NetBeans project groups

I’m involved on several projects and during my working day it can happen that I need to switch from one project to another.

In NetBeans I usually create a project group for each project, to keep them well separated.

From the Projects window select Project Groups.. menu option. The Manage Groups window allows you to select the project group you want to switch to or to create a new one.

But what is a project group ?

It can be a single project (any NetBeans recognized project types like ant, maven, …). If the project is hierarchical, NetBeans will also include all sub modules in the project group.

It can also be a directory with many different projects. Nice if you like to pack similar projects together (by customer, by type…).

Finally a project group can also be free: every project you will open after the project group creation will be automatically included in it.

If you do nothing, your are in a special None free project group.

Project groups are a nice feature but there is a weak point if we compare NetBeans with the other most popular IDEs: IDEA and Eclipse.

When NetBeans starts, the last used project group is opened again, with consequent project loading and scanning which is annoying if you wanted to work on a different project because you have to wait until complete project loading before switching to the desired project.

On the contrary Idea has a nice startup GUI which shows the list of the past projects in addition to the possibility to create or import a new one. Eclipse has less flexible but still efficient solution based on workspace selection. Both are before loading last opened projects so very fast.

The NetBeans solution is based on the following command line parameters:

  • --open-group NAME
    open a project group by name
  • --close-group
    close any open project group
  • --list-groups
    list available project groups

Invoking NetBeans with --open-group PROJ1 will force NetBeans to immediately close the last opened project group and open the specified one (PROJ1 in this example).

For each project, on Linux and OS-X you can create a dedicated invocation script while on Windows you can create a dedicated icon with a dedicated command line. Tricky but it works.

Another alternative (actually the one I prefer) is to add the `–close-group’ parameter to the netbeans_default_options parameter in the netbeans_home/etc/netbeans.conf file.

The `–close-group’ parameter force NetBeans to switch to the None project group. Once inside NetBeans you can open the project group you like.

For more inside about this feature, have a look at the Enhancement 168556.

NetBeans startup commands are documented here.

Tips: NetBeans on Ubuntu

Ubuntu Linux is a very nice software development platform and NetBeans fit very well in it.

Nevertheless few tips can make our developer life easier. These tips can be applied to other Linux distributions.

1. Do not use apt-get

Apt-get is the Ubuntu/Debian tool to download and install programs from the repositories.

It should not be used to install the tools you need for development, NetBeans included.


  • Repositories contains old versions
  • Dependencies force you to install not needed or incompatible software

Get installation files from the main sources and install them manually in a common dir like /opt.

2. Install NetBeans on a user writable dir

NetBeans needs to update files in its own installation directory during software updates. I suggest to use /opt as the main installation dir.

If /opt is now user writable, execute the following command

sudo chmod 777 /opt

3. Watch the /tmp size

NetBeans use /tmp for temporary operations like, for example, updating Central Maven repository information. While doing this update, NetBeans saves big temporary dirs under /tmp and the update fails if /tmp has no space available.

The /tmp dir is usually small when it is mounted on a dedicated partition.

Reserve at least 1.5GByte free space on the /tmp.

See Bug 162313 for more details.

4. Save NetBeans cache in RAM

NetBeans saves configuration, user preferences and project files status in the NetBeans user dir which is located in $HOME/.netbeans/<version>.

Part of this information, mainly related to projects is considered to be a cache (= it can be recreated if deleted); the cache can be located in a separated dir with the command line –cachedir.

With at least 4 GByte RAM, we can map the cache dir to a temporary RAM on disk using Ubuntu native ram filesystem.

My preferred approach is to

– mount the /tmp to a tmpfs type filesystem, by adding the following line in the /etc/fstab

tmpfs /tmp tmpfs defaults,noatime,nosuid,nodev,noexec,mode=1777,size=2048M 0 0

This will “map” the /tmp dir into RAM up to 2GByte (see tip #3).

