图片文件上次获取图片文件实际类型

packagecom.ylw.p2p.common.utils; importjava.awt.image.BufferedImage; importjava.io.BufferedInputStream; importjava.io.BufferedOutputStream; importjava.io.File; importjava.io.FileInputStream; importjava.io.FileNotFoundException; importjava.io.FileOutputStream; importjava.io.IOExcep