Java programming. There are a number of IDEs present, all of them are fine but perhaps some are easier to work with than others. It depends on the users level of programming and tastes! The following is a list of some of the IDEs available: BlueJ – www.bluej.org (freeware) NetBeans – www.netbeans.org (freeware/open-source). Windows 7 Windows 8 Windows 10 Mac OS X Language: EN Version: 5.15. C programming software for mac; Download c for mac - Best answers; C for mac - Best answers; How to Remove Startup Programs on a Mac - How-To - MacOS; Free video conversion software for Mac OS X. Download Java Programming for Windows 10 for Windows to this Java Programming app enables you to carry Java programming Tutorials in your device.
This document instructs you on how to set up a Java programming environment for your Mac OS X computer. It also provides a step-by-step guide for creatingand compiling a Java program in IntelliJ and executing itfrom the command line.
You will need a Mac runningMac OS X 10.13 (High Sierra) to Mac OS X 10.15 (Catalina).
Java Programming Language Download For Mac Os
0. Install the Java Programming Environment |
The installer installs and configures a Java programming environment, includingOpenJDK 11 andIntelliJ IDEA, Community Edition 2020.1.
- Log in to the user account in which you will be programming.Your account must have Administrator privileges.
- Download the Mac OS X installerlift-java.pkg.
- Double-click lift-java.pkg to install the software.Enter your Mac OS X password when prompted and use all of the default options.WarningIf you have previously used IntelliJ,run this installer only if you want a clean re-install.The installer overwrites IntelliJ IDEA CE.app andany previous IntelliJ 2020.1 settings.
- Delete lift-java.pkg (if it is not automatically deleted).
1. Open a Project in IntelliJ |
You will develop your Java programs in an application called IntelliJ IDEA, Community Edition.
IntelliJ organizes Java programs into projects.In our context, each project corresponds to one programming assignment.A typical project contains Java programs, associated data files, andcourse-specific settings (such as compiler options, style rules, and textbook libraries).
- Download the project for your programming assignment to a convenient location(such as the Desktop).[ sample project for COS 126 (Princeton) ][ sample project for COS 226 (Princeton) ][ sample project for Computer Science: Programming with a Purpose (Coursera) ][ sample project for Algorithms, Part I (Coursera) ]Double click the zip file to unzip.This creates a project folder with thename of the corresponding programming assignment (such as
hello
orpercolation
).Delete the zip file.WarningThe project folders contain course-specific information. Be sure to downloadthe one corresponding to your institution and course. - Launch IntelliJ via Finder → Applications → IntelliJ IDEA CE.app.
- When you launch IntelliJ for the first time,
- IntelliJ may displaytheJetBrains privacy policy.Scroll down and Accept.
- IntelliJ may ask if you want to send anonymous usage statistics to JetBrains. Choose your preferred option.
- To open a project from the Welcome screen,click Open and select the project folder.You should see an assignment logo (in the main editor window) and a list of project files (in the Project View sidebar at left).
When you launch IntelliJ for the first time,it may take a minute or two to index your files;some features (such as auto importing) will be unavailable until this process completes.WarningDo not select Create New Project;this option is intended for advanced programmers.Also, always use Open with a project folder, not an individual file. - When you are finished working, select the menu optionIntelliJ IDEA → Quit IntelliJ IDEA (⌘Q) to exit IntelliJ.The next time you launch IntelliJ, your recent projectswill appear in the Welcome screen for easy access.
2. Create a Program in IntelliJ |
Now you are ready to write your first Java program.IntelliJ features many specialized programming toolsincluding line numbering, syntax highlighting, bracket matching, auto indenting,auto formatting, auto importing, variable renaming, and continuous code inspection.
- To create a new Java program:
- Re-open IntelliJ and the project (if you closed it in the previous step).
- Click the project name in the Project View sidebar (at left), so that itbecomes highlighted.
- Select the menu option LIFT → New Java Class.When prompted, type HelloWorld for the Name and click OK.
- In the main editor window, complete the Java program
HelloWorld.java
exactly as it appears below.(IntelliJ generates the gray boilerplate code automatically,along with the course header block comment.)If you omit even a semicolon, the program won’t work. - As you type, IntelliJ highlights different syntactic elementsin different colors.When you type a left bracket, IntelliJ adds the matching right bracket.When you begin a new line, IntelliJ indents it.
