naeyesi lennen jaerel
Emigdio Binet
It's time to write your first application! These detailed instructions are for users of the NetBeans IDE. The NetBeans IDE runs on the Java platform, which means that you can use it with any operating system for which there is a JDK available. These operating systems include Microsoft Windows, Solaris OS, Linux, and Mac OS X.
When you create an IDE project, you create an environment in which to build and run your applications. Using IDE projects eliminates configuration issues normally associated with developing on the command line. You can build or run your application by choosing a single menu item within the IDE.
A source file contains code, written in the Java programming language, that you and other programmers can understand. As part of creating an IDE project, a skeleton source file will be automatically generated. You will then modify the source file to add the "Hello World!" message.
The IDE invokes the Java programming language compiler (javac), which takes your source file and translates its text into instructions that the Java virtual machine can understand. The instructions contained within this file are known as bytecodes.
To set this JDK as the default for all projects, you can run the IDE with the --jdkhome switch on the command line, or by entering the path to the JDK in the netbeans_j2sdkhome property of your INSTALLATION_DIRECTORY/etc/netbeans.conf file.
When you created this project, you left the Create Main Class checkcbox selected in the New Project wizard. The IDE has therefore created a skeleton class for you. You can add the "Hello World!" message to the skeleton code by replacing the line:
If the build output concludes with the statement BUILD FAILED, you probably have a syntax error in your code. Errors are reported in the Output window as hyperlinked text. You double-click such a hyperlink to navigate to the source of an error. You can then fix the error and once again choose Run Build Project.
When you build the project, the bytecode file HelloWorldApp.class is generated. You can see where the new file is generated by opening the Files window and expanding the Hello World App/build/classes/helloworldapp node as shown in the following figure.
The next few pages of the tutorial will explain the code in this simple application. After that, the lessons go deeper into core language features and provide many more examples. Although the rest of the tutorial does not give specific instructions about using the NetBeans IDE, you can easily use the IDE to write and run the sample code. The following are some tips on using the IDE and explanations of some IDE behavior that you are likely to see:
Once you have created a project in the IDE, you can add files to the project using the New File wizard. Choose File New File, and then select a template in the wizard, such as the Empty Java File template.
You can compile and run an individual file (as opposed to a whole project) using the IDE's Compile File (F9) and Run File (Shift-F6) commands. If you use the Run Main Project command, the IDE will run the file that the IDE associates as the main class of the main project. Therefore, if you create an additional class in your HelloWorldApp project and then try to run that file with the Run Main Project command, the IDE will run the HelloWorldApp file instead.
As you are typing in the IDE, a code completion box might periodically appear. You can either ignore the code completion box and keep typing, or you can select one of the suggested expressions. If you would prefer not to have the code completion box automatically appear, you can turn off the feature. Choose Tools Options Editor, click the Code Completion tab and clear the Auto Popup Completion Window check box.
If you want to rename the node for a source file in the Projects window, choose Refactor from IDE's main menu. The IDE prompts you with the Rename dialog box to lead you through the options of renaming the class and the updating of code that refers to that class. Make the changes and click Refactor to apply the changes. This sequence of clicks might seem unnecessary if you have just a single class in your project, but it is very useful when your changes affect other parts of your code in larger projects.
NetBeans has a nifty little plugin capability allowing you to extend the software with your own plugins. In general you can use the plugin manager to install and remove these, and it works well (even restarting NetBeans for you).
Unlike Eclipse, which generally puts all its plugins in a single plugin directory inside Eclipse (called plugins), NetBeans separates out its plugin modules from the main installation. The core modules are kept separate from your own additions (which makes things much tidier). They are actually stored in a location called .netbeans on my Linux or Windows setup (which lives inside your user directory (something like /home/me/ on Linux and C:/Documents and Settings/me on Windows).
On the Mac they are stored in a separate location Library/Application Support/netbeans. Helpfully the Mac finder hides the Library directory so you may need to create a symbolic link or the command line to access them.
Inside this directory you will find several NetBeans sub-directories (7.2, 7.3, etc) and inside that you will find the plugins (there is also an xml file in update_tracking). Here is a screenshot from my Mac showing this.
On Mac OS X, this file is hidden due to the way Mac OS X packages are deployed. To view and edit the netbeans.conf file on OS X, right-click on the NetBeans.app executable file and select the Show Package Contents menu option:
This configuration is a simple text file and can be opened with any text editor. In the file, we can see several configuration properties that can be modified to suit your requirements. Let's go through these now and see what options are available.
Earlier in this chapter, we discussed the NetBeans user and cache directories and what information is stored within them. If you wish to change the user directory for a specific instance of NetBeans (for example, you may want to use a completely fresh user directory or a user directory from a previous installation of NetBeans), this can be achieved by specifying the netbeans_default_userdir parameter. Similarly, the cache directory can be changed by specifying the netbeans_default_cachedir parameter:
The NetBeans default startup options are probably the most likely of the command-line arguments that you'll need to change for NetBeans. These options are specified by the netbeans_default_options parameter:
The first option (-J-client) specifies that the JVM for NetBeans will run as a client VM instead of server VM. The client VM is essentially useful for applications requiring fast startup or small footprints. The server VM is typically used where performance is more important.
The final parameters specified in the default options ensure that certain optimizations are performed on the JVM to make it more stable and perform better. Some of these parameters are operating system-specific and may not exist on configuration files for different operating system.
By default, NetBeans uses the system-defined JDK to run the IDE (you'll remember this can be overridden using the --javahome argument to the NetBeans installer, as discussed earlier in this chapter). This can be overridden in the netbeans.conf file by defining the netbeans_jdkhome property to specify the base directory of a different JDK installation:
It's not usually necessary to change the JDK that NetBeans uses as this is set at the time of installation. However, if you wish to use a newer (or older) JDK than the one used when you installed NetBeans, it can be configured with this variable.
A NetBeans cluster is a directory on disk that contains a set of modules such as the NetBeans Platform or the Java EE support within the NetBeans IDE. Additional clusters can be configured within NetBeans by adding the directory in which the cluster resides onto the netbeans_extraclusters parameter:
It is most likely that you will not need to define the additional module clusters to be loaded at the startup unless you are developing NetBeans rich client platform (RCP) applications.
If you wish to increase the base font size of NetBeans, the --fontsize option allows this to be achieved. For example, --fontsize 20 increases the base font size to 20px. This can be useful when demoing code or showing NetBeans to larger audiences.
Start errormessage
org.netbeans.InvalidException: StandardModule:org.sleuthkit.autopsy.core jarFile: /Users/petersopka/autopsy/autopsy-4.19.2/autopsy/modules/org-sleuthkit-autopsy-core.jar: java.lang.UnsupportedClassVersionError: org/sleuthkit/datamodel/SleuthkitJNI has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0
End errormessage