Java File Class

In this tutorial, we will learn about the File Class with the help of an example.

Java File class represents the files and directory pathnames in an abstract manner. This class is used for creation of files and directories, file searching, file deletion, etc.

Constructors of File Class

File(File parent, String child) :This constructor creates a new File instance from a parent abstract pathname and a child pathname string.
File(String pathname) :This constructor creates a new File instance by converting the given pathname string into an abstract pathname.
File(String parent, String child) :This constructor creates a new File instance from a parent pathname string and a child pathname string.
File(URI uri) :This constructor creates a new File instance by converting the given file: URI into an abstract pathname.

Methods

Methods	Description
static File createTempFile(String prefix, String suffix)	It creates an empty file in the default temporary-file directory, using the given prefix and suffix to generate its name.
boolean createNewFile()	It atomically creates a new, empty file named by this abstract pathname if and only if a file with this name does not yet exist.
boolean canWrite()	It tests whether the application can modify the file denoted by this abstract pathname.String[]
boolean canExecute()	It tests whether the application can execute the file denoted by this abstract pathname.
boolean canRead()	It tests whether the application can read the file denoted by this abstract pathname.
boolean isAbsolute()	It tests whether this abstract pathname is absolute.
boolean isDirectory()	It tests whether the file denoted by this abstract pathname is a directory.
boolean isFile()	It tests whether the file denoted by this abstract pathname is a normal file.
String getName()	It returns the name of the file or directory denoted by this abstract pathname.
String getParent()	It returns the pathname string of this abstract pathname's parent, or null if this pathname does not name a parent directory.
Path toPath()	It returns a java.nio.file.Path object constructed from the this abstract path.
URI toURI()	It constructs a file: URI that represents this abstract pathname.
File[] listFiles()	It returns an array of abstract pathnames denoting the files in the directory denoted by this abstract pathname
long getFreeSpace()	It returns the number of unallocated bytes in the partition named by this abstract path name.
String[] list(FilenameFilter filter)	It returns an array of strings naming the files and directories in the directory denoted by this abstract pathname that satisfy the specified filter.
boolean mkdir()	It creates the directory named by this abstract pathname.

Example 1


import java.io.*;  
public class FileDemo 
{  
    public static void main(String[] args) 
    {  
  
        try {  
            	File file = new File("javaFile123.txt");  
            	if (file.createNewFile()) 
		{  
                	System.out.println("New File is created!");  
            	} 
		else 
		{  
                System.out.println("File already exists.");  
            	}  
        } 
	catch (IOException e) 
	{  
            e.printStackTrace();  
        }  
  
    }  
}  

Output:
New File is created!

Example 2


import java.io.*;  
public class FileDemo2 {  
    public static void main(String[] args) {  
  
        String path = "";  
        boolean bool = false;  
        try {  
            // createing  new files  
            File file  = new File("testFile1.txt");  
            file.createNewFile();  
            System.out.println(file);  
            // createing new canonical from file object  
            File file2 = file.getCanonicalFile();  
            // returns true if the file exists  
            System.out.println(file2);  
            bool = file2.exists();  
            // returns absolute pathname  
            path = file2.getAbsolutePath();  
            System.out.println(bool);  
            // if file exists  
            if (bool) {  
                // prints  
                System.out.print(path + " Exists? " + bool);  
            }  
        } catch (Exception e) {  
            // if any error occurs  
            e.printStackTrace();  
        }  
    }  
}  
Output:

testFile1.txt
/home/Work/Project/File/testFile1.txt
true
/home/Work/Project/File/testFile1.txt Exists? true

Example 3


import java.io.*;  
public class FileExample 
{  
	public static void main(String[] args) 
	{  
    		File f=new File("/Users/sonoojaiswal/Documents");  
    		String filenames[]=f.list();  
    		for(String filename:filenames)
		{  
        		System.out.println(filename);  
    		}  
	}  
}  

Output:

"info.properties"
"info.properties".rtf
.DS_Store
.localized
Alok news
apache-tomcat-9.0.0.M19
apache-tomcat-9.0.0.M19.tar
bestreturn_org.rtf
BIODATA.pages
BIODATA.pdf
BIODATA.png
struts2jars.zip
workspace