- To save the file, select the menu option File → Save All (⌘S).When you save the file, IntelliJ re-formats it (if necessary).
3. Compile and Execute the Program (from IntelliJ) |
Now, it is time to execute (or run) your program.This is the exciting part, where your computer follows the instructionsspecified by your program.Before doing so, you must compile your program intoa form more amenable for execution on a computer.
- Select the program that you wish to compile and execute in the the Project View sidebar. The program should now appear in the main editor window.
- To compile your program,select the menu optionLIFT → Recompile 'HelloWorld.java' (⌘B).If the compilation succeeds, you will receive confirmationin the status bar (at bottom).If the compilation fails, a Recompile panel will open up (at bottom),highlighting the compile-time errors or warnings.Check your program carefully for typos, using the error messages as a guide.
- To execute your program,select the menu option LIFT → Run 'HelloWorld' with Arguments (⌘E).Since this program takes no command-line arguments, click OK.You should see the output of the program (in white), along with a messagethat the program finished normally (with exit code 0).
Tip
Use the LIFT menu to compile and execute your program from IntelliJ.The Build and Run menus support additional options for advanced programmers.
Also be sure that the main editor window is active before using the LIFTmenu (e.g., by clicking the code you want to compile or execute).
4. Compile and Execute the Program (from the command line) |
The command line is a simple and powerful mechanism forcontrolling your programs (e.g., command-line arguments,file redirection, and piping).IntelliJ supplies an embedded terminalfor easy access to the command line.
- Select the menu option View → Tool Windows → Terminal (⌘2).
- This will launch a Bash terminal where you type commands.You will see a command prompt that looks something like this:The
~/Desktop/hello
is the current working directory, where~
is shorthand for your home directory. - To compile your program,type the following
javac
command.More specifically, type the text in yellow that appears on the same line as thecommand prompt.Assuming that the fileHelloWorld.java
is in the current working directory,you should not see any compile-time errors or warnings. - To execute your program,type the following
java
command:You should see the output of your program beneath the line on which you typed the command.TipTypically, you should compile from IntelliJ(because IntelliJ highlights the lines on which anycompile-time errors or warnings occur) and execute from the command line(because the command line makes it is easy to specify command-line argumentsand use file redirection).
5. Textbook Libraries (from the command line) |
To make our textbook libraries accessible to Java from the command line,you will use our wrapper scripts.
- Computer Science: An Interdisciplinary Approach (including COS 126 students).The programBarnsley.javauses our standard drawing and standard random libraries in
stdlib.jar
to draw aBarnsley fern.First download Barnsley.java.Then, use the Finder to move itto a project folder (such ashello
).Finally, to compile and execute it,type the following commands in the terminal:When you execute the program, a standard drawing window will appearand an image like this one will be generated, one point at a time:To get your command prompt back, close the standard drawing window. - Algorithms, 4th Edition (including COS 226 and Coursera students).The programCollidingDisks.javauses various libraries in
algs4.jar
to simulate the motion of n disks subject to the lawsof elastic collision.First download CollidingDisks.javaThen, use the Finder to move it to a project folder (such aspercolation
).Finally, to compile and execute it,type the following commands in the terminal:When you execute the program, a standard drawing window will appearwith an animation of 20 colliding disks.To get your command prompt back, close the standard drawing window.Frequently Asked Questions - I installed IntelliJ and Java using the lift-java.pkg installerlast semester or year. Should I rerun this semester?
- Yes. This installer includes IntelliJ 2020.1and Java 11.The old installer may have used an earlier version of IntelliJ or Java.
- I previously used either the introcs.app or algs4.app installer.Should I use the lift-java.pkg installer?
- Yes. This installer includes IntelliJand Java 11 (instead of DrJava and Java 8).
- What happens if I rerun the lift-java.pkg installer?
- It will re-install and re-configure OpenJDK 11, IntelliJ,SpotBugs, PMD, Checkstyle, our textbook libraries,and wrapper scripts.
- The installer failed. How can I investigate why?
- Check the installer log at
/var/log/lift.log
. - I have Mac OS X 10.12 (Sierra). Is that too old?
