通過（ajaxFileupload.js)提供的ajaxFileUpload方法，非同步上傳圖片，在後臺獲取並轉二進位制先存入session中，成功後返回圖片的id到ajax，並通過jQuery改變 img src的地址請求該圖片的二進位制資源。

二次上傳會覆蓋前一次儲存在session中的物件，確定儲存後會把session中的物件儲存到出資料庫中。就可以通過id來請求資料庫中的圖片二進位制資源。

• 程式碼示例spring+hibernate(前端依賴jquery.js，ajaxFileUpload.js)
• 前臺HTML程式碼
  

  <%-- 圖片展示 src為預設圖片資源--%
  <img id="upload" class="pointer img-rounded" alt="點選上傳" src="../../../resources/img/upload.jpg" width="100%">
  <%-- 圖片上傳 -->
  <input id="upfile" style="display: none" type="file" name="upfile">
   
  

  
  

• JavaScript
  
  

   /**
           * 上傳圖片
           */
           $("#upload").on('click',function(){
               $("#upfile").click();
           });
         
          $("#upfile").on("change",upfile);
  
          function upfile(){
              $.ajaxFileUpload({
                  secureuri:false,
                  url:"upImg.aj",
                  dataType:"json",
                  //fileElementId是img標籤的id
                  fileElementId:'upfile',
                  success:function(data){
                      //上傳成功後改變<img>標籤的src地址，id引數其實不需要，主要是為了重新整理img的圖片資源。
                      $("#upload").attr("src","getCurImg.aj?id="+data.message);
                      //重新繫結事件，防止二次上傳時失效
                      $("#upfile").on("change",upfile);
                  }
              });
          }
   
  

• 後臺Controller
  
  

  /**
  	 * 上傳圖片到session
  	 * @param response
  	 * @param request
       */
  	@RequestMapping(value = "/upImg.aj", method = RequestMethod.POST)
  	public void upImgSession(HttpServletResponse response, HttpServletRequest request, HttpSession httpSession) {
  
  		//獲取圖片
  		MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
  //		根據前臺name名稱得到上傳的檔案
  		MultipartFile img = multipartRequest.getFile("upfile");
  //		定義一個數組，用於儲存可上傳的檔案型別
  		List fileTypes = new ArrayList();
  		fileTypes.add("jpg");
  		fileTypes.add("jpeg");
  		fileTypes.add("bmp");
  		fileTypes.add("png");
  		String fileName = img.getOriginalFilename();
  		Long id=null;
  		ResultModel rm=null;
  		if(!(fileName==null ||"".equals(fileName))){
  			String extensionName = fileName.substring(fileName.lastIndexOf(".")+1);
  			if(fileTypes.contains(extensionName)){
  				//副檔名合法
  				try{
  					id = System.currentTimeMillis();
  					byte[] content=img.getBytes();
  					String extension="image/"+extensionName;
  					WjbDO wjbDO = new WjbDO(content,extension,id);
  					httpSession.setAttribute("curImg",wjbDO);
  				}catch (IOException e){
  					e.printStackTrace();
  				}
  				rm=new ResultModel(id.toString(), 1);
  			}
  		}else{
  			rm=new ResultModel("上傳失敗", 0);
  		}
  
  		ResponseBuilder rb = new ResponseBuilder();
  		try {
  			rb.writeJsonResponse(response,rm);
  
  		}catch (IOException e){
  			log.info("IOException",e);
  		}
  	}
  /**
  	 * 從session請求圖片二進位制流
  	 * @param response
  	 * @param request
  	 */
  	@RequestMapping(value = "/getCurImg.aj", method = RequestMethod.GET)
  	public String getCurImg(HttpServletResponse response,HttpServletRequest request,HttpSession httpSession) {
  
  
  		WjbDO wjbDO = (WjbDO)httpSession.getAttribute("curImg");
  		//設定檔案格式
  		response.setContentType(wjbDO.getExtension());
  		try{
  			OutputStream out = response.getOutputStream();
  			out.write(wjbDO.getContent());
  			out.close();
  		}catch (IOException e){
  			log.error("輸出圖片流失敗",e);
  		}
  		return null;
  
  
  	}
  /**
  	 * 確認儲存後提交圖片到資料庫
  	 * @param response
       */
  	@RequestMapping(value = "/zcdj.aj", method = RequestMethod.POST)
  	public void zcdjSave(HttpServletResponse response, HttpServletRequest request,HttpSession httpSession) {
  		//儲存上傳圖片
  		WjbDO wjbDO = (WjbDO)httpSession.getAttribute("curImg");
  		if (wjbDO!=null){
  			zcModel.setImg(wjbDO.getId());
  			wjService.saveWj(wjbDO);
  		}
  	}
   
