System类--打印当前虚拟机的所有环境变量和变量和值

package test;

import java.util.Enumeration;
import java.util.Properties;

public class SystemInfo {
    public static void main(String[] args) {
        Properties sp = System.getProperties(); //获取当前虚拟机的环境属性
        　　 Enumeration e = sp.propertyNames();//获取环境属性中所有的变量
        　　 while(e.hasMoreElements()) {
            String key = (String)e.nextElement();
            System.out.println(key + " = " + sp.getProperty(key));
        }
    }
}

console：

java.runtime.name = Java(TM) SE Runtime Environment
sun.boot.library.path = D:\Java\jre1.8.0_144\bin
java.vm.version = 25.144-b01
java.vm.vendor = Oracle Corporation
java.vendor.url = http://java.oracle.com/
path.separator = ;
java.vm.name = Java HotSpot(TM) 64-Bit Server VM
file.encoding.pkg = sun.io
user.script =
user.country = CN
sun.java.launcher = SUN_STANDARD
sun.os.patch.level = Service Pack 1
java.vm.specification.name = Java Virtual Machine Specification
user.dir = D:\eclipse-workspace\JavaTest
java.runtime.version = 1.8.0_144-b01
java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment
java.endorsed.dirs = D:\Java\jre1.8.0_144\lib\endorsed
os.arch = amd64
java.io.tmpdir = C:\Users\sinosoft\AppData\Local\Temp\
line.separator =

java.vm.specification.vendor = Oracle Corporation
user.variant =
os.name = Windows 7
sun.jnu.encoding = GBK
java.library.path = D:\Java\jre1.8.0_144\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;D:/Java/jre1.8.0_144/bin/server;D:/Java/jre1.8.0_144/bin;D:/Java/jre1.8.0_144/lib/amd64;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;D:\Java\jdk1.8.0_144\bin;D:\Program Files\TortoiseSVN\bin;E:\eclipse-jee-oxygen-3a-win32-x86_64\eclipse;;.
java.specification.name = Java Platform API Specification
java.class.version = 52.0
sun.management.compiler = HotSpot 64-Bit Tiered Compilers
os.version = 6.1
user.home = C:\Users\sinosoft
user.timezone =
java.awt.printerjob = sun.awt.windows.WPrinterJob
file.encoding = GBK
java.specification.version = 1.8
user.name = sinosoft
java.class.path = D:\Java\jre1.8.0_144\lib\resources.jar;D:\Java\jre1.8.0_144\lib\rt.jar;D:\Java\jre1.8.0_144\lib\jsse.jar;D:\Java\jre1.8.0_144\lib\jce.jar;D:\Java\jre1.8.0_144\lib\charsets.jar;D:\Java\jre1.8.0_144\lib\jfr.jar;D:\Java\jre1.8.0_144\lib\ext\access-bridge-64.jar;D:\Java\jre1.8.0_144\lib\ext\cldrdata.jar;D:\Java\jre1.8.0_144\lib\ext\dnsns.jar;D:\Java\jre1.8.0_144\lib\ext\jaccess.jar;D:\Java\jre1.8.0_144\lib\ext\jfxrt.jar;D:\Java\jre1.8.0_144\lib\ext\localedata.jar;D:\Java\jre1.8.0_144\lib\ext\nashorn.jar;D:\Java\jre1.8.0_144\lib\ext\sunec.jar;D:\Java\jre1.8.0_144\lib\ext\sunjce_provider.jar;D:\Java\jre1.8.0_144\lib\ext\sunmscapi.jar;D:\Java\jre1.8.0_144\lib\ext\sunpkcs11.jar;D:\Java\jre1.8.0_144\lib\ext\zipfs.jar;D:\eclipse-workspace\JavaTest\bin
java.vm.specification.version = 1.8
sun.arch.data.model = 64
java.home = D:\Java\jre1.8.0_144
sun.java.command = test.SystemInfo
java.specification.vendor = Oracle Corporation
user.language = zh
awt.toolkit = sun.awt.windows.WToolkit
java.vm.info = mixed mode
java.version = 1.8.0_144
java.ext.dirs = D:\Java\jre1.8.0_144\lib\ext;C:\Windows\Sun\Java\lib\ext
sun.boot.class.path = D:\Java\jre1.8.0_144\lib\resources.jar;D:\Java\jre1.8.0_144\lib\rt.jar;D:\Java\jre1.8.0_144\lib\sunrsasign.jar;D:\Java\jre1.8.0_144\lib\jsse.jar;D:\Java\jre1.8.0_144\lib\jce.jar;D:\Java\jre1.8.0_144\lib\charsets.jar;D:\Java\jre1.8.0_144\lib\jfr.jar;D:\Java\jre1.8.0_144\classes
java.vendor = Oracle Corporation
file.separator = \
java.vendor.url.bug = http://bugreport.sun.com/bugreport/
sun.cpu.endian = little
sun.io.unicode.encoding = UnicodeLittle
sun.desktop = windows
sun.cpu.isalist = amd64