java的IO流的一些测试

public class Demo02 {
        public static void main(String[] args) {
            //获取当前毫秒值，用于测试
            long l = System.currentTimeMillis(); 
            //创建文件对象,需要读取的文件
            File file = new File("F:/java/sql语句的执行顺序.txt");
            //写入的文件
            File file2 = new File("F:/test2.txt");
            //创建字节输入流和输出流
            BufferedInputStream in=null;
            BufferedOutputStream out=null;
            //创建一个存储数据的字节数组
            byte [] b=new byte [3];
            try {
             in =new BufferedInputStream(  new FileInputStream(file));
             out = new BufferedOutputStream(new FileOutputStream(file2));
             int read=0;
             //如果没有数据了会返回-1；如果还有会返回数据的长度
                    while ((read = in.read(b))!=-1) {
                        //读取多少输出多少
                        out.write(b,0,read);
                    }
                    //刷新
                    out.flush();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                //关流
                if(out!=null){
                    try {
                    
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                if(in!=null){
                    try {
                        
                        in.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            long m = System.currentTimeMillis();
            System.out.println(m-l);
        }    
    
        //-------------------------------------------------------------------------------------------------------------
        public static void demo02(){
            
            long l = System.currentTimeMillis(); 
            //创建文件对象,需要读取的文件
            File file = new File("F:/java/sql语句的执行顺序.txt");
            //写入的文件
            File file2 = new File("F:/test2.txt");
            //创建字节输入流和输出流
            FileOutputStream out=null;
            FileInputStream in=null;
            //创建一个存储数据的字节数组
            byte [] b=new byte [3];
            try {
             in = new FileInputStream(file);
             out = new FileOutputStream(file2);
             int read=0;
             //如果没有数据了会返回-1；如果还有会返回数据的长度
                    while ((read = in.read(b))!=-1) {
                        //读取多少输出多少
                        out.write(b,0,read);
                    }
                    //刷新
                    out.flush();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally {
                //关流
                if(out!=null){
                    try {
                    
                        out.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
                if(in!=null){
                    try {
                        
                        in.close();
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                }
            }
            long m = System.currentTimeMillis();
            System.out.println(m-l);            
        }    
}