- Yes.Yes. IntelliJ 2020.1 requires Mac OS X 10.13 (or newer).
- How long will the installer take to complete installation?
- Once downloaded, it should take about a minute.If you have anti-malware protection software running (such as McAfee Endpoint), it couldtake 5–10 minutes.
- What does the lift-java.pkg installer do?
- In short, it installs and configures Java, IntelliJ,SpotBugs,PMD,Checkstyle,and our textbook libraries,along with accompanying command-line tools.Here is a more detailed list:
- Installs OpenJDK 11.0.7.
- InstallsIntelliJ 2020.1.1with customized user preferences,available indepedently as lift-intellij.pkg.
- Installs the following command-line tools for Java, available independently aslift-cli.pkg.
- The textbook librariesstdlib.jar andalgs4.jar.
- Java wrapper scripts, includingjavac-algs4 and java-algs4.
- Custom.bashrc,.bash_profile, and.inputrc files.As a precaution, the installer will do this only if detects no preexistingbash configuration files.
- SpotBugs 4.0.3;our SpotBugs configuration file spotbugs.xml;and wrapper script spotbugs.
- PMD 6.15.0;our PMD configuration file pmd.xml;and wrapper script pmd.
- Checkstyle 8.31;various configuration files(checkstyle-cos126.xml,checkstyle-cos226.xml,checkstyle-coursera.xml, andcheckstyle-suppressions.xml);custom checks checkstyle-lift.jar;and wrapper script checkstyle.
- How is the software licensed?
- All of the included software is licensed under various open-source licenses.
- IntelliJ IDEA, Community Edition is licensed under theApache License, Version 2.0.
- OpenJDK 11 is licensed under theGNU General Public License,version 2, with the Classpath Exception.
- SpotBugs is licensed under theGNU Lesser Public License, Version 2.1.
- Checkstyle is licensed under theGNU Lesser Public License, Version 2.1.
- PMD is licensed under a BSD-style license.
- stdlib.jar and algs4.jar are licensed under theGNU General Public License, Version 3.
- What’s the sha256sum of lift-java.pkg?
e5ef947039280e0b0520fd7bd3aff8a0373719b96b1745c08a42441f6554fafe
- Can I run the installer from the command line?
- Yes. Use the command
sudo installer -verbose -pkg lift-java.pkg -target /
- How can I uninstall the software?
- To uninstall OpenJDK 11,delete the following directory:
/Library/Java/JavaVirtualMachines/jdk-11.0.7.jdk/
- To uninstall IntelliJ, delete the following:
/Applications/IntelliJ IDEA CE.app
~/Library/Application Support/JetBrains/IdeaIC2020.1/
~/Library/Caches/JetBrains/IdeaIC2020.1/
~/Library/Logs/JetBrains/IdeaIC2020.1/
- To uninstall SpotBugs, PMD, Checkstyle,and our textbook libraries, delete the following directory:
/usr/local/lift/
- To uninstall our wrapper scripts, delete the following files:
/usr/local/bin/javac-{algs4,introcs}
/usr/local/bin/java-{algs4,introcs}
/usr/local/bin/jshell-{algs4,introcs}
/usr/local/bin/spotbugs
/usr/local/bin/pmd
/usr/local/bin/checkstyle
- To uninstall OpenJDK 11,delete the following directory:
- Can I use a vendor and version of Java other than OpenJDK 11?
- Yes.You may use any version of Java 8, Java 9, Java 10, or Java 12, from either Oracle or OpenJDK.However, if you do so, you will need to manually configure the Platform SDK and Project SDK viaIntelliJ via File → Project Structure.
- How can I check which version of Java is installed (and where it is installed)?
- Type the following commands in the terminal:It’s important that the Java version numbers match and that you see the number
11
,but the rest is not critical. - How does this custom version of IntelliJ different from the standard one?
- IntelliJis an industrial-strength integrated development environment (IDE),suitable for use by professional programmers.The installer configures your user preferences to make itmore suitable for use by novice programmers:
- Disables all built-in plugins except Terminal and JUnit. Installs the SpotBugs, Checkstyle-IDEA, Run-with-Arguments, Save-Actions, and Archive browser plugins.
- Eliminates or reduces various popup elements (lightbulbs, code folding, breadcrumbs, gutter markers, notifications, parameter hints).
