2단계 자원반납 팩토링

package springbook.learningtest.template;

import java.io.BufferedReader;

import java.io.FileReader;

import java.io.IOException;

public class Calculator {

public Integer calcSum(String filepath) {

BufferedReader br = null;

int sum = 0;

try {

br = new BufferedReader(new FileReader(filepath));

String line = null;

while( (line=br.readLine())!=null ){

sum += Integer.parseInt(line);

}

br.close();

} catch (IOException ie) {

// TODO: handle exception

ie.printStackTrace();

} catch (Exception e){

e.printStackTrace();

} finally {

if(br!=null){

try {

br.close();

} catch (Exception e2) {

// TODO: 무시

}

}

}

return sum;

}

}