Some of the System Properties of Java

If we want to programmatically determine what version of the Java Runtime Environment

(JRE) is being used to execute a given application then, we can get the version via the following code illustrates:

//IN WINDOWS PLATFORM

String ver = System.getProperty("java.version"));
System.out.println("This program is running under JRE version " + ver);

if (ver.startsWith("1.5")) {
// Pseudocode.
do something appropriate for newer versions of Java ...
}

else {
// Pseudocode.
do something the pre-5.0 way ...
}

Some of the java System Properties based on JDK 1.5 are given as follows:

---

Key	Description of Associated Value

---

java.version	Java Runtime Environment version
java.vendor	Java Runtime Environment vendor
java.vendor.url	Java vendor URL
java.home	Java installation directory
java.vm.specification.version	Java Virtual Machine specification version
java.vm.specification.vendor	Java Virtual Machine specification vendor
java.vm.specification.name	Java Virtual Machine specification name
java.vm.version	Java Virtual Machine implementation version
java.vm.vendor	Java Virtual Machine implementation vendor
java.vm.name	Java Virtual Machine implementation name
java.specification.version	Java Runtime Environment specification version
java.specification.vendor	Java Runtime Environment specification vendor
java.specification.name	Java Runtime Environment specification name
java.class.version	Java class format version number
java.class.path	Java class path
java.library.path	List of paths to search when loading libraries
java.io.tmpdir	Default temporary file path
java.compiler	Name of JIT compiler to use
java.ext.dirs	Path of extension directory or directories
os.name	Operating system name
os.arch	Operating system architecture
os.version	Operating system version
file.separator	File separator (/ on Unix)
path.separator	Path separator (: on Unix)
line.separator	Line separator (\n on Unix)
user.name	User’s account name
user.home	User’s home directory
user.dir	User’s current working directory

The following table describes some of the most important system properties BASED on JDK 1.6

---

Key	Description of Associated Value

---

"file.separator"	Character that separates components of a file path. This is “/” on UNIX and “\” on Windows.
"java.class.path"	Path used to find directories and JAR archives containing class files. Elements of the class path are separated by a platform-specific character specified in the path.separator property.
"java.home"	Installation directory for Java Runtime Environment (JRE)
"java.vendor"	JRE vendor name
"java.vendor.url"	JRE vender URL
"java.version"	JRE version number
"line.separator"	Sequence used by operating system to separate lines in text files
"os.arch"	Operating system architecture
"os.name"	Operating system name
"os.version"	Operating system version
"path.separator"	Path separator character used in java.class.path
"user.dir"	User working directory
"user.home"	User home directory
"user.name"	User account name