- Simplifies menus and toolbars, hiding advanced options.
- Disables live templates and postfix completion.
- Adopts the Obsidian Black color scheme.
- Auto-configures Java upon installation.
- Adds a few keyboard shortcuts.
The course-specific project folders perform additional customizations:- Streamlines autocomplete to display only relevant libraries(such as
java.lang
,java.util
, andalgs4.jar
). - Configures SpotBugs and Checkstyle with course-specific rules.
- Provides course-specific libraries (such as
algs4.jar
). - Enables auto-formatting of code on save.
- Enables auto-importing of Java libraries.
- How can I manually configure the Platform SDK and Project SDK in IntelliJ?
- The installer should configure the Platform SDK automatically.To configure it manually,
- Navigate to File → Project Structure → Platform Settings → SDKs.
- Click the + symbol (top left) to add an SDK.
- Locate an SDK. A typical location for a Java SDK onMac OS X is
/Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home/
. - Use the shorthand name suggested by IntelliJ(e.g., 11 for version 11.0.7).
To manually configure the Project SDK,- Navigate to File → Project Structure → Project Settings → Project.
- Choose the desired Project SDK from the drop-down list.
- Be sure to use 8 as the Project language level, as our autogradercurrently supports only Java 8 features.
- What are the most important IntelliJ menu options to remember?
- Here are the most important ones (and their shortcuts).
- LIFT → New Java Class (⌘N). Create a new Java class.
- LIFT → Recompile (⌘B). Compile the current program.
- LIFT → Run with Arguments (⌘E). Run the current program with command-line arguments.
- LIFT → Open in Terminal (⌘T). Open a new Terminal tab.
- File → Save All (⌘S). Save (and reformat) all open files.
- View → Tool Windows → Project (⌘1). Show/hide the Project View sidebar.
- View → Tool Windows → Terminal (⌘2). Show/hide the Terminal window.
- Any special characters to avoid when naming IntelliJ projects or files?
- Do not use an exclamation point (!) as the last characterin the project folder (or any directory name along the path to your project folder);that will confuse both IntelliJ and Checkstyle.
- How can I create a new project in IntelliJ?
- If you want to inherit all of the properties of an existing project,
- Use the Finder to copy the project folder,giving it your preferred name.
- Delete any unwanted files.
- Be sure to keepthe
.iml
file (which defines the project),the.idea
subdirectory (which containsthe IntelliJ course preferences), andthe.lift
subdirectory (which contains the courselibraries).
To create a new project from scratch, you can use the Create New Project option from theWelcome screen. But, we do not recommend this approach for novice programmers. - Can I use a version of IntelliJ that is more recent than 2020.1.1?
- Yes, though if it is 2020.2 (or above),you will need to migrate your user preferences.
- How I can I restore the original IntelliJ settings(instead of the abbreviated novice-friendly ones)?
- To restore the menus and toolbars: Preferences → Appearances & Behavior → Menus and Toolbars → Restore All Defaults.
- To restore all settings: Help → Find Action → Restore Default Settings.
- When I compile or execute a program from the command line that uses one of thetextbook libraries, I get an error that it cannot find the library. How can I fix this?
- Make sure that you are using the appropriate wrapper script,such as
javac-algs4
orjava-algs4
. - How should I configure Bash?
- If you followed our instructions, our wrapper scripts (such as
javac-algs4
andjava-algs4
)should already be available.Our autoinstaller customizes the command line in a few ways by copying these three configuration files:.bashrc
,.bash_profile
, and.inputrc
.Note that the autoinstaller will copy these files only if none of them already exists.If you had previous versions and wish to replace your versions with ours, type the following commands: - How do I break out of a program in an infinite loop?
- Type
Ctrl-C
. - How do I specify EOF to signal that standard input is empty?
- On Mac OS X and Linux, type
Enter
Ctrl-D
.On Windows, typeEnter
Ctrl-Z
Enter
,even in Git Bash. - How can I run SpotBugs, PMD, and Checkstyle from the command line?
- The installer includes wrapper scripts to simplify this process.
