NetBeans (@ http://netbeans.org) is an open-source Integrated Development Environment (IDE). NetBeans began in 1996 as a Java IDE student project at Charles University in Prague. Sun Microsystems acquired NetBeans in 1999. In 2010, Oracle acquired Sun (and thus NetBeans).

Compared with its rival Eclipse (http://www.elicpse.org) (both are open-source, so I don't know what are they competing for?), NetBeans provides seamless support for Java AWT/Swing, Java ME mobility pack, Java EE, and bundled with an excellent profiler for performance tuning.

NOTE (2018 Feb 01): NetBeans 8.2 might not work with JDK 9 at this moment. Stick to JDK 8 now, if you want to use NetBeans.

I assumed that you have already installed the JDK (Java Development Kit) version 11.0.4 LTS.C: Program Files Java jdk-11.0.4.Open JDK 11 is available from he. Apache NetBeans 12 LTS (NB 12.0) Latest LTS version of the IDE, released on June 4, 2020. Features Download. You must have installed Apache NetBeans 11.0 by downloading a zip file named incubating-netbeans-11.0-bin.zip, then unzipping it to an installation directory, because that is the only approach that is offered. From the Apache NetBeans web site: Apache NetBeans 11.0 is available for download from your closest Apache mirror.

How to Install NetBeans 8.2

How to Install NetBeans on Windows

Step 0: Install JDK

To use NetBeans for Java programming, you need to first install Java Development Kit (JDK). See 'JDK - How to Install'.

Step 1: Download

Download 'NetBeans IDE' installer from http://netbeans.org/downloads/index.html. There are many 'bundles' available. For beginners, choose the 1st entry 'Java SE' (e.g., 'netbeans-8.2-javase-windows.exe' 95MB).

Step 2: Run the Installer

Run the downloaded installer.

How to Install NetBeans on Mac OS X

To use NetBeans for Java programming, you need to first install JDK. Read 'How to install JDK on Mac'.

To install NetBeans:

Download NetBeans from http://netbeans.org/downloads/. Set 'Platform' to 'Mac OS X'. There are many 'bundles' available. For beginners, choose 'Java SE' (e.g., 'netbeans-8.2-javase-macosx.dmg' 116MB).
Double-click the download Disk Image (DMG) file.
Double-click the 'NetBeans 8.x.mpkg', and follow the instructions to install NetBeans. NetBeans will be installed under '/Applications/NetBeans'.
Eject the Disk Image ('.dmg').

You can launch NetBeans from the 'Applications'.

Notes: To uninstall NetBeans, drag the '/Applications/NetBeans' folder to trash.

How to Install NetBeans on Ubuntu Linux

To use NetBeans for Java programming, you need to first install JDK. Read 'How to install JDK on Ubuntu'.

To install NetBeans:

Download NetBeans from http://netbeans.org/downloads/. Choose platform 'Linux (x86/x64)' ⇒ 'Java SE'. You shall receive a sh file (e.g., 'netbeans-7.x-ml-javase-linux.sh') in '~/Downloads'.
Set the downloaded sh file to executable and run the sh file. Open a Terminal: Follow the instructions to install NetBeans.

To start NetBeans, run the script 'netbeans' in the NetBeans' bin directory:

Writing a Hello-world Java Program in NetBeans

Step 0: Launch NetBeans

Launch NetBeans. If the 'Start Page' appears, close it by clicking the 'cross' button next to the 'Start Page' title.

Step 1: Create a New Project

For each Java application, you need to create a 'project' to keep all the source files, classes and relevant resources.

From 'File' menu ⇒ Choose 'New Project...'.
The 'Choose Project' diglog pops up ⇒ Under 'Categories', choose 'Java' ⇒ Under 'Projects', choose 'Java Application' ⇒ 'Next'.
The 'Name and Location' dialog pops up ⇒ Under 'Project Name', enter 'FirstProject' ⇒ In 'Project Location', select a suitable directory to save your works ⇒ Uncheck 'Use Dedicated Folder for Storing Libraries' ⇒ Uncheck 'Create Main class' ⇒ Finish.

