Class SystemUtils
Helpers for java.lang.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
-
Field Summary
Modifier and TypeFieldDescriptionstatic final String
Theawt.toolkit
System Property.static final String
Thefile.encoding
System Property.static final String
Deprecated.static final boolean
Istrue
if this is Java version 1.1 (also 1.1.x versions).static final boolean
Istrue
if this is Java version 1.2 (also 1.2.x versions).static final boolean
Istrue
if this is Java version 1.3 (also 1.3.x versions).static final boolean
Istrue
if this is Java version 1.4 (also 1.4.x versions).static final boolean
Istrue
if this is Java version 1.5 (also 1.5.x versions).static final boolean
Istrue
if this is Java version 1.6 (also 1.6.x versions).static final boolean
Istrue
if this is Java version 1.7 (also 1.7.x versions).static final boolean
Istrue
if this is Java version 1.8 (also 1.8.x versions).static final boolean
Deprecated.As of release 3.5, replaced byIS_JAVA_9
static final boolean
Istrue
if this is Java version 10 (also 10.x versions).static final boolean
Istrue
if this is Java version 11 (also 11.x versions).static final boolean
Istrue
if this is Java version 12 (also 12.x versions).static final boolean
Istrue
if this is Java version 13 (also 13.x versions).static final boolean
Istrue
if this is Java version 14 (also 14.x versions).static final boolean
Istrue
if this is Java version 15 (also 15.x versions).static final boolean
Istrue
if this is Java version 9 (also 9.x versions).static final boolean
Istrue
if this is IBM OS/400.static final boolean
Istrue
if this is AIX.static final boolean
Istrue
if this is FreeBSD.static final boolean
Istrue
if this is HP-UX.static final boolean
Istrue
if this is Irix.static final boolean
Istrue
if this is Linux.static final boolean
Istrue
if this is Mac.static final boolean
Istrue
if this is Mac.static final boolean
Istrue
if this is Mac OS X Big Sur.static final boolean
Istrue
if this is Mac OS X Catalina.static final boolean
Istrue
if this is Mac OS X Cheetah.static final boolean
Istrue
if this is Mac OS X El Capitan.static final boolean
Istrue
if this is Mac OS X High Sierra.static final boolean
Istrue
if this is Mac OS X Jaguar.static final boolean
Istrue
if this is Mac OS X Leopard.static final boolean
Istrue
if this is Mac OS X Lion.static final boolean
Istrue
if this is Mac OS X Mavericks.static final boolean
Istrue
if this is Mac OS X Mojave.static final boolean
Istrue
if this is Mac OS X Mountain Lion.static final boolean
Istrue
if this is Mac OS X Panther.static final boolean
Istrue
if this is Mac OS X Puma.static final boolean
Istrue
if this is Mac OS X Sierra.static final boolean
Istrue
if this is Mac OS X Snow Leopard.static final boolean
Istrue
if this is Mac OS X Tiger.static final boolean
Istrue
if this is Mac OS X Yosemite.static final boolean
Istrue
if this is NetBSD.static final boolean
Istrue
if this is OpenBSD.static final boolean
Istrue
if this is OS/2.static final boolean
Istrue
if this is Solaris.static final boolean
Istrue
if this is SunOS.static final boolean
Istrue
if this is a UNIX like system, as in any of AIX, HP-UX, Irix, Linux, MacOSX, Solaris or SUN OS.static final boolean
Istrue
if this is Windows.static final boolean
Istrue
if this is Windows 10.static final boolean
Istrue
if this is Windows 2000.static final boolean
Istrue
if this is Windows 2003.static final boolean
Istrue
if this is Windows Server 2008.static final boolean
Istrue
if this is Windows Server 2012.static final boolean
Istrue
if this is Windows 7.static final boolean
Istrue
if this is Windows 8.static final boolean
Istrue
if this is Windows 95.static final boolean
Istrue
if this is Windows 98.static final boolean
Istrue
if this is Windows ME.static final boolean
Istrue
if this is Windows NT.static final boolean
Istrue
if this is Windows Vista.static final boolean
Istrue
if this is Windows XP.static final boolean
Istrue
if this is z/OS.static final String
Thejava.awt.fonts
System Property.static final String
Thejava.awt.graphicsenv
System Property.static final String
Thejava.awt.headless
System Property.static final String
Thejava.awt.printerjob
System Property.static final String
Thejava.class.path
System Property.static final String
Thejava.class.version
System Property.static final String
Thejava.compiler
System Property.static final String
Thejava.endorsed.dirs
System Property.static final String
Thejava.ext.dirs
System Property.static final String
Thejava.home
System Property.static final String
Thejava.io.tmpdir
System Property.static final String
Thejava.library.path
System Property.static final String
Thejava.runtime.name
System Property.static final String
Thejava.runtime.version
System Property.static final String
Thejava.specification.name
System Property.static final String
Thejava.specification.vendor
System Property.static final String
Thejava.specification.version
System Property.static final String
Thejava.util.prefs.PreferencesFactory
System Property.static final String
Thejava.vendor
System Property.static final String
Thejava.vendor.url
System Property.static final String
Thejava.version
System Property.static final String
