返回檔案流，給img的src 賦值 為請求地址

– 前端為dojo，後端為java -hibernate - spring

1. dao

@Override
	public byte[] queryPhotoImg(String Id) {
        StringBuffer sql = new StringBuffer();
        sql.append(" SELECT  PHOTO");
        sql.append(" FROM TAB_TEST  ");
        sql.append(" WHERE ID= ?   ");
        Session session = (Session) getCurrentSession();
        SQLQuery query = session.createSQLQuery(sql.toString());
        query.addScalar("PHOTO",Hibernate.BLOB);
        query.setParameter(0,sAreaId);
        Blob blob  = (Blob) query.uniqueResult();
        if(blob == null){
        	return null;
		}
        InputStream is = null;
        byte[] b = null;
        try {
              is = blob.getBinaryStream();
              b = new byte [( int ) blob.length ()];
              is.read ( b );

        } catch (IOException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try
            {
                is.close ();
                is = null;
            }
            catch ( IOException e )
            {
                e.printStackTrace ();
            }
        }
        return b;
	}
 

2. Service

public byte[] queryPhotoImg(String  Id) {
   	if(StringUtils.isNotEmpty(Id)) {
   		return  Dao.queryPhotoImg(sAreaId);
   	}
   	return null;
   }

3. Rset

@RequestMapping(value ="/queryImg")
   public void queryPhotoImg(HttpServletRequest req, HttpServletResponse res,String id) throws IOException {
       byte[] bytes = Service.queryPhotoImg(id);
       if(bytes == null){
       	 res.getWriter().print("null");
   	}else {
           res.setContentType("image/jpg");
           res.setContentLength(bytes.length);
           res.getOutputStream().write(bytes);
       }
   }
 

前端

initImg:function(){
        this. Photo.onerror = dojo.hitch(this,function(dom){
            dom.src = "../images/none.png";
        }, this.showDoorPhoto);  //返回錯誤時，預設圖片
        this.showDoorPhoto.src = "[src]?id=?"+ Id+"&t=" + Math.random();  //每次都重新請求url
    },