Package org.apache.commons.lang3

Class SystemUtils

java.lang.Object
org.apache.commons.lang3.SystemUtils
public class SystemUtils extends Object
Helpers for System.

If a system property cannot be read due to security restrictions, the corresponding field in this class will be set to null and a message will be written to System.err.

#ThreadSafe#

Since:
1.0
See Also:

  • Field Details

    • FILE_ENCODING

      public static final String FILE_ENCODING
      The file.encoding System Property.

      File encoding, such as Cp1252.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.2
      See Also:

    • FILE_SEPARATOR

      @Deprecated public static final String FILE_SEPARATOR
      Deprecated.
      Use File.separator, since it is guaranteed to be a string containing a single character and it does not require a privilege check.
      The file.separator System Property. The file separator is:
      • "/" on UNIX
      • "\" on Windows.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_AWT_FONTS

      public static final String JAVA_AWT_FONTS
      The java.awt.fonts System Property.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1
      See Also:

    • JAVA_AWT_GRAPHICSENV

      public static final String JAVA_AWT_GRAPHICSENV
      The java.awt.graphicsenv System Property.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1
      See Also:

    • JAVA_AWT_HEADLESS

      public static final String JAVA_AWT_HEADLESS
      The java.awt.headless System Property. The value of this property is the String "true" or "false".

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1, Java 1.4
      See Also:

    • JAVA_AWT_PRINTERJOB

      public static final String JAVA_AWT_PRINTERJOB
      The java.awt.printerjob System Property.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1
      See Also:

    • JAVA_CLASS_PATH

      public static final String JAVA_CLASS_PATH
      The java.class.path System Property. Java class path.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_CLASS_VERSION

      public static final String JAVA_CLASS_VERSION
      The java.class.version System Property. Java class format version number.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_COMPILER

      public static final String JAVA_COMPILER
      The java.compiler System Property. Name of JIT compiler to use. First in JDK version 1.2. Not used in Sun JDKs after 1.2.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2. Not used in Sun versions after 1.2.
      See Also:

    • JAVA_ENDORSED_DIRS

      public static final String JAVA_ENDORSED_DIRS
      The java.endorsed.dirs System Property. Path of endorsed directory or directories.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.4
      See Also:

    • JAVA_EXT_DIRS

      public static final String JAVA_EXT_DIRS
      The java.ext.dirs System Property. Path of extension directory or directories.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.3
      See Also:

    • JAVA_HOME

      public static final String JAVA_HOME
      The java.home System Property. Java installation directory.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_IO_TMPDIR

      public static final String JAVA_IO_TMPDIR
      The java.io.tmpdir System Property. Default temp file path.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_LIBRARY_PATH

      public static final String JAVA_LIBRARY_PATH
      The java.library.path System Property. List of paths to search when loading libraries.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_RUNTIME_NAME

      public static final String JAVA_RUNTIME_NAME
      The java.runtime.name System Property. Java Runtime Environment name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.3
      See Also:

    • JAVA_RUNTIME_VERSION

      public static final String JAVA_RUNTIME_VERSION
      The java.runtime.version System Property. Java Runtime Environment version.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.3
      See Also:

    • JAVA_SPECIFICATION_NAME

      public static final String JAVA_SPECIFICATION_NAME
      The java.specification.name System Property. Java Runtime Environment specification name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_SPECIFICATION_VENDOR

      public static final String JAVA_SPECIFICATION_VENDOR
      The java.specification.vendor System Property. Java Runtime Environment specification vendor.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_SPECIFICATION_VERSION

      public static final String JAVA_SPECIFICATION_VERSION
      The java.specification.version System Property. Java Runtime Environment specification version.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.3
      See Also:

    • JAVA_UTIL_PREFS_PREFERENCES_FACTORY

      public static final String JAVA_UTIL_PREFS_PREFERENCES_FACTORY
      The java.util.prefs.PreferencesFactory System Property. A class name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1, Java 1.4
      See Also:

    • JAVA_VENDOR

      public static final String JAVA_VENDOR
      The java.vendor System Property. Java vendor-specific string.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_VENDOR_URL

      public static final String JAVA_VENDOR_URL
      The java.vendor.url System Property. Java vendor URL.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_VERSION

      public static final String JAVA_VERSION
      The java.version System Property. Java version number.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • JAVA_VM_INFO

      public static final String JAVA_VM_INFO
      The java.vm.info System Property. Java Virtual Machine implementation info.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.2
      See Also:

