Abstract representation of the path and file name
Construction method:
public File(string pathname)
To obtain a path according to a file object
public File(string parent,string child)
Get a file object based on a sub-directory and file / directory
public File(File parent,string child)
According to a File object to get a File object parent and a child file / directory
File class member method
Creating function
public boolean createNewFile()
public boolean mkdir()
public boolean mkdirs()
Delete function
public boolean delete()
Rename (if the pathname renamed to the same, if the path name to a different cut and renamed)
public boolean renameTo(File dest)
Delete function Note:
A: If you create a file or folder path forgot to write a letter, then the default in the project path
B: java recovery does not go in the trash
C: To delete a folder, note the folder does not contain a file or folder
Judgment function
Whether public boolean isDirctory () to determine the directory
public boolean isFile () to determine whether the file
public boolean exists () determines whether there
public boolean canRead () determines whether or not readable
Whether public boolean canWrite () judgment writable
public boolean is Hidden () to determine whether to hide
The basic acquisition function
public String getAbsolutepath () Gets absolute path
public String getPath () to get the relative path
public String getName () Gets the name
public long length () to get the length, the number of bytes
pubic long lastModified () Gets the last modified time value in milliseconds
Advanced acquisition function
public String [] list () Gets an array of all files or directories developed under the folder name
public File [] listFile () Gets File develop an array of all files or directories under the folder
The date format converted to milliseconds
Date d=New Data(123456789);
SimleDateFormat sdf=new SimleDateFormat("YYYY-MM-DD HH:MM:SS");
String s=sdf.format(d);
system.out.println(s);
Implement ideas and code file name filter
public String[] list(FilenameFilter filter)
public File[] listFiles(FilenmaeFilter filter)
Recursion:
Precautions:
1. recursion must be exported otherwise infinite loop
2. recursion can not be too much, otherwise memory overflow
3. The constructor can not be called recursively