- To run SpotBugs 4.0.3, type the following command in the terminal:The argument must be a list of
.class
files.Here is a list ofbug descriptions. - To run PMD 6.15.0, type the following command in the terminal:The argument must be either a single
.java
file ora directory containing one or more.java
files.Here is a list of bug patterns. - To run Checkstyle 8.31, type one ofthe following commands in the terminal, depending on whether you are COS 126, COS 226, or Coursera student:The argument must be a list of
.java
files.Here is a list ofavailable checks.
- To run SpotBugs 4.0.3, type the following command in the terminal:The argument must be a list of
Java FAQCommand-Line / Embedded Terminal FAQ
Support for Java in Visual Studio Code is provided through a wide range of extensions. Combined with the power of core VS Code, these extensions give you a lightweight and performant code editor that also supports many of the most common Java development techniques.
This article will give you an overview of different capabilities of Visual Studio Code for Java developers. For a quick walkthrough of editing, running, and debugging a Java program with Visual Studio Code, use the button below.
Overview
VS Code provides essential language features such as code completion, refactoring, linting, formatting, and code snippets along with convenient debugging and unit test support. VS Code also integrates with tooling and frameworks such as Maven, Tomcat, Jetty, and Spring Boot. Leveraging the power of Visual Studio Code, Java developers get an excellent tool for both quick code editing and also the full debugging and testing cycle. It's a great choice for your Java work if you're looking for a tool which:
- Is fast, lightweight, free, and open source.
- Supports many other languages, not just Java.
- Helps start your Java journey without installing and learning a complex IDE.
- Provides great microservices support including popular frameworks, container tooling, and cloud integration.
- Offers team-based collaboration features such as Visual Studio Live Share.
- Improves your productivity through IntelliSense and other code-aware editing features.
Install Visual Studio Code for Java
VS Code is a fast editor and ships with great editing features. Before you begin, you must have the Java SE Development Kit (JDK) on your local environment. To run VS Code for Java, Java SE 11 or above version is required; for projects, VS Code for Java supports projects with version 1.5 or above. For more details, refer to Configure JDK.
To help you set up quickly, you can install the Coding Pack for Java, which includes VS Code, the Java Development Kit (JDK), and essential Java extensions. The Coding Pack can be used as a clean installation, or to update or repair an existing development environment.
Install the Coding Pack for Java - macOS
Note: The Coding Pack for Java is only available for Windows and macOS. For other operating systems, you will need to manually install a JDK, VS Code, and Java extensions.
Alternatively, you can also add Java language support to VS Code by installing the popular Java extensions by yourself.
Download VS Code - If you haven't downloaded VS Code yet, quickly install for your platform (Windows, macOS, Linux).
To help set up Java on VS Code, there is a Java Extension Pack, which contains the most popular extensions for most Java developers:
There are also other popular Java extensions you can pick for your own needs, including:
Thanks to the great Java community around VS Code, the list doesn't end there. You can search for more Java extensions easily within VS Code:
- Go to the Extensions view (⇧⌘X (Windows, Linux Ctrl+Shift+X)).
- Filter the extensions list by typing 'java'.
This document describes some of the key features included in those Java extensions.
Getting started
NOTE: If you are using VS Code on Windows and want to take advantage of the Windows Subsystem for Linux, see Developing in WSL.
For developers new to Java or new to VS Code, we provide a Getting Started experience. Once you've installed the Java Extension Pack, you can open the Getting Started experience from within VS Code with the Java: Getting Started command from the Command Palette. Open the Command Palette (⇧⌘P (Windows, Linux Ctrl+Shift+P)) and type 'Java: Getting Started'.
Working with Java source files
You can use VS Code to read, write, run, and debug Java source file(s) without creating a project. VS Code for Java supports two modes, lightweight and standard. Lightweight mode is ideal for scenarios that only deal with source file(s). If you want to work with a full scale project, standard mode will be required. You can easily switch from lightweight mode to standard mode, when needed. To learn more, see Lightweight Mode.
Working with Java project
There are three things you must understand to work with Java in VS Code:
- How does VS Code handle Workspaces?
- How does VS Code handle Java?
- How does VS Code handle Workspaces that contain Java?
VS Code Workspaces
In Visual Studio Code, a 'Workspace' means a collection of one or more filesystem folders (and their children) and all of the VS Code configurations that take effect when that 'Workspace' is open in VS Code. There are two kinds of 'Workspaces' in VS Code, 'folder workspaces' and 'multi-root workspaces'.
