Java - System.getenv() Examples

Java Java API 

Class:

java.lang.System

Methods:

public static String getenv(String name)

Returns the value of the specified environment variable. An environment variable is a system-dependent external named value.

The difference between system properties and environment variables is : properties are set for the currently running Java process, they are usually set as -Dname=value while running a Java program. Whereas, Environmental variables are set on O.S. level e.g. path variable, JAVA_HOME etc.

public static Map<String,String> getenv()

Returns an unmodifiable string map view of the current system environment. The environment is a system-dependent mapping from names to values which is passed from parent to child processes.

Examples

package com.logicbig.example.system;

import java.util.Map;

public class GetenvExample {

    public static void main(String... args) {
        Map<String, String> map = System.getenv();
        map.entrySet().forEach(System.out::println);
    }
}

Output

example-site-projects=D:\project\example-sentence-site
USERDOMAIN_ROAMINGPROFILE=JOEMSI
LG_BACKUP=G:\logicbig-backups\
GIT_HOME=D:\programs\Git
PROCESSOR_LEVEL=6
LG_RELEASE=C:\LogicBig-Release2
SESSIONNAME=Console
ALLUSERSPROFILE=C:\ProgramData
LogicBigDir=d:\LogicBig
PROCESSOR_ARCHITECTURE=AMD64
intellijPath=D:\programs\JetBrains\ideaIC-2025.2.3.win\bin
jvmConfig=\.mvn\jvm.config
PSModulePath=C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules
SystemDrive=C:
=ExitCode=00000001
MAVEN_HOME=D:\programs\maven\apache-maven-3.9.11
example-site-editor=D:\example-site-ws\example-site
USERNAME=joe2
ProgramFiles(x86)=C:\Program Files (x86)
WDIR=D:\
EFC_4696_1592913036=1
FPS_BROWSER_USER_PROFILE_STRING=Default
PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY;.PYW
DriverData=C:\Windows\System32\Drivers\DriverData
OneDriveConsumer=C:\Users\Joe\OneDrive
CLASSWORLDS_JAR="D:\programs\maven\apache-maven-3.9.11\boot\plexus-classworlds-2.9.0.jar"
projectsDrive=d:
ProgramData=C:\ProgramData
ProgramW6432=C:\Program Files
HOMEPATH=\Users\joe2
PROCESSOR_IDENTIFIER=Intel64 Family 6 Model 140 Stepping 1, GenuineIntel
M2_HOME=D:\programs\maven\apache-maven-3.9.11
ProgramFiles=C:\Program Files
PUBLIC=C:\Users\Public
windir=C:\WINDOWS
projectsDir=d:\projects
=::=::\
ZES_ENABLE_SYSMAN=1
LOCALAPPDATA=C:\Users\Joe\AppData\Local
ChocolateyLastPathUpdate=133939102610111551
USERDOMAIN=JOEMSI
FPS_BROWSER_APP_PROFILE_STRING=Internet Explorer
LOGONSERVER=\\JOEMSI
JAVA_HOME=D:\programs\java\jdk1.8.0_151
PROMPT=$P$G
ERROR_CODE=0
EXEC_DIR=D:\LogicBig\example-projects\java\java-core-api-snippets\java-lang
OneDrive=C:\Users\Joe\OneDrive
=C:=C:\Users\Joe
APPDATA=C:\Users\Joe\AppData\Roaming
ChocolateyInstall=C:\ProgramData\chocolatey
MAVEN_CMD_LINE_ARGS=-q compile -Dexec.mainClass="com.logicbig.example.system.GetenvExample" exec:java -Dexec.cleanupDaemonThreads=false
VBOX_MSI_INSTALL_PATH=C:\Program Files\Oracle\VirtualBox\
toolsDir=d:\tools
CommonProgramFiles=C:\Program Files\Common Files
Path=C:\Python\Python313\Scripts\;C:\Python\Python313\;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;D:\programs\java\jdk-17.0.4.1\bin;D:\programs\maven\apache-maven-3.9.11\bin;D:\programs\Git\cmd;D:\programs\node-v16.17.0-win-x64\;D:\projects\settings\bin;D:\programs\php-8.0.28-nts-Win32-vs16-x64;C:\ProgramData\chocolatey\bin;D:\programs\node\;C:\Users\Joe\AppData\Local\Programs\Python\Launcher\;C:\Users\Joe\AppData\Local\Microsoft\WindowsApps;C:\Users\Joe\AppData\Roaming\npm
OS=Windows_NT
COMPUTERNAME=JOEMSI
LG_PROJECTS_DRIVE=D:
JAVACMD=D:\programs\java\jdk1.8.0_151\bin\java.exe
MAVEN_PROJECTBASEDIR=D:\LogicBig\example-projects\java\java-core-api-snippets\java-lang
PROCESSOR_REVISION=8c01
CommonProgramW6432=C:\Program Files\Common Files
ComSpec=C:\WINDOWS\system32\cmd.exe
CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher
=D:=D:\LogicBig\example-projects\java\java-core-api-snippets\java-lang
SystemRoot=C:\WINDOWS
TEMP=C:\Users\Joe\AppData\Local\Temp
HOMEDRIVE=C:
USERPROFILE=C:\Users\Joe
TMP=C:\Users\Joe\AppData\Local\Temp
GitPath=d:\programs\Git
CommonProgramFiles(x86)=C:\Program Files (x86)\Common Files
LG_PROJECTS=D:\projects
NUMBER_OF_PROCESSORS=8

package com.logicbig.example.system;

public class GetenvExample2 {

    public static void main(String... args) {
        //not case sensitive
        String homePath = System.getenv("homePath");
        System.out.println(homePath);
    }
}

Output

\Users\joe2