Get java home variable

How to Set JAVA_HOME for JDK & JRE: A Step-by-Step Guide

This article was co-authored by wikiHow staff writer, Nicole Levine, MFA. Nicole Levine is a Technology Writer and Editor for wikiHow. She has more than 20 years of experience creating technical documentation and leading support teams at major web hosting and software companies. Nicole also holds an MFA in Creative Writing from Portland State University and teaches composition, fiction-writing, and zine-making at various institutions.

This article has been viewed 323,663 times.

Are you seeing Java errors like «JAVA_HOME is not defined correctly?» or «JAVA_HOME is set to an invalid directory?» If you’ve recently installed the Java Development Kit (JDK) or the Java Runtime Environment (JRE), you’ll need to set your JAVA_HOME variables and configure the path so applications know where to find Java. This wikiHow article will show you the easiest ways to change or set the Java home path on Windows, macOS, and Linux.

• Before you can set JAVA_HOME, you’ll need the full path to your JDK or JRE installation.
• Once you set the JAVA_HOME environment variable, you can run the command echo $JAVA_HOME to see the new path.
• To set the Java home and path on Linux or macOS permanently (even after a reboot), add the environment variables to your .bashrc or .zshrc file.

Windows

• Open File Explorer, click This PC in the left panel, then navigate to C:\Program Files\Java. The directory you’re looking for should have the name of the JDK version, such as C:\Program Files\Java\jdk-19.
• If you installed the JRE instead of the JDK, you’ll have something like C:\Program Files\Java\jre1.8.0_351 instead.
• You can also open the command prompt and run the command wmic product where «Name like ‘%%Java%%'» get installlocation,Name . This will tell you the full path of the JDK, even if you haven’t yet set JAVA_HOME.

• Press the Windows key on your keyboard and type advanced system .
• Click View advanced system settings in the search results.

Click the Environment Variables button. You’ll see it at the bottom-right corner of the System Properties window.

• If you have multiple installations of the JDK and want to change JAVA_HOME to your new installation, select the current JAVA_HOME user variable and click Edit… instead.

• If you’re editing the current JAVA_HOME path, you’ll already have JAVA_HOME here. So, you can skip this step.

• If you’re adding a second path to JAVA_HOME, just type a semicolon (;) after the first path, then enter the second path.
• If you’re replacing an old JAVA_HOME path, just delete the current path and enter the new one.

• If you want other users on this PC to be able to access Java binaries from the command line, repeat this step for the «Path» variable under «System variables» as well.

• Click the New button at the top.
• Enter the full path to the JRE or JDK with \bin at the end. For example, C:\Program Files\Java\jdk-19\bin or C:\Program Files\Java\jre1.8.0_351\bin.
• Click OK.

• You won’t need to restart your computer for the changes to take effect, but you will need to relaunch any apps that were trying to access Java.
• Open a new command prompt window and run the command echo %JAVA_HOME% to display the new path to JAVA_HOME.
  • Make sure this is a new command prompt window. If you still have the same window open, the command will fail because it doesn’t have the new environment variables.

  macOS

  

  Open a Terminal window. To open Terminal, search for Terminal in Spotlight. Or, you can open Finder, click the Go menu, select Utilities, and choose the Terminal app.

  

  • If you have more than one Java installation and want to see the paths to all of them, use /usr/libexec/java_home -V instead.

  

  Copy the path and paste it somewhere handy. Highlight the path to the Java installation you want to use as JAVA_HOME, press Cmd + V to copy it, then paste it into a sticky note or text file.

  

  • Type cd ~ and press Return.
  • Type open .zshrc and press Return. This should open the file in a text editor.
  • If the file is not found, type echo > .zshrc and press Return. Then, run open .zshrc again.

  

  • export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-17.0.1.jdk/Contents/Home
    • Replace /Library/Java/JavaVirtualMachines/jdk-17.0.1.jdk/Contents/Home with the full path to the /Contents/Home directory of your Java installation if it’s different.

    

    Type source .zshrc and press ⏎ Return . Once you’ve edited your profile, this command ensures that your environment variables will be updated for the current terminal window (and any other windows you open from now on).

    

    • If you had any other windows open that were attempting to find Java binaries, close and reopen them.
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    Linux

    

    

    • readlink -f `which javac`
    • If that doesn’t work, try running update-alternatives —list java .
    • If neither of these commands works, run whereis java , which will usually result in a symbolic link like /usr/bin/java.
      • Once you get the directory, find out where it links using ls -la /bin/java .
      • If that points you to another directory, e.g., /etc/alternatives/java, run ls -la /etc/alternatives/java .
      • At that point, you should see a much longer directory, which is actually the home to the Java binaries. For example, usr/lib/jvm/java-11-openjdk-arm64/bin/java . This is the directory you want.

      

      • echo «export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-arm64» >> ~/.bashrc
      • echo «export PATH=$PATH:$JAVA_HOME/bin» >> ~/.bashrc

      

      Expert Q&A

      In Linux, you can set JAVA__HOME for all users by editing the global .bashrc, which is located at /etc/bash.bashrc. Just use echo and replace ~/.bashrc with /etc/bash.bashrc .

      

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      This article was co-authored by wikiHow staff writer, Nicole Levine, MFA. Nicole Levine is a Technology Writer and Editor for wikiHow. She has more than 20 years of experience creating technical documentation and leading support teams at major web hosting and software companies. Nicole also holds an MFA in Creative Writing from Portland State University and teaches composition, fiction-writing, and zine-making at various institutions. This article has been viewed 323,663 times.

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      1. Introduction

      In this quick tutorial, we’ll learn how to find JAVA_HOME on Windows, Mac, and Linux.

      As we all know, JAVA_HOME is an environment variable that we commonly use to locate java executables, like java and javac.

      2. Windows-Specific Ways to Find JAVA_HOME

      If we’re using Windows as the operating system, first we need to open up our command line (cmd) and type:

      If JAVA_HOME is defined in our environment, then the above command will print it out.

      Or to show the location of the java executable, we can try:

      3. macOS and Linux-Specific Ways to Find JAVA_HOME

      If we’re using either macOS or Linux, we can open up our terminal and type:

      If JAVA_HOME is defined in our environment, then the above command will print it out.

      This probably just shows us /usr/bin/java, which really isn’t very helpful since it’s a symbolic link. To unravel this, we’ll use dirname and readlink.

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      This command prints the currently used java folder.

      4. Using Java to Find JAVA_HOME

      If we’re able to run java ourselves, then we have a nearly platform-independent way as well:

      java -XshowSettings:properties -version

      Running this command outputs numerous properties, one of them being java.home.

      To parse it though, we’ll still need a platform-specific tool.

      For Linux and macOS, we’ll use grep:

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      java -XshowSettings:properties -version 2>&1 | findstr "java.home"

      5. Conclusion

      In this brief article, we learned how to find JAVA_HOME on different operating systems.

      If this didn’t work though, it’s possible we didn’t set the JAVA_HOME variable properly while installing Java.

      

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