Step 2: Write a Hello-world Java Program

Right-click on 'FirstProject' ⇒ New ⇒ Java Class (OR choose the 'File' menu ⇒ 'New File...' ⇒ Categories: 'Java', File Types: 'Java Class' ⇒ 'Next').
The 'Name and Location' dialog pops up ⇒ In 'Class Name', enter 'Hello' ⇒ Delete the content in 'Package' if it is not empty ⇒ 'Finish'.
The source file 'Hello.java' appears in the editor panel. Enter the following codes:

Step 3: Compile & Execute

There is no need to 'compile' the source code in NetBeans explicitly, as NetBeans performs the so-called incremental compilation (i.e., the source statement is compiled as and when it is entered).

To run the program, right-click anywhere in the source (or from the 'Run' menu) ⇒ Run File. Observe the output on the output console.

Notes:

You should create a NEW Java project for EACH of your Java application.
Nonetheless, NetBeans allows you to keep more than one programs in a project, which is handy for writing toy programs (such as your tutorial exercises). To run a particular program, open and right-click on the source file ⇒ Run File.

Correcting Syntax Error

NetBeans performs incremented compilation, as and when a source line is entered. It marked a source line with syntax error with a RED CROSS. Point your cursor at the RED CROSS to view the error message.

You CANNOT RUN the program if there is any syntax error (marked by a RED CROSS before the filename). Correct all the syntax errors; and RUN the program.

[TODO] Diagram

HINTS: In some cases, NetBeans shows a ORANGE LIGHT-BULB (for HINTS) next to the ERROR RED-CROSS (Line 5 in the above diagram). You can click on the LIGHT-BULB to get a list of HINTS to resolve this particular error, which may or may not work!

SYNTAX WARNING: marked by a orange triangular exclaimation sign. Unlike errors, warnings may or may not cause problems. Try to fix these warnings as well. But you can RUN your program with warnings.

Read the NetBeans Documentation

At a minimum, you SHOULD READ the 'IDE Basics, Getting Started, Java Application', which is accessible via NetBeans's 'HELP' menu ⇒ Help Contents. This will save you many agonizing hours trying to figure out how to do somethings later.

The 'Help' ⇒ 'Online Doc and Support' (@ http://netbeans.org/kb/index.html) contains many articles and tutorial on using NetBeans.

The NetBeans 'Start Page' also provides many useful links to get you started.

Debugging Program in NetBeans

Step 0: Write a Java Program

The following program computes and prints the factorial of n (=1*2*3*...*n). The program, however, has a logical error and produce a wrong answer for n=20 ('The Factorial of 20 is -2102132736' - a negative number?!).

Let us use the graphic debugger to debug the program.

Step 1: Set an initial Breakpoint

A breakpoint suspends program execution for you to examine the internal states of the program. Before starting the debugger, you need to set at least one breakpoint to suspend the execution inside the program. Set a breakpoint at main() method by clicking on the left-margin of the line containing main(). A red circle or an inverted Triangle appears in the left-margin indicating a breakpoint is set at that line.

Step 2: Start Debugging

Right click anywhere on the source code ⇒ 'Debug File'. The program begins execution but suspends its operation at the breakpoint, i.e., the main() method.

As illustrated in the following diagram, the highlighted line (also pointed to by a green arrow) indicates the statement to be executed in the next step.

Step 3: Step-Over and Watch the Variables and Outputs

Click the 'Step Over' button (or select 'Step Over' in 'Debug' menu) to single-step thru your program. At each of the step, examine the value of the variables (in the 'Variable' panel) and the outputs produced by your program (in the 'Output' Panel), if any. You can also place your cursor at any variable to inspect the content of the variable.

Single-stepping thru the program and wa

How To Install Apache Netbeans 11.0 On Windows