How to set the environment variables for Java in Windows

Windows Client (10, 11, 12) Performance & Dépannage
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How to set the environment variables for Java in Windows

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Java SE Development Kit 8u112 on a 64-bit Windows 7 or Windows 8

Set the following user environment variables (== environment variables of type user variables)

  • JAVA_HOME : C:\Program Files\Java\jdk1.8.0_112

  • JDK_HOME : %JAVA_HOME%

  • JRE_HOME : %JAVA_HOME%\jre

  • CLASSPATH : .;%JAVA_HOME%\lib;%JAVA_HOME%\jre\lib

  • PATH : your-unique-entries;%JAVA_HOME%\bin (make sure that the longish your-unique-entries does not contain any other references to another Java installation folder.

Note for Windows users on 64-bit systems:

Progra~1 = 'Program Files'
Progra~2 = 'Program Files(x86)'

Notice that these environment variables are derived from the “root” environment variable JAVA_HOME. This makes it easy to update your environment variables when updating the JDK. Just point JAVA_HOME to the fresh installation.

There is a blogpost explaining the rationale behind all these environment variables.

Optional recommendations

  • Add a user environment variable JAVA_TOOL_OPTIONS with value -Dfile.encoding="UTF-8". This ensures that Java (and tools such as Maven) will run with a Charset.defaultCharset() of UTF-8 (instead of the default Windows-1252). This has saved a lot of headaches when wirking with my own code and that of others, which unfortunately often assume the (sane) default encoding UTF-8.

  • When JDK is installed, it adds to the system environment variable Path an entry C:\ProgramData\Oracle\Java\javapath;. I anecdotally noticed that the links in that directory didn’t get updated during an JDK installation update. So it’s best to remove C:\ProgramData\Oracle\Java\javapath; from the Path system environment variable in order to have a consistent environment.