JVM and OS System Properties

Java Tutorials - Herong's Tutorial Examples

∟System Properties and Runtime Object Methods

∟JVM and OS System Properties

This section provides a tutorial example on how to list all properties from the JVM and the OS that are accessible by your Java application.

Java application programs are executed inside a Java Virtual Machine (JVM), which is in turn executed inside an Operating System (OS). From the Java application program point of view, the JVM, together with the OS, represents the computer system. The properties of the JVM and the OS are all called system properties.

A Java application program can:

Use System.getProperty(String propertyName) to get the value of a specific system property.
Use System.getProperties() to get all available system properties.

Here is an example program that displays the values of all available system properties:

/* SysProperties.java
 * Copyright (c) HerongYang.com. All Rights Reserved.
 */
import java.util.*;
public class SysProperties {
   public static void main(String[] a) {
      Properties sysProps = System.getProperties();
      sysProps.list(System.out);
   }
}

Output:

-- listing properties --
java.specification.version=17
sun.cpu.isalist=amd64
sun.jnu.encoding=Cp1252
java.class.path=.
java.vm.vendor=Oracle Corporation
sun.arch.data.model=64
user.variant=
java.vendor.url=https://java.oracle.com/
java.vm.specification.version=17
os.name=Windows 10
sun.java.launcher=SUN_STANDARD
user.country=US
sun.boot.library.path=C:\Progra~1\java\jdk-17.0.1\bin
sun.java.command=jdk.compiler/com.sun.tools.javac.laun...
jdk.debug=release
sun.cpu.endian=little
user.home=C:\Users\herong
user.language=en
sun.stderr.encoding=ms936
java.specification.vendor=Oracle Corporation
java.version.date=2021-10-19
java.home=C:\Progra~1\java\jdk-17.0.1
file.separator=\
java.vm.compressedOopsMode=32-bit
line.separator=

sun.stdout.encoding=ms936
java.vm.specification.vendor=Oracle Corporation
java.specification.name=Java Platform API Specification
jdk.module.main.class=com.sun.tools.javac.launcher.Main
user.script=
sun.management.compiler=HotSpot 64-Bit Tiered Compilers
java.runtime.version=17.0.1+12-LTS-39
user.name=herong

jdk.launcher.sourcefile=C:\herong\SysProperties.java
path.separator=;
os.version=10.0
java.runtime.name=Java(TM) SE Runtime Environment
file.encoding=Cp1252
java.vm.name=Java HotSpot(TM) 64-Bit Server VM
java.vendor.url.bug=https://bugreport.java.com/bugreport/
java.io.tmpdir=C:\Users\herong\AppData\Local\Temp\
java.version=17.0.1
user.dir=C:\herong
os.arch=amd64
java.vm.specification.name=Java Virtual Machine Specification
sun.os.patch.level=
native.encoding=Cp1252
java.library.path=C:\Progra~1\java\jdk-17.0.1\bin;C:\Wi...
java.vm.info=mixed mode, sharing
java.vendor=Oracle Corporation
java.vm.version=17.0.1+12-LTS-39
sun.io.unicode.encoding=UnicodeLittle
java.class.version=61.0

Note that:

The value of property "line.separator" contains a new line character '\n', which produces a blank line on the output window.
The Properties.list() truncates values after 37 characters while sending them to the output stream.