System attributes in Windows

Getproperties
Public static properties getproperties () determines the current system property.
First, if there is a security manager, its checkpropertiesaccess method is called directly without parameters. This may cause a security exception.

Return the current system property set used by the getproperty (string) method as the properties object. If the current system property set does not exist, a system property set is created and initialized first. This system property set always contains the following key values: Key-related values
Java. Version Java Runtime Environment version
Java. Vendor Java Runtime Environment vendor
Java. Vendor. url URL of the Java vendor
Java. Home Java installation directory
Java. VM. Specification. Version Java Virtual Machine standard 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 Standard version
Java. Specification. Vendor Java Runtime Environment specification vendor
Java. Specification. Name Java Runtime Environment Standard name
Java. Class. Version Java class format version number
Java. Class. Path Java class path
List of paths searched when the java. Library. Path library is loaded
Java. Io. tmpdir default temporary file path
Name of the JIT compiler to be used by Java. Compiler
Java. Ext. dirs: path of one or more extension Directories
OS. Name of the Operating System
OS. Arch Operating System Architecture
OS. Version
File. Separator file delimiter ("/" in UNIX)
Path. Separator path separator (":" in UNIX systems)
Line. Separator line separator ("/n" in UNIX ")
User. Name: Account name of the user
User. Home user's home directory
Current working directory of user. dir

Getproperty
Public static string getproperty (string key) gets the system property of the specified key indication.
First, if there is a security manager, use this key as its parameter to call the checkpropertyaccess method. The result may cause securityexception.

If there is no set of current system properties, create and initialize the set of system properties in the same way as the getproperties method.

Parameters:
Key-name of the system property.
Return Value:
The system property string value. If there is no property with this key, null is returned.
Throw:
Securityexception-if the security manager exists and its checkpropertyaccess method does not allow access to the specified system attribute.
Nullpointerexception-if the key is null.
Illegalargumentexception-if the key is empty.