java.nio.file.Path

public interface Path
extends Comparable<Path>, Iterable<Path>, Watchable

1. A Path represents a path that is hierarchical and composed of a sequence of directory and file name elements separated by a special separator or delimiter. 
2. A root component, that identifies a file system hierarchy, may also be present.
3. The name element that is farthest from the root of the directory hierarchy is the name of a file or directory. The other name elements are directory names.
4. A Path can represent a root, a root and a sequence of names, or simply one or more name elements.
5. A Path is considered to be an empty path if it consists solely of one name element that is empty.
6. Accessing a file using an empty path is equivalent to accessing the default directory of the file system. 

method classify:
1.  Path defines the getFileName, getParent, getRoot, and subpath methods to access the path components or a subsequence of its name elements.
2.  In addition to accessing the components of a path, a Path also defines the resolve and resolveSibling methods to combine paths. 
3.  The relativize method that can be used to construct a relative path between two paths. Paths can be compared, 
    and tested against each other using the startsWith and endWith methods.
4.  This interface extends Watchable interface so that a directory located by a path can be registered with a WatchService and entries in the directory watched.

accessing files:
1. Paths may be used with the Files class to operate on files, directories, and other types of files.
For example, suppose we want a BufferedReader to read text from a file "access.log". 
The file is located in a directory "logs" relative to the current working directory and is UTF-8 encoded.

Path path = FileSystems.getDefault().getPath("logs", "access.log");
BufferReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8);

Interoperability:
1. The toPath method may be used to obtain a Path from the abstract path name represented by a java.io.File object.
　  The resulting Path can be used to operate on the same file as the java.io.File object. 
2. In addition, the toFile method is useful to construct a File from the String representation of a Path.

concurrency:
   Implementations of this interface are immutable and safe for use by multiple concurrent threads.

method:

方法签名	意义
int compareTo(Path other)	按顺序比较两个路径
boolean endsWith(Path other)	测试一个Path对象是否以给定的path为结尾
boolean endsWith(String other)	测试一个Path对象是否以给定的字符串为结尾,字符串会转换为Path对象
boolean equals(Object other)
Path getFileName()
FileSystem getFileSystem()	返回创建Path对象的文件系统对象
Path getName(int index)	以Path对象返回路径对象中一个名字组成
int getNameCount()	Returns the number of name elements in the path.
Path getParent()	Returns the parent path, or null if this path does not have a parent.
Path getRoot()	Returns the root component of this path as a Path object, or null if this path does not have a root component.
boolean isAbsolute()	Tells whether or not this path is absolute.
Iterator<Path>  iterator()	Returns an iterator over the name elements of this path.
Path normalize()	移除诸如. 和.. 等冗余的路径元素。
WatchKey  register(WatchService watcher, WatchEvent.Kind<?>... events)	Registers the file located by this path with a watch service.
WatchKey register(WatchService watcher, WatchEvent.Kind<?>[] events, WatchEvent.Modifier... modifiers)	Registers the file located by this path with a watch service.
Path relativize(Path other)	返回用this 进行解析，相对于other 的相对路径。
Path resolve(Path other)	如果other 是绝对路径，那么就返回other ；否则，返回通过连接this 和other 获得的路径。
Path resolve(String other)	如果other 是绝对路径，那么就返回other ；否则，返回通过连接this 和other 获得的路径。
Path resolveSibling(Path other)	如果other 是绝对路径，那么就返回other ；否则，返回通过连接this 的父路径和other 获得的路径。
Path resolveSibling(String other)	如果other 是绝对路径，那么就返回other ；否则，返回通过连接this 的父路径和other 获得的路径。
boolean startsWith(Path other)	类似endsWith
boolean startsWith(String other)	类似endsWith
Path subpath(int beginIndex, int endIndex)	Returns a relative Path that is a subsequence of the name elements of this path.
Path toAbsolutePath()	Returns a Path object representing the absolute path of this path.
File toFile()	Returns a File object representing this path.
Path toRealPath(LinkOption... options)	Returns the real path of an existing file.
URI toUri()	Returns a URI to represent this path.