java 將數據庫中的blob字段轉為圖片顯示在前端頁面上

1.頁面寫法

  $("#zdytp").attr("src",ApiUrl+"/abc/getpic?orgid=8020");



2.后台寫法（引入提示jar包即可）
 IOUtils 引入依賴

<dependency>
 <groupId>commons-io</groupId>
 <artifactId>commons-io</artifactId>
 <version>2.4</version>
</dependency>
 @RequestMapping(value = "/imageDisplay")
 public void imageDisplay(String orgid, HttpServletResponse response, HttpServletRequest request) throws IOException, SQLException {
 HashMap<String,Object> map = service.getById(orgid);//從數據庫查詢這條記錄信息
 if (map != null && map.size() > 0) {
 byte[] bytes = (byte[]) map.get("orglogo");//orglogo為blob大字段 存儲kb數據
 response.setContentType("image/jpeg, image/jpg, image/png, image/gif"); //設置輸出流內容格式為圖片格式
 InputStream in1 = new ByteArrayInputStream(bytes); //將字節流轉換為輸入流
 IOUtils.copy(in1, response.getOutputStream());//將字節從 InputStream復制到OutputStream中
 }
 String logoRealPathDir = request.getSession().getServletContext()
 .getRealPath("/assets/images/icons.png");//獲取默認圖片路徑
 response.setContentType("image/jpeg, image/jpg, image/png, image/gif");
 InputStream is = new FileInputStream(logoRealPathDir);

 IOUtils.copy(is, response.getOutputStream());
}


另一種寫法

@RequestMapping(value = "/showImage.do")
public void showImage(String id, HttpServletResponse response, HttpServletRequest request) throws IOException, SQLException {
 User user=userService.getUserById(Integer.valueOf(id));
 if(null != user){
 //從數據庫讀取出二進制數據……
 byte[] bb=user.getTp();
 // 將圖像輸出到Servlet輸出流中。
 ServletOutputStream sos = response.getOutputStream();
 sos.write(bb, 0, bb.length);
 sos.close();
 }
 // 禁止圖像緩存。
 response.setHeader("Pragma", "no-cache");
 response.setHeader("Cache-Control", "no-cache");
 response.setDateHeader("Expires", 0);
 response.setContentType("image/jpeg, image/jpg, image/png, image/gif");
}