java 图片处理

response.reset(); 
		response.setContentType("images/jpeg");
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);
		BufferedImage img;
		try {
			img = ImageIO.read(is);
			ImageIO.write(img, "PNG", response.getOutputStream());
			response.getOutputStream().flush();
		} catch (IOException e) {
		} 	

BufferedImage bi = ImageIO.read(item.getInputStream());【图片字节流】

System.out.println("图片大小" + bi.getHeight() + "*****" + bi.getWidth() + "**************************");