java 路径的相关
1、利用System.getProperty()函数获取当前路径：
System.out.println(System.getProperty("user.dir"));//user.dir指定了当前的路径
2、使用File提供的函数获取当前路径：
File directory = new File("");//设定为当前文件夹
try{
??? System.out.println(directory.getCanonicalPath());//获取标准的路径
??? System.out.println(directory.getAbsolutePath());//获取绝对路径
}catch(Exceptin e){}
File.getCanonicalPath()和File.getAbsolutePath()大约只是对于new File(".")和new File("..")两种路径有所区别。
# 对于getCanonicalPath()函数，“."就表示当前的文件夹，而”..“则表示当前文件夹的上一级文件夹
# 对于getAbsolutePath()函数，则不管”.”、“..”，返回当前的路径加上你在new File()时设定的路径
# 至于getPath()函数，得到的只是你在new File()时设定的路径
比如当前的路径为 C:\test ：
File directory = new File("abc");
directory.getCanonicalPath(); //得到的是C:\test\abc
directory.getAbsolutePath();??? //得到的是C:\test\abc
direcotry.getPath();??????????????????? //得到的是abc
File directory = new File(".");
directory.getCanonicalPath(); //得到的是C:\test
directory.getAbsolutePath();??? //得到的是C:\test\.
direcotry.getPath();??????????????????? //得到的是.
File directory = new File("..");
directory.getCanonicalPath(); //得到的是C:\
directory.getAbsolutePath();??? //得到的是C:\test\..
direcotry.getPath();??????????????????? //得到的是..
?
另外：System.getProperty()中的字符串参数如下：
System.getProperty()参数大全
# 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 temp 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
