读取oracle中blog字段

 Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
 String URL=dbmes.url;
 Connection con = DriverManager.getConnection(URL,dbmes.usrname,dbmes.pwd);
try{
// 准备语句执行对象
 String bh=request.getParameter("dwmc");
 Statement stmt = con.createStatement();
 String sql = "select tp1 from HJ_ZDQY_TAB where dwmc='"+bh+"'";
 
 ResultSet rs = stmt.executeQuery(sql);
 if (rs.next()) {
  Blob tp1 = rs.getBlob("tp1");
  long size1 = tp1.length();
  if(size1<=0){
   rs.close();
   response.sendRedirect("../images/error.jpg");
  }else{
   byte[] bs1 = tp1.getBytes(1, (int)size1);
   response.setContentType("image/jpeg");
   response.getOutputStream().write(bs1);
   rs.close();
  }
 }else {
  rs.close();
  response.sendRedirect("../images/error.gif");
 }
}
finally{
  
 con.close();
}
     out.clear();
  out=pageContext.pushBody();