Run java command on linux

Run Java Programs on Linux Using Command Line: A Comprehensive Guide

Learn how to run Java programs on Linux using the command line. Follow our step-by-step guide to install JDK, compile and run Java programs, troubleshoot common issues, and stay up-to-date with the latest advancements in Java.

• Introduction
• Installing the Java Development Kit (JDK)
• How to Run Java Program in Terminal Ubuntu Linux
• Navigating to the Directory Where the Java Program is Saved
• Compiling the Java Program Using the javac Command
• Running the Java Program Using the java Command
• Setting Up the Java Path Correctly
• Running Java Programs from Within Other Java Programs
• Common Issues While Running Java Programs on Linux
• Advantages and Disadvantages of Running Java Programs from the Command Line
• Latest Advancements in Java
• Other Java code examples for running Java programs using the command line on Linux
• Conclusion
• How to run Java file from command line?
• How do I run a Java file in Unix?
• How do I run a Java file in Ubuntu?
• How do I run a jar file in Linux?

As a software developer or IT professional, you may need to run Java programs using the command line on a Linux system. This can be useful in situations where you need to automate tasks or run programs without a graphical interface. This article will provide a comprehensive guide on how to run Java programs using the command line on a Linux system.

Introduction

Running Java Programs on Linux using the command line has several advantages, such as being able to automate tasks and run programs without a graphical interface. In this article, we will cover the key points, important points, and helpful tips that you need to know to run Java programs on Linux using the command line.

Installing the Java Development Kit (JDK)

Before you can run Java programs on Linux using the command line, you need to have the Java Development Kit (JDK) installed on your system. Here are the steps to install the JDK on a Linux system:

1. Open a terminal window.
2. Enter the command sudo apt-get install default-jdk to install the default JDK package.
3. Verify that the JDK is installed by entering the command java -version .

How to Run Java Program in Terminal Ubuntu Linux

In this video I am going to show you How to install Java JDK 10 on Ubuntu Linux ( with Duration: 11:41

Navigating to the Directory Where the Java Program is Saved

Once you have installed the JDK, the next step is to navigate to the directory where the Java program is saved. Here are the steps to navigate to the directory:

1. Open a terminal window.
2. Enter the command cd /path/to/directory to navigate to the directory where the Java program is saved.

It is important to organize and save your Java programs in a logical and easy-to-find manner, so that you can easily navigate to the directory where the programs are saved.

Compiling the Java Program Using the javac Command

After navigating to the directory where the Java program is saved, the next step is to compile the program using the javac command. Here are the steps to compile the Java program:

1. Open a terminal window.
2. Navigate to the directory where the Java program is saved using the cd command.
3. Enter the command javac filename.java to compile the Java program.

While compiling Java programs on Linux, some common issues may arise, such as compilation errors due to syntax errors or missing libraries. These issues can be resolved by carefully reviewing the error messages and making necessary corrections.

Running the Java Program Using the java Command

After compiling the Java program, the next step is to run the program using the java command. Here are the steps to run the compiled Java program:

1. Open a terminal window.
2. Navigate to the directory where the Java program is saved using the cd command.
3. Enter the command java filename to run the compiled Java program.

It is also possible to execute the .class file using the java command, by entering the command java classname .

Setting Up the Java Path Correctly

To run Java programs on Linux using the command line, it is important to set up the Java path correctly. Here are the steps to set up the Java path correctly:

1. Open a terminal window.
2. Enter the command sudo nano /etc/environment .
3. Add the following lines to the file:

JAVA_HOME="/usr/lib/jvm/default-java" PATH="$PATH:$JAVA_HOME/bin" 

Setting up the Java path correctly ensures that the Java programs can be executed from any directory on the system.

Running Java Programs from Within Other Java Programs

It is also possible to run Java programs from within other Java programs using the Runtime.exec() method. Here are the steps to execute Java programs from within other Java programs:

1. Create a Process object using the Runtime.exec() method.
2. Use the getInputStream() method to read the output of the executed program.
3. Use the waitFor() method to wait for the program to finish executing.

