BufferedImage缩小图片大小

通过图片的IO流穿入, 即可输出一张同样高和宽, 大小小很多的图片!!

/**
	 * 穿入Inputstream图片IO流即可
	 * 
	 * @param stream
	 */
public void SavePngImage(InputStream stream) {
        int w = 0;
        int h = 0;
        BufferedImage bufImg = null;
        try {
        	BufferedImage image = ImageIO.read(stream);
        	w = image.getWidth();
        	h = image.getHeight();
	        bufImg = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
	        //bufImg = ImageUtil.createCompatibleImage(w, h, Transparency.OPAQUE);
	        Graphics2D g2d = bufImg.createGraphics();
	        //File file = new File("e:\\2.gif");
	        //javax.imageio.ImageIO.read(file);
        
			g2d.drawImage(image, 0, 0, null);
			g2d.dispose();
		} catch (IOException e) {
			e.printStackTrace();
		}
        
        
        //输出的图片路径
        saveImage(bufImg, "c:/test.jpg");
    }
	// 保存图片
    public void saveImage(BufferedImage img, String path) {
        try {
            String extension = path.substring(path.lastIndexOf('.') + 1);
            extension = isFormatSupported(extension) ? extension : "png";
            ImageIO.write(img, extension, new File(path));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    // 判断ImageIO是否支持指定的图片格式
    public static boolean isFormatSupported(String format) {
        for (String f : ImageIO.getWriterFormatNames()) {
            if (f.equalsIgnoreCase(format)) { return true; }
        }

        return false;
    }
    public static void main(String[] args){
        File file = new File("c:/input.jpg");
        xxx.SavePngImage(file.getInputStream());
    }