  

• WjService.java
  

  public interface WjService {
      boolean saveWj(WjbDO wjbDO);
  
      WjbDO findById(Long id);
  
      boolean update(WjbDO wjbDO);
  
      boolean del(Long id);
  }

• WjServiceImpl.java
  

  public class WjServiceImpl implements WjService {
  
      WjbDao wjbDao;
  
      @Transactional
      public boolean saveWj(WjbDO wjbDO){
          return wjbDao.save(wjbDO);
      }
  
      public WjbDO findById(Long id){
           return wjbDao.findById(id);
      }
  
      @Transactional
      public boolean update(WjbDO wjbDO){
          wjbDao.attachDirty(wjbDO);
          return true;
      }
  
      @Transactional
      public boolean del(Long id){
          WjbDO wjbDO = wjbDao.findById(id);
          if (wjbDO!=null){
              wjbDao.delete(wjbDO);
              return true;
          }
          return false;
      }
  
      public WjbDao getWjbDao() {
          return wjbDao;
      }
  
      public void setWjbDao(WjbDao wjbDao) {
          this.wjbDao = wjbDao;
      }
  }

  
  
• WjbDao.java
  

  public class WjbDao extends HibernateDaoSupport{
      private  static  final Logger log = LoggerFactory.getLogger(WjbDao.class);
  
      protected  void initDao(){
          // do nothing
      }
  
      public boolean save(WjbDO transientInstance){
          log.debug("saving WjbDO instance");
          try{
              Serializable serializable = getHibernateTemplate().save(transientInstance);
              if (serializable != null){
                  log.debug("save successful");
                  return true;
              }
          }catch(RuntimeException re){
              log.error("save failed",re);
              throw re;
          }
          return false;
      }
      public void delete(WjbDO persistentInstance) {
          log.debug("deleting WjbDO instance");
          try {
              getHibernateTemplate().delete(persistentInstance);
              log.debug("delete successful");
          } catch (RuntimeException re) {
              log.error("delete failed", re);
              throw re;
          }
          // 重新整理Session
  //        getSession().flush();
      }
      public WjbDO findById(Long id) {
          log.debug("getting WjbDO instance with id: " + id);
          try {
              WjbDO instance = (WjbDO) getHibernateTemplate().get(
                      "nju.software.fams.data.daoobject.WjbDO", id);
              return instance;
          } catch (RuntimeException re) {
              log.error("get failed", re);
              throw re;
          }
      }
      public void attachDirty(WjbDO instance) {
          log.debug("attaching dirty WjbDO instance");
          try {
              getHibernateTemplate().saveOrUpdate(instance);
              log.debug("attach successful");
          } catch (RuntimeException re) {
              log.error("attach failed", re);
              throw re;
          }
      }
  
      public void attachClean(WjbDO instance) {
          log.debug("attaching clean WjbDO instance");
          try {
              getHibernateTemplate().lock(instance, LockMode.NONE);
              log.debug("attach successful");
          } catch (RuntimeException re) {
              log.error("attach failed", re);
              throw re;
          }
      }
  
      public void delById(long id){
          log.debug("attaching clean ZcDO instance");
          Session session = getSessionFactory().getCurrentSession();
          session.createQuery("delete from WjbDO where id=?").setParameter(0,id).executeUpdate();
      }
  }

• WjbDO.java
  
  

  @Entity
  @Table(name = "FAMS_WJB",schema = "FixAssetMS")
  public class WjbDO {
  
      private Long id;
  
      private byte[] content;
      /**
       * 副檔名
       */
      private String extension;
  
      public WjbDO(byte[] content, String extension, Long id) {
          this.content = content;
          this.extension = extension;
          this.id = id;
      }
  
      public WjbDO() {
      }
  
      @Id
      @Column(name = "ID_WJ")
      public Long getId() {
          return id;
      }
  
      public void setId(Long id) {
          this.id = id;
      }
  
      @Column(name = "CONTENT")
      public byte[] getContent() {
          return content;
      }
  
      public void setContent(byte[] content) {
          this.content = content;
      }
  
      @Column(name = "EXTENSION")
      public String getExtension() {
          return extension;
      }
  
      public void setExtension(String extension) {
          this.extension = extension;
      }
  
      @Override
      public String toString() {
          return "WjbDO{" +
                  "extension='" + extension + '\'' +
                  ", id=" + id +
                  '}';
      }
  }