FileInputStream和FileOutputStream实现简单的文件复制

package qiuzhao;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;public class InputOutput {    public static void main(String[] args)      {         String a="C:/Users/Administrator/Desktop/aa.txt";       String b="C:/Users/Administrator/Desktop/b.txt";       InputOutput test=new InputOutput();       test.copy(a, b);    }      public void copy(String strFrom,String strTO){        if(copyFile(strFrom,strTO)){            int b=0;              try              {                  FileInputStream in=new FileInputStream(strFrom);                FileOutputStream out=new FileOutputStream(strTO);                while((b=in.read())!=-1)                  {                      out.write(b);                  }                  in.close();//用完要关闭                  out.close();              } catch (FileNotFoundException e) {                 e.printStackTrace();              }catch(IOException e){                  e.printStackTrace();              }          }else{            System.out.print("文件不存在");        }    }    public boolean copyFile(String from,String to){        File fileFrom=new File(from);        File fileTO=new File(to);        if(!fileFrom.exists()) return false;        if(!fileTO.exists()) return false;        return true;    }}