A 'folder workspace' is presented by VS Code when you open a filesystem folder (directory) in VS Code.
A 'multi-root workspace' can refer to multiple folders (directories) from disparate parts of the file system and VS Code displays the contents of the folder(s) of the workspace together in the File Explorer. To learn more, see Multi-root Workspaces.
Java project in VS Code
In contrast to IDEs such as IntelliJ IDEA, NetBeans, or Eclipse, the concept of a 'Java project' is provided entirely by extensions, and is not a core concept in the base VS Code. When working with 'Java projects' in VS Code, you must have the necessary extensions installed to work with those project files.
For example, Maven, Eclipse, and Gradle Java projects are supported through Language Support for Java(TM) by Red Hat, by utilizing M2Eclipse, which provides Maven support, and Buildship, which provides Gradle support through the Eclipse JDT Language Server.
With Maven for Java, you can generate projects from Maven Archetypes, browse through all the Maven projects within your workspace, and execute Maven goals easily from an embedded explorer. Projects can also be created and managed with the Project Manager for Java extension.
Visual Studio Code also supports working with standalone Java files outside of a Java project, described in the Java Tutorial with VS Code.
VS Code Workspaces that contain Java project
Assuming the necessary Java extensions are installed, opening a VS Code workspace that contains Java artifacts will cause those extensions to understand those artifacts and present options for working with them.
More details about Java project support can be found in Java Project Management in Visual Studio Code and Build Tools.
Editing
Code Navigation
Java in Visual Studio Code also supports source code navigation features such as search for symbol, Peek Definition, and Go to Definition. The Spring Boot Tools extension provides enhanced navigation and code completion support for Spring Boot projects.
One of the key advantages of VS Code is speed. When you open your Java source file or folder, within a few seconds, with the help of Lightweight Mode, you will be able to navigate your code base with Outline view as well as commands such as Go to Definition and Go to Reference. This is especially useful when you open a project for the first time.
Code Completion
IntelliSense is a general term for language features, including intelligent code completion (in-context method and variable suggestions) across all your files and for built-in and third-party modules. VS Code supports code completion and IntelliSense for Java through Language Support for Java(TM) by Red Hat. It also provides AI-assisted IntelliSense called IntelliCode by putting what you're most likely to use at the top of your completion list.
See also in Java Code Navigation and Editing. VS Code also supports a range of Refactoring and Linting features.
Debugging
Debugger for Java is a lightweight Java Debugger based on Java Debug Server. It works with Language Support for Java by Red Hat to allow users to debug Java code within Visual Studio Code.
Starting a debugging session is easy, click on the Run|Debug button available at the CodeLens of your
main()
function, or press F5. The debugger will automatically generate the proper configuration for you.Although it's lightweight, the Java debugger supports advanced features such as expression evaluation, conditional breakpoints, and hot code replacement. For more debugging related information, visit Java Debugging.
Testing
With the support from the Java Test Runner extension, you can easily run, debug, and manage your JUnit and TestNG test cases.
For more about testing, read Testing Java.
Spring Boot, Tomcat, and Jetty
To further improve your Java productivity in VS Code, there are extensions for most popular frameworks and tools such as Spring Boot, Tomcat, and Jetty created by the community.
The Tomcat extension includes an explorer to easily navigate and manage your Tomcat servers. You can create, start, debug, stop, and rename your Tomcat server with the extension.
See Application Servers to learn more about support for Tomcat and Jetty as well as other application servers with VS Code.
Spring Boot support is provided by Pivotal. There are also Spring Initializr Java Support and Spring Boot Dashboard extensions available from Microsoft to further improve your experience with Spring Boot in Visual Studio Code.
See Spring Boot with VS Code to learn more about Spring Boot support with VS Code.
Next steps
You may Sign up to follow the latest of Java on Visual Studio Code.
Learn more about Java in VS Code
Read on to find out more about Visual Studio Code:
Java Programming Language Download For Mac Windows 10
- Basic Editing - Learn about the powerful VS Code editor.
- Code Navigation - Move quickly through your source code.
- Tasks - use tasks to build your project and more
- Debugging - find out how to use the debugger with your project