System.getProperty()与路径Java 获得当前路径的方法1、利用System.getProperty()函数获取当前路径：1?Syste
System.getProperty()与路径
Java 获得当前路径的方法1、利用System.getProperty()函数获取当前路径：
1?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：?
1?File?directory?=?new?File("");//设定为当前文件夹
2?try{
3?????System.out.println(directory.getCanonicalPath());//获取标准的路径
4?????System.out.println(directory.getAbsolutePath());//获取绝对路径
5?}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?