    • JAVA_VM_NAME

      public static final String JAVA_VM_NAME
      The java.vm.name System Property. Java Virtual Machine implementation name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_VM_SPECIFICATION_NAME

      public static final String JAVA_VM_SPECIFICATION_NAME
      The java.vm.specification.name System Property. Java Virtual Machine specification name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_VM_SPECIFICATION_VENDOR

      public static final String JAVA_VM_SPECIFICATION_VENDOR
      The java.vm.specification.vendor System Property. Java Virtual Machine specification vendor.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_VM_SPECIFICATION_VERSION

      public static final String JAVA_VM_SPECIFICATION_VERSION
      The java.vm.specification.version System Property. Java Virtual Machine specification version.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_VM_VENDOR

      public static final String JAVA_VM_VENDOR
      The java.vm.vendor System Property. Java Virtual Machine implementation vendor.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • JAVA_VM_VERSION

      public static final String JAVA_VM_VERSION
      The java.vm.version System Property. Java Virtual Machine implementation version.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.2
      See Also:

    • LINE_SEPARATOR

      @Deprecated public static final String LINE_SEPARATOR
      Deprecated.
      Use System.lineSeparator() instead, since it does not require a privilege check.
      The line.separator System Property. Line separator ("\n" on UNIX).

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • OS_ARCH

      public static final String OS_ARCH
      The os.arch System Property. Operating system architecture.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • OS_NAME

      public static final String OS_NAME
      The os.name System Property. Operating system name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • OS_VERSION

      public static final String OS_VERSION
      The os.version System Property. Operating system version.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • PATH_SEPARATOR

      @Deprecated public static final String PATH_SEPARATOR
      Deprecated.
      Use File.pathSeparator, since it is guaranteed to be a string containing a single character and it does not require a privilege check.
      The path.separator System Property. Path separator (":" on UNIX).

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • USER_COUNTRY

      public static final String USER_COUNTRY
      The user.country or user.region System Property. User's country code, such as "GB". First in Java version 1.2 as user.region. Renamed to user.country in 1.4

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.2

    • USER_DIR

      public static final String USER_DIR
      The user.dir System Property. User's current working directory.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • USER_HOME

      public static final String USER_HOME
      The user.home System Property. User's home directory.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • USER_LANGUAGE

      public static final String USER_LANGUAGE
      The user.language System Property. User's language code, such as "en".

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.0, Java 1.2
      See Also:

    • USER_NAME

      public static final String USER_NAME
      The user.name System Property. User's account name.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      Java 1.1
      See Also:

    • USER_TIMEZONE

      public static final String USER_TIMEZONE
      The user.timezone System Property. For example: "America/Los_Angeles".

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1
      See Also:

    • IS_JAVA_1_1

      public static final boolean IS_JAVA_1_1
      Is true if this is Java version 1.1 (also 1.1.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_2

      public static final boolean IS_JAVA_1_2
      Is true if this is Java version 1.2 (also 1.2.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_3

      public static final boolean IS_JAVA_1_3
      Is true if this is Java version 1.3 (also 1.3.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_4

      public static final boolean IS_JAVA_1_4
      Is true if this is Java version 1.4 (also 1.4.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_5

      public static final boolean IS_JAVA_1_5
      Is true if this is Java version 1.5 (also 1.5.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_6

      public static final boolean IS_JAVA_1_6
      Is true if this is Java version 1.6 (also 1.6.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

    • IS_JAVA_1_7

      public static final boolean IS_JAVA_1_7
      Is true if this is Java version 1.7 (also 1.7.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.0

    • IS_JAVA_1_8

      public static final boolean IS_JAVA_1_8
      Is true if this is Java version 1.8 (also 1.8.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.3.2

    • IS_JAVA_1_9

      @Deprecated public static final boolean IS_JAVA_1_9
      Deprecated.
      As of release 3.5, replaced by IS_JAVA_9
      Is true if this is Java version 1.9 (also 1.9.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_JAVA_9

      public static final boolean IS_JAVA_9
      Is true if this is Java version 9 (also 9.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.5

    • IS_JAVA_10

      public static final boolean IS_JAVA_10
      Is true if this is Java version 10 (also 10.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.7

    • IS_JAVA_11

      public static final boolean IS_JAVA_11
      Is true if this is Java version 11 (also 11.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.8

    • IS_JAVA_12

      public static final boolean IS_JAVA_12
      Is true if this is Java version 12 (also 12.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.9