– map the cachedir to a /tmp/ subdir, by creating a NetBeans invocation script as the following:

export VERSION=netbeans-8.0.1
export RAMDISK=/tmp/$VERSION
export OPTIONS=" --cachedir $RAMDISK --laf Nimbus "
/opt/$VERSION/bin/netbeans $OPTIONS &

The script will invoke NetBeans with the appropriate options.

Note: I like Nimbus on Ubuntu Unity user interface.

5. Use a SSD drive

SSD drives are an impressive speed improvement. Software development requires reading and writing hundred of files. Speed is essential to have quick feedback during our test and compilations cycles.

The SSD drive can be your main hard drive or an external one (possibly on a fast USB connections). Just place both NetBeans installation dir and your projects files on the SSD unit.

Remember to add noatime option on the mount instructions (see /etc/fstab) to avoid useless write access to the disk.

My 5 favorite NetBeans IDE features (vs. Eclipse)

In my current project, Eclipse Kepler has been selected by the customer as the preferred IDE for all main tasks. Of course, I’m also using NetBeans 8.0 for some activities like, for example, legacy code test coding.

I have already used Eclipse some years ago and, at that time (2009), Eclipse Galileo were quite superior to NetBeans 6.x: faster, rich of code hints and warnings, full of useful plugins. So, I was not really happy when the project moved to NetBeans (because of its Swing support).

Now let me compare them again, Eclipse Kepler 4.3 vs NetBeans 8.0, on same project (a big ant based web project) and on the same PC (Win7 64bit 4G RAM).


My first big surprise. Five years ago, when I moved from Galileo to NetBeans I really missed Eclipse speed: coding, windowing, compilation, everything were significantly faster in Eclipse.

Now this speed advantage is gone. I don’t have benchmarks to demonstrate my feeling but now my coding is visibly faster with NetBeans 8.0 than with Eclipse Kepler. If you install Findbugs and PMD plugins, Eclipse becomes really slow.

Native testing support

Second surprise. Why, in 2014, an IDE for Java EE developers does not include full testing support ?

I cannot imagine any real EE developers which does not need any kind of test support from the IDE.

In NetBeans there is complete native jUnit and TestNG support (templates, test runs, jump to test option in the editor, both *Test and *IT files support) which I found very useful and efficient.

Eclipse native support is poor but of course it can be extended via plugin. I’m using MoreUnit plugin which is quite nice and add many missing features to Eclipse. See here for a small tutorial.

But even if you install a test support plugin like MoreUnit, still an important Eclipse limitation remains : the possibility to have a dir for test files separated from the main src dir, which is an essential feature to let us handling deployments. If you don’t believe me, have a look at this 2008 bug still open: and its related bugs.
Simply unbelievable.

Java Hints and FindBugs integration

While coding, it is important to have feedbacks from the IDE about the quality of the code and possible errors. NetBeans Java hints is a very reach set of the code checks which helps me to avoid stupid errors and keep high the quality of my work. In addition, NetBeans includes first class support for FindBugs which, again, helps me during coding sessions.

I’ve found NetBeans code quality checks support better than the one available in Eclipse Kepler + FindBugs plugin. More checks and better control on how, for example, disable a FindBugs warning on a line (because it is ok) using an annotation: just a click with NetBeans and by hand with Eclipse.

Coding support: templating, completion,interfaces…

I like NetBeans coding support: code templates (some letters + tab to get most used keywords and structures (see here for some examples), auto-completion, now also using sub words, I can easily jump from an interface to its implementation, the new indent guide lines.

Similar features are available in Eclipse using, for example, the Code Recommenders plugin but I’ve found it quite slow on my machine so I had to disinstall it.

User Interface

NetBeans user interfaces has improved a lot while keeping its strong point: it is easy to use. Windows and menus are easy to find and the full screen mode is very useful on small screens. I really like the color coding setup (Norway Today) which makes code reading a pleasure and the dark skins for working late in the evening.

On the contrary, Eclipse interfaces remains somehow confusing and, my personal opinio, perspectives and workspaces are simply a waste of time.

