Java現在のパスの取得

Java       
1、  System.getProperty()        ：
System.out.println(System.getProperty("user.dir"));//user.dir        

2、  File           ：
File directory = new File("");//        
try{
    System.out.println(directory.getCanonicalPath());//       
    System.out.println(directory.getAbsolutePath());//      
}catch(Exceptin e){}

File.getCanonicalPath() File.getAbsolutePath()      new File(".") new File("..")        。

#   getCanonicalPath()  ，“."         ， ”..“               
#   getAbsolutePath()  ，   ”.”、“..”，           new File()      
#   getPath()  ，       new File()      

         C:\test ：
File directory = new File("abc");
directory.getCanonicalPath(); //    C:\test\abc
directory.getAbsolutePath();    //    C:\test\abc
direcotry.getPath();                    //    abc

File directory = new File(".");
directory.getCanonicalPath(); //    C:\test
directory.getAbsolutePath();    //    C:\test\.
direcotry.getPath();                    //    .

File directory = new File("..");
directory.getCanonicalPath(); //    C:\
directory.getAbsolutePath();    //    C:\test\..
direcotry.getPath();                    //    ..




  ：System.getProperty()         ：

System.getProperty()    
# 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 ("
" on UNIX) 
# user.name                        User's account name 
# user.home                              User's home directory 
# user.dir                               User's current working directory