Thejava.vm.info
System Property.static final String
Thejava.vm.name
System Property.static final String
Thejava.vm.specification.name
System Property.static final String
Thejava.vm.specification.vendor
System Property.static final String
Thejava.vm.specification.version
System Property.static final String
Thejava.vm.vendor
System Property.static final String
Thejava.vm.version
System Property.static final String
Deprecated.UseSystem.lineSeparator()
instead, since it does not require a privilege check.static final String
Theos.arch
System Property.static final String
Theos.name
System Property.static final String
Theos.version
System Property.static final String
Deprecated.UseFile.pathSeparator
, since it is guaranteed to be a string containing a single character and it does not require a privilege check.static final String
Theuser.country
oruser.region
System Property.static final String
Theuser.dir
System Property.static final String
Theuser.home
System Property.static final String
Theuser.language
System Property.static final String
Theuser.name
System Property.static final String
Theuser.timezone
System Property. -
Constructor Summary
ConstructorDescriptionSystemUtils instances should NOT be constructed in standard programming. -
Method Summary
Modifier and TypeMethodDescriptionstatic String
getEnvironmentVariable
(String name, String defaultValue) Gets an environment variable, defaulting todefaultValue
if the variable cannot be read.static String
Gets the host name from an environment variable (COMPUTERNAME on Windows, HOSTNAME elsewhere).static File
Gets the Java home directory as aFile
.static File
Gets the Java IO temporary directory as aFile
.static File
Gets the user directory as aFile
.static File
Gets the user home directory as aFile
.static String
Gets the user name.static String
getUserName
(String defaultValue) Gets the user name.static boolean
Returns whether theJAVA_AWT_HEADLESS
value istrue
.static boolean
isJavaVersionAtLeast
(JavaVersion requiredVersion) Is the Java version at least the requested version.static boolean
isJavaVersionAtMost
(JavaVersion requiredVersion) Is the Java version at most the requested version.
-
Field Details
-
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)
orSystem.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
-
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)
orSystem.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
-
FILE_SEPARATOR
Deprecated.UseFile.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)
orSystem.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
-
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)
orSystem.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_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)
orSystem.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_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)
orSystem.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
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)
orSystem.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_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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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.
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
LINE_SEPARATOR
Deprecated.UseSystem.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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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
-
PATH_SEPARATOR
Deprecated.UseFile.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)
orSystem.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
-
USER_COUNTRY
The
user.country
oruser.region
System Property. User's country code, such asGB
. First in Java version 1.2 asuser.region
. Renamed touser.country
in 1.4Defaults 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)
orSystem.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
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)
orSystem.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
-
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)
orSystem.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
-
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)
orSystem.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_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)
orSystem.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
-
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)
orSystem.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
-
IS_JAVA_1_1
public static final boolean IS_JAVA_1_1Is
true
if this is Java version 1.1 (also 1.1.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_2
public static final boolean IS_JAVA_1_2Is
true
if this is Java version 1.2 (also 1.2.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_3
public static final boolean IS_JAVA_1_3Is
true
if this is Java version 1.3 (also 1.3.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_4
public static final boolean IS_JAVA_1_4Is
true
if this is Java version 1.4 (also 1.4.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_5
public static final boolean IS_JAVA_1_5Is
true
