java文件操作

1、删除文件夹下的所有文件

String target_path = root_path+"/ImagesUploadTemp";
	//delete all file in target_path
	File folder = new File(target_path);
	if(folder.isDirectory()){//is directory
		File[] fileList = folder.listFiles();
		for(File file:fileList){
			if(file.isFile()){
				file.delete();
			}
		}
	}

2、复制文件

try{
		//---start copy
		File srcFile = new File(root_path+url);//source file
		File targetFile = new File(target_path+"/"+inventory_name+".xls");
		BufferedInputStream bis = new BufferedInputStream(new FileInputStream(srcFile));
		BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(targetFile));
		byte[] buffer = new byte[1024];
		int pos = bis.read(buffer);
		while(pos != -1){
			bos.write(buffer);
			pos = bis.read(buffer);
		}
		bos.close();
		bis.close();
		response.sendRedirect(cfg.getString("logolink")+"/ImagesUploadTemp/"+inventory_name+".xls");
	}catch(FileNotFoundException e){
		out.print("<b>Sorry!You want to download the file does not exist or has been deleted!</b>");
	}