Java按行读取文本文件

import java.io.*;
public class IoTest
{
public static void main(String[] args)
{
String s;
s=calculate();
System.out.println(s);
}
static String calculate()
{
StringBuffer sb=new StringBuffer("");
try{
FileReader reader = new FileReader("words.txt");
BufferedReader br = new BufferedReader(reader);
String s = null;
while((s = br.readLine()) != null) {
sb.append(s+'\n');
}
br.close();
reader.close();
}catch(Exception e){
e.printStackTrace();
}
return sb.toString();
}
}