if this is Java version 1.5 (also 1.5.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_6
public static final boolean IS_JAVA_1_6Is
true
if this is Java version 1.6 (also 1.6.x versions).The field will return
false
ifJAVA_VERSION
isnull
. -
IS_JAVA_1_7
public static final boolean IS_JAVA_1_7Is
true
if this is Java version 1.7 (also 1.7.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.0
-
IS_JAVA_1_8
public static final boolean IS_JAVA_1_8Is
true
if this is Java version 1.8 (also 1.8.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.3.2
-
IS_JAVA_1_9
Deprecated.As of release 3.5, replaced byIS_JAVA_9
Is
true
if this is Java version 1.9 (also 1.9.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.4
-
IS_JAVA_9
public static final boolean IS_JAVA_9Is
true
if this is Java version 9 (also 9.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.5
-
IS_JAVA_10
public static final boolean IS_JAVA_10Is
true
if this is Java version 10 (also 10.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.7
-
IS_JAVA_11
public static final boolean IS_JAVA_11Is
true
if this is Java version 11 (also 11.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.8
-
IS_JAVA_12
public static final boolean IS_JAVA_12Is
true
if this is Java version 12 (also 12.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.9
-
IS_JAVA_13
public static final boolean IS_JAVA_13Is
true
if this is Java version 13 (also 13.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.9
-
IS_JAVA_14
public static final boolean IS_JAVA_14Is
true
if this is Java version 14 (also 14.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.10
-
IS_JAVA_15
public static final boolean IS_JAVA_15Is
true
if this is Java version 15 (also 15.x versions).The field will return
false
ifJAVA_VERSION
isnull
.- Since:
- 3.10
-
IS_OS_AIX
public static final boolean IS_OS_AIXIs
true
if this is AIX.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_HP_UX
public static final boolean IS_OS_HP_UXIs
true
if this is HP-UX.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_400
public static final boolean IS_OS_400Is
true
if this is IBM OS/400.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.3
-
IS_OS_IRIX
public static final boolean IS_OS_IRIXIs
true
if this is Irix.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_LINUX
public static final boolean IS_OS_LINUXIs
true
if this is Linux.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_MAC
public static final boolean IS_OS_MACIs
true
if this is Mac.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_MAC_OSX
public static final boolean IS_OS_MAC_OSXIs
true
if this is Mac.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_MAC_OSX_CHEETAH
public static final boolean IS_OS_MAC_OSX_CHEETAHIs
true
if this is Mac OS X Cheetah.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_PUMA
public static final boolean IS_OS_MAC_OSX_PUMAIs
true
if this is Mac OS X Puma.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_JAGUAR
public static final boolean IS_OS_MAC_OSX_JAGUARIs
true
if this is Mac OS X Jaguar.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_PANTHER
public static final boolean IS_OS_MAC_OSX_PANTHERIs
true
if this is Mac OS X Panther.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_TIGER
public static final boolean IS_OS_MAC_OSX_TIGERIs
true
if this is Mac OS X Tiger.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_LEOPARD
public static final boolean IS_OS_MAC_OSX_LEOPARDIs
true
if this is Mac OS X Leopard.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_SNOW_LEOPARD
public static final boolean IS_OS_MAC_OSX_SNOW_LEOPARDIs
true
if this is Mac OS X Snow Leopard.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_LION
public static final boolean IS_OS_MAC_OSX_LIONIs
true
if this is Mac OS X Lion.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_MOUNTAIN_LION
public static final boolean IS_OS_MAC_OSX_MOUNTAIN_LIONIs
true
if this is Mac OS X Mountain Lion.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_MAVERICKS
public static final boolean IS_OS_MAC_OSX_MAVERICKSIs
true
if this is Mac OS X Mavericks.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_YOSEMITE
public static final boolean IS_OS_MAC_OSX_YOSEMITEIs
true
if this is Mac OS X Yosemite.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_MAC_OSX_EL_CAPITAN
public static final boolean IS_OS_MAC_OSX_EL_CAPITANIs
true
if this is Mac OS X El Capitan.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.5
-
IS_OS_MAC_OSX_SIERRA
public static final boolean IS_OS_MAC_OSX_SIERRAIs
true
if this is Mac OS X Sierra.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.12.0
-
IS_OS_MAC_OSX_HIGH_SIERRA
public static final boolean IS_OS_MAC_OSX_HIGH_SIERRAIs
true
if this is Mac OS X High Sierra.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.12.0
-
IS_OS_MAC_OSX_MOJAVE
public static final boolean IS_OS_MAC_OSX_MOJAVEIs
true
if this is Mac OS X Mojave.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.12.0
-
IS_OS_MAC_OSX_CATALINA
public static final boolean IS_OS_MAC_OSX_CATALINAIs
true
if this is Mac OS X Catalina.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.12.0
-
IS_OS_MAC_OSX_BIG_SUR
