4+5=9

3-5=-2

7*7=49

ect

ect

ect

Just a file that someone can go in at the end of the program and just see a simple view of what he entered in order and the results. I get the file to be created but when I open it, it is blank... Here's the code:

Code:

```
import java.util.Scanner;
import java.io.*;
public class Calculator {
public int add(int num1, int num2){
int sum;
sum = num1 + num2;
return sum;
}
public int sub(int num1, int num2){
int sum;
sum = num1 - num2;
return sum;
}
public int multi(int num1, int num2){
int sum;
sum = num1 * num2;
return sum;
}
public int div(int num1, int num2){
int sum;
sum = num1 / num2;
return sum;
}
public int mod(int num1, int num2){
int sum;
sum = num1 % num2;
return sum;
}
public int pow(int base, int exp){
int sum = 1;
if (exp == 0)
{
sum = 1;
}
while (exp > 0)
{
sum = sum * base;
exp--;
}
return sum;
}
public static void main(String[] args) {
int choice;
int x;
int y;
int sum;
Calculator calc = new Calculator();
do
{
System.out.println("Calculator Program");
System.out.println("--------------------\n");
System.out.println("1. Add");
System.out.println("2. Subtract");
System.out.println("3. Multiply");
System.out.println("4. Divide");
System.out.println("5. Mod");
System.out.println("6. Power");
System.out.println("99. End Program\n");
System.out.println("Enter Choice: ");
Scanner input = new Scanner(System.in);
choice = input.nextInt();
while ((choice < 1 || choice > 6) && choice != 99)
{
System.out.println("Please enter a 1, 2, 3, 4, 5, or 6: " );
choice = input.nextInt();
}
try
{
FileWriter fstream = new FileWriter("calclog.txt");
BufferedWriter out = new BufferedWriter(fstream);
switch (choice)
{
case 1:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.add(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
case 2:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.sub(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
case 3:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.multi(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
case 4:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.div(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
case 5:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.mod(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
case 6:
System.out.println("Please enter 2 numbers only: ");
x = input.nextInt();
y = input.nextInt();
sum = calc.pow(x,y);
System.out.printf("The sum is %d\n\n",sum);
out.write(x + "+" + y + "=" + sum);
break;
}
out.close();
}
catch(Exception e)
{
System.out.println("ERROR: Could not open file!");
}
}
while (choice != 99);
System.out.println("Ending program...");
}
}
```