    • IS_JAVA_13

      public static final boolean IS_JAVA_13
      Is true if this is Java version 13 (also 13.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.9

    • IS_JAVA_14

      public static final boolean IS_JAVA_14
      Is true if this is Java version 14 (also 14.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.10

    • IS_JAVA_15

      public static final boolean IS_JAVA_15
      Is true if this is Java version 15 (also 15.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.10

    • IS_JAVA_16

      public static final boolean IS_JAVA_16
      Is true if this is Java version 16 (also 16.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_17

      public static final boolean IS_JAVA_17
      Is true if this is Java version 17 (also 17.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_18

      public static final boolean IS_JAVA_18
      Is true if this is Java version 18 (also 18.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_19

      public static final boolean IS_JAVA_19
      Is true if this is Java version 19 (also 19.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_20

      public static final boolean IS_JAVA_20
      Is true if this is Java version 20 (also 20.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_21

      public static final boolean IS_JAVA_21
      Is true if this is Java version 21 (also 21.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_JAVA_22

      public static final boolean IS_JAVA_22
      Is true if this is Java version 22 (also 22.x versions).

      The field will return false if JAVA_VERSION is null.

      This value is initialized when the class is loaded.

      Since:
      3.15.0

    • IS_OS_AIX

      public static final boolean IS_OS_AIX
      Is true if this is AIX.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_ANDROID

      public static final boolean IS_OS_ANDROID
      Is true if this is Android.

      See https://developer.android.com/reference/java/lang/System#getProperties().

      This value is initialized when the class is loaded.

      Since:
      3.15.0

    • IS_OS_HP_UX

      public static final boolean IS_OS_HP_UX
      Is true if this is HP-UX.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_400

      public static final boolean IS_OS_400
      Is true if this is IBM OS/400.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.3

    • IS_OS_IRIX

      public static final boolean IS_OS_IRIX
      Is true if this is Irix.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_LINUX

      public static final boolean IS_OS_LINUX
      Is true if this is Linux.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_MAC

      public static final boolean IS_OS_MAC
      Is true if this is Mac.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_MAC_OSX

      public static final boolean IS_OS_MAC_OSX
      Is true if this is Mac.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_MAC_OSX_CHEETAH

      public static final boolean IS_OS_MAC_OSX_CHEETAH
      Is true if this is macOS X Cheetah.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_PUMA

      public static final boolean IS_OS_MAC_OSX_PUMA
      Is true if this is macOS X Puma.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_JAGUAR

      public static final boolean IS_OS_MAC_OSX_JAGUAR
      Is true if this is macOS X Jaguar.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_PANTHER

      public static final boolean IS_OS_MAC_OSX_PANTHER
      Is true if this is macOS X Panther.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_TIGER

      public static final boolean IS_OS_MAC_OSX_TIGER
      Is true if this is macOS X Tiger.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_LEOPARD

      public static final boolean IS_OS_MAC_OSX_LEOPARD
      Is true if this is macOS X Leopard.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_SNOW_LEOPARD

      public static final boolean IS_OS_MAC_OSX_SNOW_LEOPARD
      Is true if this is macOS X Snow Leopard.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_LION

      public static final boolean IS_OS_MAC_OSX_LION
      Is true if this is macOS X Lion.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_MOUNTAIN_LION

      public static final boolean IS_OS_MAC_OSX_MOUNTAIN_LION
      Is true if this is macOS X Mountain Lion.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_MAVERICKS

      public static final boolean IS_OS_MAC_OSX_MAVERICKS
      Is true if this is macOS X Mavericks.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_YOSEMITE

      public static final boolean IS_OS_MAC_OSX_YOSEMITE
      Is true if this is macOS X Yosemite.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_MAC_OSX_EL_CAPITAN

      public static final boolean IS_OS_MAC_OSX_EL_CAPITAN
      Is true if this is macOS X El Capitan.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.5

    • IS_OS_MAC_OSX_SIERRA

      public static final boolean IS_OS_MAC_OSX_SIERRA
      Is true if this is macOS X Sierra.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.12.0

    • IS_OS_MAC_OSX_HIGH_SIERRA

      public static final boolean IS_OS_MAC_OSX_HIGH_SIERRA
      Is true if this is macOS X High Sierra.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.12.0

    • IS_OS_MAC_OSX_MOJAVE

      public static final boolean IS_OS_MAC_OSX_MOJAVE
      Is true if this is macOS X Mojave.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.12.0

    • IS_OS_MAC_OSX_CATALINA

      public static final boolean IS_OS_MAC_OSX_CATALINA
      Is true if this is macOS X Catalina.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.12.0

