Reading File Using Java

Reading File Using Java, in this article i will step through the sample code and show you how to read the content contain inside a file.

The Sample Code.

Refer the below for the Sample Code

 

package fileHandling;

import java.io.File;

import java.util.Scanner ;

import java.io.FileNotFoundException;


public class readTheFile {

	public static void main(String[] args)throws FileNotFoundException {
		// TODO Auto-generated method stub
		
		String fileName ="c:/users/user/anotherFile.txt";
		
		File thisNewFile =new File(fileName);
		
		Scanner rfile = new Scanner(thisNewFile);
		
		while(rfile.hasNextLine()){
			
			
			String line = rfile.nextLine();
			
			System.out.println(line);
			
			
			
			
		}
		
		rfile.close();
		
		
		

	}

}

 

How it works.

1. First you will need to import the libraries ” java.io.File , java.util.Scanner,java.io.FileNotFoundException “
2. Open “c:/users/user/anotherFile.txt” and assign the file content into a String Variable called “fileName”
3. Create a new “File ” Object called” thisNewFile” and assign as an argument into the File
4. Create a new Scanner Object called”rfile” and assign the “thisNewFile” instance into the new created “rfile” scanner object
5. Use the “hasNextLine() “command to loop through the content inside the “rfile” , print out the content if detected

 

Reading File Using Exception

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;


public class App {

    public static void main(String[] args) {
     // Create a new Object " newFile " to read the File  " testFile "
        File newfile = new File("testFile.txt");
     // At the Initial Stage "lineRead " Line being read  equal null 
        BufferedReader lineRead = null;
     // try to read the file   
        try {
         // Instantiate new "fileRead" object , and pass in the" newfile" instant
            FileReader fileRead = new FileReader(newfile);
         // "lineRead " Assign the Value read through "BufferReader() " into lineRead

            lineRead = new BufferedReader(fileRead);
         // Loop through the File to check whether every single line is read
         // While line not equal to nothing ( null ) Continue reading and print out the Result
            
            String line;
            
            while( (line = lineRead.readLine()) != null ) {
                System.out.println(line);
            }
           // Catch the File Not Found Exception
            
        } catch (FileNotFoundException e) {
            System.out.println("File not found: " + newfile.toString());

          // Catch the Unable to read file Exception
        } catch (IOException e) {
            System.out.println("Unable to read file: " + newfile.toString());
        }

          // Catch the Unable to close file Exception
        finally {
            try {
                lineRead.close();
            } catch (IOException e) {
                System.out.println("Unable to close file: " + newfile.toString());
            }
            catch(NullPointerException ex) {
                // 
            }
        }
        
        

    }

}

Check out Generic Type Object in Java here