javaweb 压缩文件图片

压缩图片分辨率 ，根据 url  和 根据 file

/**
     * <p>Title: thumbnailImage</p>
     * <p>Description: 根据图片路径生成缩略图 </p>
     * @param imagePath    原图片路径
     * @param w            缩略图宽
     * @param h            缩略图高
     * @param prevfix    生成缩略图的前缀
     * @param force        是否强制按照宽高生成缩略图(如果为false，则生成最佳比例缩略图)
     */
    public static  File thumbnailImage(File imgFile, String format,int w, int h, boolean force){
    	 File file = null; 
            try {
                // ImageIO 支持的图片类型 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif]
                // 获取图片后缀
                Image img = ImageIO.read(imgFile);
                BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
                Graphics g = bi.getGraphics();
                g.drawImage(img, 0, 0, w, h, Color.LIGHT_GRAY, null);
                g.dispose();
                ByteArrayOutputStream os = new ByteArrayOutputStream();
                ImageIO.write(bi,format,os);
                byte [] bytes = os.toByteArray();
                BufferedOutputStream bos = null;  
                FileOutputStream fos = null;  
                	file = new File("temp");  
                    fos = new FileOutputStream(file);  
                    bos = new BufferedOutputStream(fos);  
                    bos.write(bytes);  
                    bos.close();
                    fos.close();
                    os.close();
            } catch (IOException e) {
            }
            return file;
    }


    public static  InputStream thumbnailImageByUrl(String url,String format,int w, int h, boolean force){
        try {
            // ImageIO 支持的图片类型 : [BMP, bmp, jpg, JPG, wbmp, jpeg, png, PNG, JPEG, WBMP, GIF, gif]
            // 获取图片后缀
            Image img = ImageIO.read(new URL(url));
            BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
            Graphics g = bi.getGraphics();
            g.drawImage(img, 0, 0, w, h, Color.LIGHT_GRAY, null);
            g.dispose();
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            ImageIO.write(bi, format, os);
            InputStream input = new ByteArrayInputStream(os.toByteArray());
            os.close();
            return input;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }