SystemUtils

About

SystemUtils is a utility class provided by Apache Commons Lang for accessing system-related information such as:

• Java runtime version

• Operating system details

• File system properties

• User environment details

• Temporary and user directories

Java’s built-in System.getProperty() works well, but it's verbose and lacks consistency. SystemUtils provides a clean, constant-based, and null-safe way to retrieve environment and system properties.

Characteristics

• All fields and methods are static.

• Offers system-level constants for Java and OS properties.

• Safer alternative to System.getProperty(...).

• Commonly used in logging, debugging, platform-specific behavior, and testing.

Maven Dependency & Import

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.12.0</version> <!-- or latest -->
</dependency>

import org.apache.commons.lang3.SystemUtils;

Commonly Used Constants and Methods

1. Java Version Information

Constant	Description
JAVA_VERSION	Java version (e.g., "17" or "1.8.0_321")
JAVA_VERSION_FLOAT	Java version as float
JAVA_VERSION_TRIMMED	Trimmed version (e.g., "17", "11", "1.8")
JAVA_VENDOR	Java vendor (e.g., "Oracle Corporation")
JAVA_VENDOR_URL	Vendor URL
JAVA_HOME	Path to installed Java home

Example:

System.out.println(SystemUtils.JAVA_VERSION); // e.g., "17.0.2"

2. Operating System Details

Constant	Description
OS_NAME	OS name (e.g., "Windows 10")
OS_VERSION	OS version
OS_ARCH	Architecture ("x86", "amd64")
IS_OS_WINDOWS	Boolean flag if Windows
IS_OS_LINUX	Boolean flag if Linux
IS_OS_MAC	Boolean flag if macOS

Example:

if (SystemUtils.IS_OS_WINDOWS) {
    // Windows-specific code
}

3. User Environment Details

Constant	Description
USER_NAME	System username
USER_HOME	Home directory path
USER_DIR	Working directory
TMP_DIR	Temporary directory
LINE_SEPARATOR	OS-specific newline ( or \r)

Example:

String tmpPath = SystemUtils.TMP_DIR;

4. File System Properties

Constant	Description
FILE_SEPARATOR	OS file separator ("/" or "\\")
PATH_SEPARATOR	OS path separator (":" or ";")
LINE_SEPARATOR	OS-specific new line

These help write cross-platform file-handling logic.

Why Use SystemUtils Instead of System.getProperty()?

Concern	System.getProperty()	SystemUtils Advantage
Null safety	Returns null, needs checking	Safe constants and clear names
Readability	"os.name", "java.version" unclear	SystemUtils.OS_NAME is self-explanatory
Constants & flags	Must write logic manually	Provides IS_OS_* flags directly
Duplication	Often repeated keys in code	Centralized and standardized references