Understanding Path & JAVA_HOME

Contents

• What is Path for?
• JAVA_HOME
• How would I change which Java my OS tries using?

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What is Path for?

Path is a list of directories that contain executable programs

When you run a command, such as

java -version

Your OS will look through the directories specified on the path for a program named java

You can find the location of the program by running the following command

• Windows

where java

• Linux & Mac

whereis java

If a folder containing Java is not defined on the Path...

• Running java commands will display an error message "Cannot be found" or "Is not installed"

• Running where commands will display an error message "Cannot find the files" or a blank path (such as java: with no actual value)

• Double clicking a JAR file may result in nothing happening (since Java isn't properly installed)

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Viewing what's on your system's Path

Open the terminal/command prompt on your machine

• Windows (not case sensitive)

echo %path%

TODO- Include UI view

• Linux & Mac (case sensitive)

$PATH

TODO - Include scoping

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JAVA_HOME

TODO - Explain why JAVA_HOME is required by some programs

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How would I change which Java my OS tries using?

TODO - Explain path priority