When Running Java programs from within other Java programs, it is important to follow best practices, such as using a separate thread to read the output of the executed program and handling any errors that may arise.

Common Issues While Running Java Programs on Linux

While running Java programs on Linux using the command line, some common issues may arise, such as errors due to missing libraries or incorrect permissions. These issues can be resolved by carefully reviewing the error messages and making necessary corrections.

Advantages and Disadvantages of Running Java Programs from the Command Line

running java programs from the command line on Linux has several advantages, such as being able to automate tasks and run programs without a graphical interface. However, there are also disadvantages, such as the lack of a graphical interface and the need to have knowledge of command line syntax. To maximize the advantages and minimize the disadvantages, it is important to have a good understanding of the command line syntax and to use best practices when running Java programs from the command line.

Latest Advancements in Java

Java is a constantly evolving language, with new features and advancements being introduced with each release. Some of the latest advancements in java include the release of Java 16 and the introduction of new features such as sealed classes and pattern matching. To stay up-to-date with the latest advancements in Java, it is important to regularly check for updates and to read blogs and articles on the topic.

Other Java code examples for running Java programs using the command line on Linux

In Java as proof, java run linux command

Process p = Runtime.getRuntime().exec("ls -la /home"); BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getOutputStream())); String result; while ((result = stdInput.readLine()) != null)

In Java as proof, run java from terminal linux code sample

//To compile, type javac filename.java//To run the generated class file, use java filename

In Java as proof, how to run a java file in terminal code example

javac FirstJavaProgram.java

Conclusion

Running Java programs on Linux using the command line can be a useful skill for software developers and IT professionals. In this article, we have provided a comprehensive guide on how to run Java programs using the command line on a Linux system. By following the steps outlined in this article and using best practices, you can successfully run Java programs on Linux using the command line.

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How to Run Java Programs in Ubuntu

So, you have started learning Java programming? That’s good.

And you want to run the java programs on your Linux system? Even better.

Let me show how to run Java in terminal in Ubuntu and other Linux distributions.

Running Java programs in Ubuntu

Let’s go in proper steps here.

Step 1: Install Java compiler

To run a Java program, you need to compile the program first. You need Java compiler for this purpose.

The Java compiler is part of JDK (Java Development Kit). You need to install JDK in order to compile and run Java programs.

First, check if you already have Java Compiler installed on your system:

If you see an error like “Command ‘javac’ not found, but can be installed with”, this means you need to install Java Development Kit.

The simplest way to install JDK on Ubuntu is to go with the default offering from Ubuntu:

sudo apt install default-jdk

You’ll be asked to enter your account’s password. When you type the password, nothing is seen on the screen. That is normal. Just enter your password blindly. When asked, press the enter key or Y key.

The above command should work for other Debian and Ubuntu based distributions like Linux Mint, elementary OS etc. For other distributions, use your distribution’s package manager. The package name could also be different.

Once installed, verify that javac is available now.

Step 2: Compile Java program in Linux

You need to have a Java program file for this reason. Let’s say you create a new Java program file named HelloWorld.java and it has the following content:

You can use Nano editor in terminal or Gedit graphical text editor for writing your Java programs.

If there is no error, the above command produces no output.

When you compile the Java program, it generates a .class file with the class name you used in your program. You have to run this class file.

Step 3: Run the Java class file

You do not need to specify the class extension here. Just the name of the class. And this time, you use the command java, not javac.

This will print Hello World on the screen for my program.

And that’s how you run a Java program in the Linux terminal.

This was the simplest of the example. The sample program had just one class. The Java compiler creates a class file for each class in your program. Things get complicated for bigger programs and projects.

This is why I advise installing Eclipse on Ubuntu for proper Java programming. It is easier to program in an IDE.

I hope you find this tutorial helpful. Questions or suggestions? The comment section is all yours.

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