Reprint: Java File object manipulation

Java file Object manipulation
When we do a file operation, we need to know some information about the file. The file class provides some member functions to manipulate files and obtain information about some files.
1. Create a new File object
You can use the following three methods to create a new file object:
File MyFile; MyFile = new File ("ETC/MOTD");
Or
MyFile = new File ("/etc", "MOTD"); More useful if the directory or filename are variables
Or
File Mydir = new file ("/etc"); MyFile = new File (Mydir, "MOTD");
These three methods depend on how you access the file.
For example, if you use only one file in an application, the first way to create a file structure is easiest.
But if you open several files in the same directory, the second or third structure is better.
2, file testing and use
Once you create a file object, you can use the following member functions to obtain file-related information:
File name: String getName ()
Path: String GetPath ()
String Getabslutepath ()
String GetParent ()
Boolean Renameto (File newName)
File Tests: Boolean exists (), Boolean CanWrite (), Boolean CanRead (), Boolean Isfile (), Boolean isdirectory (), Boolean I Sabsolute ()
General file Information L long lastmodified () L long Length ()
Directory Usage L boolean mkdir () L string[] list ()
3. File Information Acquisition Example program
Here is a standalone program that displays basic information about the file, which is transmitted via command-line arguments:
Import java.io.*; Class fileinfo{
File Filetocheck;
public static void Main (String args[]) throws ioexception{