Java program for displaying file information

In this article we will learn to implement a Java program for displaying file information. A Java program is provided below which takes file name as input and displays its contents.

Java program that reads a file name from the user and then displays information about whether the file exists, whether the file is readable/writable, the type of file and the length of the file in bytes and display the content using FileInputStream.

Program is as follows:

import java.io.*;
import javax.swing.*;
class FileDemo
{
	public static void main(String args[])
	{
		String filename = JOptionPane.showInputDialog("Enter filename: ");
		File f = new File(filename);
		System.out.println("File exists: "+f.exists());
		System.out.println("File is readable: "+f.canRead());
		System.out.println("File is writable: "+f.canWrite());
		System.out.println("Is a directory: "+f.isDirectory());
		System.out.println("length of the file: "+f.length()+" bytes");
		
		try
		{
			char ch;
			StringBuffer buff = new StringBuffer("");
			FileInputStream fis = new FileInputStream(filename);
			while(fis.available()!=0)
			{
				ch = (char)fis.read();
				buff.append(ch);
			}
			System.out.println("\nContents of the file are: ");
			System.out.println(buff);
			fis.close();
		}
		catch(FileNotFoundException e)
		{
			System.out.println("Cannot find the specified file...");
		}
		catch(IOException i)
		{
			System.out.println("Cannot read file...");
		}
	}
}

Input and output for the above program is as follows:

File name: sample.txt

File exists: true
File is readable: true
File is writable: true
Is a directory: false
length of the file: 20 bytes

Contents of the file are:
Hi, welcome to Java.

Suryateja Pericherla

Suryateja Pericherla, at present is a Research Scholar (full-time Ph.D.) in the Dept. of Computer Science & Systems Engineering at Andhra University, Visakhapatnam. Previously worked as an Associate Professor in the Dept. of CSE at Vishnu Institute of Technology, India.

He has 11+ years of teaching experience and is an individual researcher whose research interests are Cloud Computing, Internet of Things, Computer Security, Network Security and Blockchain.

He is a member of professional societies like IEEE, ACM, CSI and ISCA. He published several research papers which are indexed by SCIE, WoS, Scopus, Springer and others.