Can't read data from a file in java

Question

Here is the problem I want to solve https://www.codeeval.com/open_challenges/100/

and here is my solution:

public static void main(String[] args) {
    // TODO code application
    File file = null;
    try{
    FileReader f = new FileReader("C:\\Users\\ranaa\\Desktop\\merna1.txt");
    BufferedReader br = new BufferedReader(f);
    String getContent;
    while((getContent=br.readLine())!=null){
        int content = Integer.parseInt(getContent);
        System.out.println(content);
        if(content %2==0)
            System.out.println("1");
        else
            System.out.println("0");
    }
    }catch(Exception e){
        System.out.println(e);
    }
}

no output appears to me nor exception.

Can anybody help me?

maybe your code is waiting for the String path = scan.nextLine(); — Leo, Aug 03 '14 at 20:12
This post is for a challenge. I just wanted to clarify if anybody else was working on the challenge. — Brett Holmes, Aug 03 '14 at 20:16
@Leo it contains numbers like 1245 and the next line 3424 and so on — memo amam, Aug 03 '14 at 20:17
@PhotographyBum how many points people that are getting the answers from SO are earning in this challenge? :-) — Leo, Aug 03 '14 at 20:28
Using a debugger, what is `br.readLine()` the first time the `while` loop is reached? — Mike Koch, Aug 03 '14 at 20:30
@PhotographyBum i just need to know my mistake as i am beginner in programming .. thats all — memo amam, Aug 03 '14 at 20:30
@MikeK only the first number and then "java.lang.NumberFormatException: For input string: " — memo amam, Aug 03 '14 at 20:36
@Leo I don't know the points, but it wouldn't be hard if somewhat answered it with a fully done perfect coding ;) Memo I understand I just wanted the community to understand. — Brett Holmes, Aug 03 '14 at 20:39
Then you may want to update your question with that information, especially the `NumberFormatException`, since "no output appears to me nor exception" is no longer true. — Mike Koch, Aug 03 '14 at 20:46

score 1 · Answer 1 · edited May 23 '17 at 12:11

Before seeing my code

First, it is good to put whatever is closeable in try catch block with resources so there is no need to be worried about closing it at end because closing connection is done implicitly. read this: http://docs.oracle.com/javase/tutorial/essential/exceptions/tryResourceClose.html

Second, How to use BuffeRreader just take a look at this

How to use Buffered Reader in Java

Third, How to use Scanner just take a look at this

How can I read input from the console using the Scanner class in Java?

Code:

    String filePath = "C:\\Users\\KICK\\Desktop\\number.txt";
    File file = new File(filePath);
    try (BufferedReader reader = new BufferedReader(new FileReader(filePath))) {
        String line;
        while ((line = reader.readLine()) != null) {
           int current = Integer.parseInt(line);

            if( current % 2 == 0)
                System.out.println("1");
            else
                System.out.println("0");
        }
    } catch (Exceptio e) {
        System.out.println(e);
    }

or you can use Scanner class

Code:

String filePath = "C:\\Users\\KICK\\Desktop\\number.txt";
        File file = new File(filePath);
        try(Scanner input = new Scanner(file)){
           while(input.hasNext()){
                int current = Integer.parseInt(input.next());

                if( current % 2 == 0)
                    System.out.println("1");
                else
                    System.out.println("0");
                     }
       }catch(Exception e){
           System.out.println(e);
       }

output:

0
0
1

number.txt content :

701
4123
2936

Can't read data from a file in java

1 Answers1