public?static?void?CopyFile(File?file1,File?file2)throws?IOException{
		if(!file1.exists()){
		throw?new?IllegalArgumentException("文件"+file1+"不存在");	
		}
		
		if(!file1.isFile()){
		throw?new?IllegalArgumentException(file1+"不是文件");		
		}
		
		FileInputStream?in?=?new?FileInputStream(file1);
		FileOutputStream?out?=?new?FileOutputStream(file2);
		byte[]buf?=?new?byte[8*1024];
		int?b;
		while((b?=?in.read(buf,?0?,?buf.length))!=-1){
		out.write(buf,?0,?b);
		out.flush();
		}
		in.close();
		out.close();
	}

package?javaIO;

import?java.io.File;
import?java.io.IOException;

public?class?IOUtiltest3?{

	public?static?void?main(String[]?args)?{
		try?{
			IOutil.CopyFile(new?File("f\\123.txt"),?new?File("f\\456.txt"));
		}?catch?(IOException?e)?{
			//?TODO?Auto-generated?catch?block
			e.printStackTrace();
		}

	}

}