How to save a value in a .txt n retrive back the exact value from the file?

Question

Well I have a number. Let's say 600. I need to save this value in a .txt file so that I can retrive this value. I tried using the below source code. It can be executed but I'll get num 49 everytime I execute it even though the value in my .txt is 600.
try {
               File inputFile = new File("Lt.txt");
               File outputFile = new File("outagain.txt");
FileReader in = new FileReader("Lt.txt");
FileWriter out = new FileWriter(outputFile);
int c;
          c = in.read();
          in.close();
System.out.print("\nggggggggg"+c);
in.close();
               } catch (IOException ex) {
               System.out.println("IOException:"+ex.toString());

Answer 1

Thank you. I execute the program below. I can now retrive the data from the Lt.txt. But the value is limited to 3 digits. For example, the content of my file is 777888.
When I run the program, I only get 777. How can I retrive the whole exact number?               
import java.io.*;
               class Test {     
               public static void main(String args[]) {          
               try {               
               File inputFile = new File("Lt.txt");               
               File outputFile = new File("outagain.txt");                    
               FileReader in = new FileReader("Lt.txt");               
               FileWriter out = new FileWriter(outputFile);               
               char[] tmp = new char[3];               
               int cnt = in.read(tmp);                              
               System.out.print("\nRead: ");               
               for (int i = 0; i < cnt; i++) {                    
               System.out.print(tmp);               }               
               System.out.println(" ");               
               in.close();          }
               catch (IOException ex) {               
               System.out.println("IOException:"+ex.toString());          }     }}