public static final boolean IS_OS_MAC_OSX_BIG_SURIs
true
if this is Mac OS X Big Sur.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.12.0
-
IS_OS_FREE_BSD
public static final boolean IS_OS_FREE_BSDIs
true
if this is FreeBSD.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.1
-
IS_OS_OPEN_BSD
public static final boolean IS_OS_OPEN_BSDIs
true
if this is OpenBSD.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.1
-
IS_OS_NET_BSD
public static final boolean IS_OS_NET_BSDIs
true
if this is NetBSD.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.1
-
IS_OS_OS2
public static final boolean IS_OS_OS2Is
true
if this is OS/2.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_SOLARIS
public static final boolean IS_OS_SOLARISIs
true
if this is Solaris.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_SUN_OS
public static final boolean IS_OS_SUN_OSIs
true
if this is SunOS.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_UNIX
public static final boolean IS_OS_UNIXIs
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
ifOS_NAME
isnull
.- Since:
- 2.1
-
IS_OS_WINDOWS
public static final boolean IS_OS_WINDOWSIs
true
if this is Windows.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_2000
public static final boolean IS_OS_WINDOWS_2000Is
true
if this is Windows 2000.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_2003
public static final boolean IS_OS_WINDOWS_2003Is
true
if this is Windows 2003.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.1
-
IS_OS_WINDOWS_2008
public static final boolean IS_OS_WINDOWS_2008Is
true
if this is Windows Server 2008.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.1
-
IS_OS_WINDOWS_2012
public static final boolean IS_OS_WINDOWS_2012Is
true
if this is Windows Server 2012.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.4
-
IS_OS_WINDOWS_95
public static final boolean IS_OS_WINDOWS_95Is
true
if this is Windows 95.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_98
public static final boolean IS_OS_WINDOWS_98Is
true
if this is Windows 98.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_ME
public static final boolean IS_OS_WINDOWS_MEIs
true
if this is Windows ME.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_NT
public static final boolean IS_OS_WINDOWS_NTIs
true
if this is Windows NT.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_XP
public static final boolean IS_OS_WINDOWS_XPIs
true
if this is Windows XP.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.0
-
IS_OS_WINDOWS_VISTA
public static final boolean IS_OS_WINDOWS_VISTAIs
true
if this is Windows Vista.The field will return
false
ifOS_NAME
isnull
.- Since:
- 2.4
-
IS_OS_WINDOWS_7
public static final boolean IS_OS_WINDOWS_7Is
true
if this is Windows 7.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.0
-
IS_OS_WINDOWS_8
public static final boolean IS_OS_WINDOWS_8Is
true
if this is Windows 8.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.2
-
IS_OS_WINDOWS_10
public static final boolean IS_OS_WINDOWS_10Is
true
if this is Windows 10.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.5
-
IS_OS_ZOS
public static final boolean IS_OS_ZOSIs
true
if this is z/OS.The field will return
false
ifOS_NAME
isnull
.- Since:
- 3.5
-
-
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
Gets an environment variable, defaulting to
defaultValue
if the variable cannot be read.If a
SecurityException
is caught, the return value isdefaultValue
and a message is written toSystem.err
.- Parameters:
name
- the environment variable namedefaultValue
- the default value- Returns:
- the environment variable value or
defaultValue
if a security problem occurs - Since:
- 3.8
-
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
Gets the Java home directory as a
File
.- Returns:
- a directory
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 2.1
- See Also:
-
getJavaIoTmpDir
Gets the Java IO temporary directory as a
File
.- Returns:
- a directory
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 2.1
- See Also:
-
getUserDir
Gets the user directory as a
File
.- Returns:
- a directory
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 2.1
- See Also:
-
getUserHome
Gets the user home directory as a
File
.- Returns:
- a directory
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 2.1
- See Also:
-
getUserName
Gets the user name.
- Returns:
- a name
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 3.10
- See Also:
-
getUserName
Gets the user name.
- Parameters:
defaultValue
- A default value.- Returns:
- a name
- Throws:
SecurityException
- if a security manager exists and itscheckPropertyAccess
method doesn't allow access to the specified system property.- Since:
- 3.10
- See Also:
-
isJavaAwtHeadless
public static boolean isJavaAwtHeadless()Returns whether theJAVA_AWT_HEADLESS
value istrue
.- Returns:
true
ifJAVA_AWT_HEADLESS
is"true"
,false
otherwise.- Since:
- 2.1, Java 1.4
- See Also:
-
isJavaVersionAtLeast
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
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
-
File.separator
, since it is guaranteed to be a string containing a single character and it does not require a privilege check.