    • IS_OS_MAC_OSX_BIG_SUR

      public static final boolean IS_OS_MAC_OSX_BIG_SUR
      Is true if this is macOS X Big Sur.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.12.0

    • IS_OS_MAC_OSX_MONTEREY

      public static final boolean IS_OS_MAC_OSX_MONTEREY
      Is true if this is macOS X Monterey.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_OS_MAC_OSX_VENTURA

      public static final boolean IS_OS_MAC_OSX_VENTURA
      Is true if this is macOS X Ventura.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_OS_MAC_OSX_SONOMA

      public static final boolean IS_OS_MAC_OSX_SONOMA
      Is true if this is macOS X Sonoma.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.15.0

    • IS_OS_FREE_BSD

      public static final boolean IS_OS_FREE_BSD
      Is true if this is FreeBSD.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.1

    • IS_OS_OPEN_BSD

      public static final boolean IS_OS_OPEN_BSD
      Is true if this is OpenBSD.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.1

    • IS_OS_NET_BSD

      public static final boolean IS_OS_NET_BSD
      Is true if this is NetBSD.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.1

    • IS_OS_OS2

      public static final boolean IS_OS_OS2
      Is true if this is OS/2.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_SOLARIS

      public static final boolean IS_OS_SOLARIS
      Is true if this is Solaris.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_SUN_OS

      public static final boolean IS_OS_SUN_OS
      Is true if this is SunOS.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_UNIX

      public static final boolean IS_OS_UNIX
      Is true if this is a UNIX like system, as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.1

    • IS_OS_WINDOWS

      public static final boolean IS_OS_WINDOWS
      Is true if this is Windows.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_2000

      public static final boolean IS_OS_WINDOWS_2000
      Is true if this is Windows 2000.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_2003

      public static final boolean IS_OS_WINDOWS_2003
      Is true if this is Windows 2003.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.1

    • IS_OS_WINDOWS_2008

      public static final boolean IS_OS_WINDOWS_2008
      Is true if this is Windows Server 2008.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.1

    • IS_OS_WINDOWS_2012

      public static final boolean IS_OS_WINDOWS_2012
      Is true if this is Windows Server 2012.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.4

    • IS_OS_WINDOWS_95

      public static final boolean IS_OS_WINDOWS_95
      Is true if this is Windows 95.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_98

      public static final boolean IS_OS_WINDOWS_98
      Is true if this is Windows 98.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_ME

      public static final boolean IS_OS_WINDOWS_ME
      Is true if this is Windows ME.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_NT

      public static final boolean IS_OS_WINDOWS_NT
      Is true if this is Windows NT.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_XP

      public static final boolean IS_OS_WINDOWS_XP
      Is true if this is Windows XP.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.0

    • IS_OS_WINDOWS_VISTA

      public static final boolean IS_OS_WINDOWS_VISTA
      Is true if this is Windows Vista.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      2.4

    • IS_OS_WINDOWS_7

      public static final boolean IS_OS_WINDOWS_7
      Is true if this is Windows 7.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.0

    • IS_OS_WINDOWS_8

      public static final boolean IS_OS_WINDOWS_8
      Is true if this is Windows 8.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.2

    • IS_OS_WINDOWS_10

      public static final boolean IS_OS_WINDOWS_10
      Is true if this is Windows 10.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.5

    • IS_OS_WINDOWS_11

      public static final boolean IS_OS_WINDOWS_11
      Is true if this is Windows 11.

      The field will return false if OS_NAME is null.

      OpenJDK fixed the return value for os.name on Windows 11 to versions 8, 11, and 17:

      • Affects Java versions 7u321, 8u311, 11.0.13-oracle, 17.0.1: https://bugs.openjdk.org/browse/JDK-8274737
      • Fixed in OpenJDK commit https://github.com/openjdk/jdk/commit/97ea9dd2f24f9f1fb9b9345a4202a825ee28e014

      This value is initialized when the class is loaded.

      Since:
      3.13.0

    • IS_OS_ZOS

      public static final boolean IS_OS_ZOS
      Is true if this is z/OS.

      The field will return false if OS_NAME is null.

      This value is initialized when the class is loaded.

