io

public void getChaRu()throws Exception{
   Connection conn = this.getConnection();
   String sql = "";
   PreparedStatement ps = null;

   InputStream is = null;
   OutputStream os = null;
   try {
      //数据库的读出与写入，blob类型
      ResultSet rs = this.query("select facefile from t_wepec_user where SYSID = '894854044'");
      while (rs.next()){
         Blob blob = rs.getBlob(1);
         is = blob.getBinaryStream();
         ps.clearBatch();
         os = new FileOutputStream("D:\\img\\dd"+ new Random().nextInt(9)+".jpg");
         byte[] b = new byte[1024];
         int i = 0;
         while ((i = is.read(b))!= -1){
            os.write(b,0,i);
         }
         sql = "update t_WEPEC_USER SET FACEFILE=? WHERE sysid = '884075058'";
         ps = conn.prepareStatement(sql);
         ps.setBinaryStream(1,is,is.available());
         int a = ps.executeUpdate();
      }

         //本地写数据库，存的是blob类型
//       FileInputStream fis = new FileInputStream("D:\\img\\yy.jpg");
//       ps = conn.prepareStatement(sql);
//       sql = "update t_WEPEC_USER SET FACEFILE=? WHERE sysid = '892206194'";
//       ps.setBinaryStream(1,fis,fis.available());
//       int i = ps.executeUpdate();
//       logger.info(i);

         //本地读入，写出
//       os = new FileOutputStream("D:\\img\\gg.jpg");
//       byte[] b = new byte[1024];
//       int i =  0;
//       while ((i = is.read(b))!= -1){
//          os.write(b,0,i);
//       }
      } catch (IOException e) {
         e.printStackTrace();
      } finally {
         try {
            if(is == null){
               is.close();
            }
            if(os == null){
               os.close();
            }

         } catch (IOException e) {
            e.printStackTrace();
         }
      }
   }