字节流复制文件

方法一：
package cn.lideng.demo2;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class Copy {
    public static void main(String[] args) throws FileNotFoundException {
        //建立两个交流对象    绑定数据源和目的地
        FileInputStream fis=null;
        FileOutputStream fos=null;
        
        fis=new FileInputStream("d:\\b.txt");
        fos=new FileOutputStream("c:\\b.txt");
        
        int len=0;
        try {
            while((len=fis.read())!=-1){
                fos.write(len);
            }
        } catch (IOException e) {
            System.out.println("文件复制失败");
        }
        finally{
            if(fos!=null){
                try {
                    fos.close();
                } catch (Exception e2) {
                    // TODO: handle exception
                }
                finally{
                    if(fis!=null){
                        try {
                            fis.close();
                        } catch (Exception e3) {
                            e3.printStackTrace();
                            System.out.println("释放资源失败");
                        }
                    }
                }
            }
        }
        
    }

}




方法二：

package cn.lideng.demo2;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class CopyArr {
    public static void main(String[] args) {
        long c = System.currentTimeMillis();
        FileInputStream fis=null;
        FileOutputStream fos=null;
        
        try {
            fis=new FileInputStream("d:\\b.txt");
            fos=new FileOutputStream("c:\\b.txt");
            byte[] b=new byte[1024];
            int len=0;
            while((len=fis.read(b))!=-1){
                fos.write(b,0,len);
            }
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            if(fos!=null){
                try {
                    fos.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }finally{
                    if(fis!=null){
                        try {
                            fis.close();
                        } catch (IOException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                            throw new RuntimeException("释放资源失败");
                        }
                    }
                }
            }
            long e=System.currentTimeMillis();
            System.out.println(e-c);
        }
    }

}