      Since:
      3.5

    • USER_HOME_KEY

      public static final String USER_HOME_KEY
      The System property key for the user home directory.
      See Also:

    • USER_NAME_KEY

      @Deprecated public static final String USER_NAME_KEY
      Deprecated.
      Use SystemProperties.USER_NAME.
      The System property key for the user name.
      See Also:

    • USER_DIR_KEY

      @Deprecated public static final String USER_DIR_KEY
      Deprecated.
      Use SystemProperties.USER_DIR.
      The System property key for the user directory.
      See Also:

    • JAVA_IO_TMPDIR_KEY

      @Deprecated public static final String JAVA_IO_TMPDIR_KEY
      Deprecated.
      Use SystemProperties.JAVA_IO_TMPDIR.
      The System property key for the Java IO temporary directory.
      See Also:

    • JAVA_HOME_KEY

      @Deprecated public static final String JAVA_HOME_KEY
      Deprecated.
      Use SystemProperties.JAVA_HOME.
      The System property key for the Java home directory.
      See Also:

    • AWT_TOOLKIT

      public static final String AWT_TOOLKIT
      The awt.toolkit System Property.

      Holds a class name, on Windows XP this is sun.awt.windows.WToolkit.

      On platforms without a GUI, this value is null.

      Defaults to null if the runtime does not have security access to read this property or the property does not exist.

      This value is initialized when the class is loaded. If System.setProperty(String,String) or System.setProperties(java.util.Properties) is called after this class is loaded, the value will be out of sync with that System property.

      Since:
      2.1
      See Also:

  • Constructor Details

    • SystemUtils

      public SystemUtils()
      SystemUtils instances should NOT be constructed in standard programming. Instead, the class should be used as SystemUtils.FILE_SEPARATOR.

      This constructor is public to permit tools that require a JavaBean instance to operate.

  • Method Details

    • getEnvironmentVariable

      public static String getEnvironmentVariable(String name, String defaultValue)
      Gets an environment variable, defaulting to defaultValue if the variable cannot be read.

      If a SecurityException is caught, the return value is defaultValue and a message is written to System.err.

      Parameters:
      name - the environment variable name
      defaultValue - the default value
      Returns:
      the environment variable value or defaultValue if a security problem occurs
      Since:
      3.8

    • getHostName

      public static String getHostName()
      Gets the host name from an environment variable (COMPUTERNAME on Windows, HOSTNAME elsewhere).

      If you want to know what the network stack says is the host name, you should use InetAddress.getLocalHost().getHostName().

      Returns:
      the host name. Will be null if the environment variable is not defined.
      Since:
      3.6

    • getJavaHome

      public static File getJavaHome()
      Gets the current Java home directory as a File.
      Returns:
      a directory
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      2.1
      See Also:

    • getJavaIoTmpDir

      public static File getJavaIoTmpDir()
      Gets the current Java IO temporary directory as a File.
      Returns:
      a directory
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      2.1
      See Also:

    • getUserDir

      public static File getUserDir()
      Gets the current user directory as a File.
      Returns:
      a directory
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      2.1
      See Also:

    • getUserHome

      public static File getUserHome()
      Gets the current user home directory as a File.
      Returns:
      a directory
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      2.1
      See Also:

    • getUserName

      @Deprecated public static String getUserName()
      Deprecated.
      Use SystemProperties.getUserName().
      Gets the current user name.
      Returns:
      a name
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      3.10
      See Also:

    • getUserName

      @Deprecated public static String getUserName(String defaultValue)
      Deprecated.
      Use SystemProperties.getUserName(String).
      Gets the user name.
      Parameters:
      defaultValue - A default value.
      Returns:
      a name
      Throws:
      SecurityException - if a security manager exists and its checkPropertyAccess method doesn't allow access to the specified system property.
      Since:
      3.10
      See Also:

    • isJavaAwtHeadless

      public static boolean isJavaAwtHeadless()
      Returns whether the JAVA_AWT_HEADLESS value is true.
      Returns:
      true if JAVA_AWT_HEADLESS is "true", false otherwise.
      Since:
      2.1, Java 1.4
      See Also:

    • isJavaVersionAtLeast

      public static boolean isJavaVersionAtLeast(JavaVersion requiredVersion)
      Is the Java version at least the requested version.
      Parameters:
      requiredVersion - the required version, for example 1.31f
      Returns:
      true if the actual version is equal or greater than the required version

    • isJavaVersionAtMost

      public static boolean isJavaVersionAtMost(JavaVersion requiredVersion)
      Is the Java version at most the requested version.

      Example input:

      Parameters:
      requiredVersion - the required version, for example 1.31f
      Returns:
      true if the actual version is equal or less than the required version
      Since:
      3.9