Tutorial: how to create a JUnit test method template in NetBeans

NetBeans has a very nice feature: code templates.

Let me show how I use it to add a new JUnit test method in the test classes.

Go to Tools → Options → Editor → Code Templates and add the following template:

Abbreviation: te (this is only my proposal)

Expanded text:

@${baseType type="org.junit.Test" default="Test" editable="false"}
public void ${cursor}() {
    // given

    // when

    // then


2014-03-05_pic01Then go to a test class, type “te” (our template abbreviation) and press the TAB key.

See what’s happen:


First, the org.junit.Test include has been added (if not already in). This is thanks to the ${baseType} instruction we added in the template.

Second, the prompt is waiting for you for the method name. See ${cursor} instruction in the template.

Just write the name and we have complete test method template in our class.


Of course, the template can be adjusted to your needs and habits.


  • we code faster
  • we have more uniform code style

NetBeans code template syntax is (partially) documented here.

Tutorial: license headers in NetBeans (reloaded)

An alternative solution to the native NetBeans license header management (see my previous post) is the “License Changer” plugin by nhoffmann available on NetBeans plugin portal (

The plugin is based on license template concept. NetBeans installation includes several license templates (Tools → Templates) for the most popular Open Source licenses: 2014-02-25_pic01The plugin uses one of the available templates. If you have your own license file, you have to include it in the template list (but the plugin help on this).

NOTE: all custom license files will be saved in the NetBeans User Directory. You can have a look at the beginning of View → IDE Log for your real path.

With the plugin we can do more that native NetBeans solution except for one use-case: when you have a proprietary and project specific license. In this case NetBeans let us save the license file within the project (so all team members can use it) while, with the plugin, all licenses are stored in the user NetBeans installation (which is not shared across the team).

Let’s describe now the plugin.

After plugin installation, you can select a file or a package and apply “Change License Header” (see picture below).

2014-02-25_pic02A wizard starts. On the first page we can select the files types on which the plugin should operate on (see 1). Nice added feature is the possibility to change the line endings character (see 2).



Second page of the wizard is the following:


We can select the license from the template list (see 1) or browse the disk for a custom license file (see 2) which will be included in the template list by the plugin.

IMPORTANT: The checkbox “Set as default project license” (see 3) is very important. If checked, the plugin will save the selected license in the project configuration (the same used by native NetBeans solution). All new created files (including file types not supported by the plugin) will inherit the setting and they will have the correct license header.

After license selection:

2014-02-25_pic05The rest of the wizard is very simple.

NOTE: One little annoying problem with the plugin is that the selected license is not kept for the following plugin invocations.

Typical procedure :

  1. install the plugin
  2. run the plugin on a project file or package or folder,in order to include all existing project files
  3. use standard NetBeans File → New File procedure to create new project files

Tutorial: license headers in NetBeans

NetBeans has special support for the license headers we usually add at the begin of the source files for copyright messages and references to license agreement.

In the project properties we can find a dedicated section to license headers:

2014-02-18_pic01The “Use Global license” options let us choose among popular license header: Apache, GPL, MIT, NetBeans but in this tutorial we will create a custom license header.

First step is to create a file for our project license header. Let’s create a text file on the root of the project which will contain the text of the license header.



In this example, the file is named mylicense.txt and it is placed in the root of the project.

Now we open the mylicense.txt file to add some contents.


The text is free but it should formatted as a comment (in my case I used the Java block comment: /* */ ).

Important: actually the syntax of the license file can be more complex than in our example because it is processed by a tool during the inclusion process. I will post a new tutorial on this topic.

Save the file and close the editor window.

Now we return to the project properties window to specify the path of our project specific license header:


I used the variable ${project.basedir} which is the symbolic path to the project root dir. The window shows the preview of the license header.

Now, when we create a new file (in the example a new Java Class file), we have our template header in place:


For the moment, there is no option in NetBeans to add the template header to an already existing file but I filled an enhancement request on this.