File Parse code gives me exceptions instead of a number and file writing code gives writes gibberish instead of a number

This code reads a notepad file this notepad file has the number 10 on it it returns a gibberish letter for some reason instead of 10 I think it is the ascii code but i do not know Also this code is modified from my programming teachers code so I do not take credit for it 

/**
     *Goes in to the file and extracts a number.
     * @param fileName
     * @return an integer
     */
    static int getNumberFromFile(String fileName){
        int j = 599;
        try {
            File textFile = new File(fileName);
            Scanner sc = new Scanner(textFile);
            String input = sc.nextLine();
            j = Integer.parseInt(input);

        } catch (Exception e) {
            System.out.println("Exception: " + e);
        }
        return j;

    }

throws this wierd exception Exception: java.lang.NumberFormatException: For input string: "10" and this code

/**
 * writes data for the ai to adapt its strategy
 *@param number is the number to write
 * @param fileName is the fileName
 */
public static void writeToFile(String fileName,int number) {

    BufferedWriter output = null;
    try {
        File aFile = new File(fileName);
        FileWriter myWriter = new FileWriter(aFile);
        output = new BufferedWriter(myWriter);
        output.write(number);
        output.newLine();
        output.close();
    } catch (Exception e) {
        System.out.println("Exception:" + e);
        System.out.println("please Report this bug it doesnt understand");
        System.exit(1);
    }
}

dont worry about some of the exception catch things those were for me to see if the exceptions are caught it just prints a (nonsense) message. and some of the stuff where a talk about an ai dont worry just need this code working I can post why the ai needs it but i dont think it is relevant

Jon Skeet
people
quotationmark

This line doesn't do what you expect:

output.write(number);

It's calling write on a BufferedWriter, so you should consult the documentation... at which point you find you're calling this method.

public void write(int c)
      throws IOException

Writes a single character.

Overrides:
write in class Writer Parameters:
c - int specifying a character to be written

And following the write link gives more details:

Writes a single character. The character to be written is contained in the 16 low-order bits of the given integer value; the 16 high-order bits are ignored. Subclasses that intend to support efficient single-character output should override this method.

So, you're writing the Unicode character U+000A - or would be if the value were really 10. I strongly suspect it's not though, as that would just be a line feed character.

If you're trying to write the decimal representation of the number though, you should turn it into a string first:

output.write(String.valueOf(number));

people

See more on this question at Stackoverflow