ("C").andlocale: Cannot set LC_ALL to default locale: No such file or directoryYou can see what the problem is by typing:localeYou will see something like:locale: Cannot set LC_ALL to default locale: No such file or directoryLANG=en_US.UTF-8LANGUAGE=en_US:enLC_CTYPE="en_US.UTF-8"LC_NUMERIC=pt_BR.UTF-8LC_TIME=pt_BR.UTF-8LC_COLLATE="en_US.UTF-8"LC_MONETARY=pt_BR.UTF-8LC_MESSAGES="en_US.UTF-8"LC_PAPER=pt_BR.UTF-8LC_NAME=pt_BR.UTF-8LC_ADDRESS=pt_BR.UTF-8LC_TELEPHONE=pt_BR.UTF-8LC_MEASUREMENT=pt_BR.UTF-8LC_IDENTIFICATION=pt_BR.UTF-8LC_ALL= As you can see, LC_ALL has no value.Type:sudo locale-gen pt_BR.UTF-8sudo update-localeReboot your server and check again by typing:localeIf you see no errors, it's fixed.See ya. I don't know about you, but I've faced with a common problem when getting someone else's work to finish on Java.It's about getting the Java source code of projects.Sometimes, the only thing you get is the jar file containing the compiled Java classes. When it comes to problems like this, it's always useful to have some tools ready to be used, and I got to know an awesome Java decompiler on this tweet https://twitter.com/samuel_langlois/status/532957813019275264It can be used as an stand alone application, or as an Eclipse or IntelliJ plugin.Everything you need to get, install and use it is at this page http://jd.benow.ca/UPDATE:When I tried to execute the stand alone application on Ubuntu 14.04 64 bit, I got this error message:./jd-gui: error while loading shared libraries: libgtk-x11-2.0.so.0: cannot open shared object file: No such file or directoryIn order to fix it, simply install the 32 bits version of