FileReader/FileWriter 사용과 StringBuffer를 사용한 파일읽기/쓰기 시간단축

package ch19;

import java.io.*;

public class Ch1908
{
 public static void main(String[] args) throws IOException
 {
  FileReader  in = new FileReader(new File("D:\\study\\java\\Project\\sample\\src\\ch19\\Ch1906.java"));
  int ch;
  StringBuffer stringBuffer = new StringBuffer();
  while((ch=in.read())!=-1)
  {
   stringBuffer.append((char)ch);
  }
  System.out.println(stringBuffer);
 
  FileWriter out = new FileWriter(new File("D:\\study\\java\\Project\\sample\\src\\ch19\\Output.java"));
  out.write(stringBuffer.toString());
  out.close();
 }
}