如何在Linux中像Windows一样设置路径变量并全局配置JDK？

Hey there! Let's work through your Java setup questions on Linux—this is a super common pain point when you're getting multiple dev tools up and running, so you're definitely not alone here.

1. Ditch Multiple JDK Copies: Use a System-Wide Installation #

First off, you don't need to copy JDK into every app's directory! That's just wasting disk space and making it a nightmare to update later. The better approach is to set up a system-wide JDK that all your tools can share (or manage multiple versions cleanly if you need them).

• For Debian/Ubuntu-based distros: Install via your package manager with a command like:

  sudo apt install openjdk-17-jdk  # Swap 17 for 11, 8, etc., depending on your needs
  

• For RHEL/CentOS/Fedora: Use dnf instead:

  sudo dnf install java-17-openjdk-devel
  

• If you need to switch between multiple JDK versions (e.g., some apps need Java 8, others 17), use update-alternatives to manage them:
  1. Register each JDK version with:

     sudo update-alternatives --install /usr/bin/java java /path/to/your/jdk/bin/java 1
     

     Replace /path/to/your/jdk with the actual folder of your JDK, and adjust the priority number (higher = more preferred) as needed.
  2. Switch between versions anytime with:

     sudo update-alternatives --config java
     

     Just follow the prompt to pick the version you want to use globally.

2. Make java Work Everywhere in Terminal (Like Windows) #

This all boils down to setting up environment variables correctly—here's how to do it permanently:

1. First, find your JDK's installation path. If you installed via package manager, you can run update-alternatives --display java to get the full path (look for the "link currently points to" line). It'll look something like /usr/lib/jvm/java-17-openjdk-amd64.
2. Edit your shell's configuration file:
   • If you use Bash: Open ~/.bashrc with nano ~/.bashrc
   • If you use Zsh: Open ~/.zshrc with nano ~/.zshrc
3. Add these lines to the end of the file (replace the JAVA_HOME path with your actual one):

   export JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64
   export PATH=$PATH:$JAVA_HOME/bin
   

4. Save and exit (in nano: press Ctrl+O, hit Enter, then Ctrl+X).
5. Make the changes take effect immediately with:

   source ~/.bashrc  # Or source ~/.zshrc if you're using Zsh
   

Now you can open any terminal window, type java -version or javac -version, and it'll work without switching directories—just like on Windows!

3. Configure JDK for Sublime Text #

Sublime Text needs to know where your JDK is to compile and run Java code. You have two straightforward options:

Option 1: Custom Build System with Explicit JDK Path #

1. Open Sublime Text, go to Tools > Build System > New Build System.
2. Replace the default text with this configuration (update the JAVA_HOME path to match your setup):

   {
       "cmd": ["$JAVA_HOME/bin/javac", "$file_name", "&&", "$JAVA_HOME/bin/java", "$file_base_name"],
       "file_regex": "^(...*?):([0-9]*):?([0-9]*)",
       "selector": "source.java",
       "shell": true,
       "env": {"JAVA_HOME": "/usr/lib/jvm/java-17-openjdk-amd64"}
   }
   

3. Save the file as Java.sublime-build (save it in the default "User" directory that pops up).
4. Open your Java file, press Ctrl+B, and Sublime will compile and run it using your specified JDK.

Option 2: Use Your Global Environment Variables #

If you already set up the system-wide JAVA_HOME and PATH as we did earlier, you can simplify the build system to use the global javac and java commands directly:

{
    "cmd": ["javac", "$file_name", "&&", "java", "$file_base_name"],
    "file_regex": "^(...*?):([0-9]*):?([0-9]*)",
    "selector": "source.java",
    "shell": true
}

This way, Sublime will automatically use whichever JDK version you have set globally—no need to update the build system if you switch versions later.

内容的提问来源于stack exchange，提问作者nikk