JAVA EE: Java Tutorial : Java Exception handling (finally block-BufferedReader)

Thursday 23 June 2016

Java Tutorial : Java Exception handling (finally block-BufferedReader)

Click here to watch in Youtube :
https://www.youtube.com/watch?v=C9zD5yTG2sU&list=UUhwKlOVR041tngjerWxVccw

FinallyDemo.java

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.Scanner;

public class FinallyDemo
{
    public static void main(String[] args)
    {

        BufferedReader bufferedReader = null;

        try
        {

            Scanner scanner = new Scanner(System.in);
            System.out.print("Enter the fileName : ");
            String fileName = scanner.nextLine();
            scanner.close();

            /*
             * Wrap a BufferedReader around FileReader.
             */
            bufferedReader = new BufferedReader(new FileReader(
                    fileName));

            /*
             * Use the readLine method of the BufferedReader
             * to read one line at a time. the readLine
             * method returns null when there is nothing
             * else to read.
             */
            String line = null;

            while ((line = bufferedReader.readLine()) != null)
            {
                System.out.println(line);
            }

        }
        catch (FileNotFoundException fileNotFoundException)
        {
            fileNotFoundException.printStackTrace();
        }
        catch (IOException ioException)
        {
            ioException.printStackTrace();
        }
        finally
        {

            System.out.print("Inside finally block....");
            if (bufferedReader != null)
            {
                // Close the BufferedReader when we're done.
                try
                {
                    System.out
                            .println(",close the BufferedReader....");
                    bufferedReader.close();
                }
                catch (IOException ioException)
                {
                    ioException.printStackTrace();
                }
            }
        }

    }
}

Output

Enter the fileName : myfile.txt
Peter
David
Julia
Inside finally block....,close the BufferedReader....

-----------------------------------------------

Enter the fileName : hi.txt
java.io.FileNotFoundException: hi.txt (The system cannot find the file specified)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(FileInputStream.java:195)
    at java.io.FileInputStream.<init>(FileInputStream.java:138)
    at java.io.FileInputStream.<init>(FileInputStream.java:93)
    at java.io.FileReader.<init>(FileReader.java:58)
    at FinallyDemo.main(FinallyDemo.java:26)
Inside finally block....