一般情況下圖片的儲存在hdfs上，資料庫只儲存圖片的路徑，特殊情況採用這個方案。
資料庫方面：

實體方面採用byte陣列進行存取：

 private byte[] img;

我在本地磁碟放了一張圖片，現在進行讀取：

public String save(){
//建立實體
DashboardBoard board = new DashboardBoard();
byte[] inputStream2ByteArray;
             try {
             inputStream2ByteArray = InputStream2ByteArray("D:\\ceshi.png"
 
);
             } catch (IOException e) {
             e.printStackTrace();
             }
            board.setImg(exportBoard);
            //呼叫儲存方法
            boardDao.save(board);
            //具體業務~略
        }
        //主要的工具方法
    public byte[] InputStream2ByteArray(String filePath) throws IOException {

        InputStream in
 
 = new FileInputStream(filePath);
        byte[] data = toByteArray(in);
        in.close();

        return data;
    }

    public byte[] toByteArray(InputStream in) throws IOException {

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024 * 4];
        int
 
 n = 0;
        while ((n = in.read(buffer)) != -1) {
            out.write(buffer, 0, n);
        }
        return out.toByteArray();
    }

通過以上方式可以把圖片以二進位制的方式儲存到資料庫中，親測，有效。

圖片的顯示：

前臺頁面使用img標籤進行圖片的顯示

<img src="localhost:8080/xxx/getBoardDataImg.do?id=xx&width=150&height=150" />

後臺程式碼：

@RequestMapping(value = "/getBoardDataImg")
    @ResponseBody
    public String ceshi(@RequestParam(name = "id") Long id ,@RequestParam(name = "width") int width,@RequestParam(name = "height") int height,  HttpServletResponse response,HttpServletRequest request) throws IOException{
        DashboardBoard board = boardDao.getBoard(id);
        byte[] data = board.getImg();
        //獲取縮圖
        data = boardService.scaleImage(data, width, height);  
        response.setContentType("image/jpeg");  
        response.setCharacterEncoding("UTF-8");  
        OutputStream outputSream = response.getOutputStream();  
        InputStream in = new ByteArrayInputStream(data);  
        int len = 0;  
        byte[] buf = new byte[1024];  
        while ((len = in.read(buf, 0, 1024)) != -1) {  
            outputSream.write(buf, 0, len);  
        }  
        outputSream.close();  
        return null;
    }

}
/**
     * 獲取縮圖
     * @throws IOException
     */
    public  byte[] scaleImage(byte[] data, int width, int height) throws IOException {
        BufferedImage buffered_oldImage = ImageIO.read(new ByteArrayInputStream(data));
        int imageOldWidth = buffered_oldImage.getWidth();
        int imageOldHeight = buffered_oldImage.getHeight();
        double scale_x = (double) width / imageOldWidth;
        double scale_y = (double) height / imageOldHeight;
        double scale_xy = Math.min(scale_x, scale_y);
        int imageNewWidth = (int) (imageOldWidth * scale_xy);
        int imageNewHeight = (int) (imageOldHeight * scale_xy);
        BufferedImage buffered_newImage = new BufferedImage(imageNewWidth, imageNewHeight, BufferedImage.TYPE_INT_RGB);
        buffered_newImage.getGraphics().drawImage(
                buffered_oldImage.getScaledInstance(imageNewWidth, imageNewHeight, BufferedImage.SCALE_SMOOTH), 0, 0,
                null);
        buffered_newImage.getGraphics().dispose();
        ByteArrayOutputStream outPutStream = new ByteArrayOutputStream();
        ImageIO.write(buffered_newImage, "jpeg", outPutStream);
        return outPutStream.toByteArray();
    }

}

使用流展示圖片到前端，通過設定width和height進行縮圖的處理