Java-System Properties, getProperty, setProperty

http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html

tutorial/essential/environment/sysprop.html

http://www.leepoint.net/notes-java/io/30properties_and_preferences/40sysprops/10sysprop.html

http://blog.csdn.net/szwangdf/article/details/4366581

System Properties(系统属性)：

The following table describes some of the most important system properties

Key	Meaning
"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 vendor 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

Properties props=System.getProperties(); //系统属性
System.out.println("Java的运行环境版本："+props.getProperty("java.version"));
System.out.println("Java的运行环境供应商："+props.getProperty("java.vendor"));
System.out.println("Java供应商的URL："+props.getProperty("java.vendor.url"));
System.out.println("Java的安装路径："+props.getProperty("java.home"));
System.out.println("Java的虚拟机规范版本："+props.getProperty("java.vm.specification.version"));
System.out.println("Java的虚拟机规范供应商："+props.getProperty("java.vm.specification.vendor"));
System.out.println("Java的虚拟机规范名称："+props.getProperty("java.vm.specification.name"));
System.out.println("Java的虚拟机实现版本："+props.getProperty("java.vm.version"));
System.out.println("Java的虚拟机实现供应商："+props.getProperty("java.vm.vendor"));
System.out.println("Java的虚拟机实现名称："+props.getProperty("java.vm.name"));
System.out.println("Java运行时环境规范版本："+props.getProperty("java.specification.version"));
System.out.println("Java运行时环境规范供应商："+props.getProperty("java.specification.vender"));
System.out.println("Java运行时环境规范名称："+props.getProperty("java.specification.name"));
System.out.println("Java的类格式版本号："+props.getProperty("java.class.version"));
System.out.println("Java的类路径："+props.getProperty("java.class.path"));
System.out.println("加载库时搜索的路径列表："+props.getProperty("java.library.path"));
System.out.println("默认的临时文件路径："+props.getProperty("java.io.tmpdir"));
System.out.println("一个或多个扩展目录的路径："+props.getProperty("java.ext.dirs"));
System.out.println("操作系统的名称："+props.getProperty("os.name"));
System.out.println("操作系统的构架："+props.getProperty("os.arch"));
System.out.println("操作系统的版本："+props.getProperty("os.version"));
System.out.println("文件分隔符："+props.getProperty("file.separator")); //在 unix 系统中是＂／＂
System.out.println("路径分隔符："+props.getProperty("path.separator")); //在 unix 系统中是＂:＂
System.out.println("行分隔符："+props.getProperty("line.separator")); //在 unix 系统中是＂/n＂
System.out.println("用户的账户名称："+props.getProperty("user.name"));
System.out.println("用户的主目录："+props.getProperty("user.home"));
System.out.println("用户的当前工作目录："+props.getProperty("user.dir"));