Java调用存储过程出错,不知道是那里错了,帮帮忙,谢谢

Question

private CallableStatement cstmt;
public boolean addMemberBook(MemberBook memberbook) throws DBException{
DBManager manager=null;
String proc="{call bookid(?,?,?,?,?,?,?)}";
try {
   manager=new DBManager();
   boolean flage=manager.updateProc(proc);
            //这里出错,说是说是空指针异常,实在是搞不明白啊!
   cstmt.setString(1, memberbook.getMemberName());
   cstmt.setString(2, memberbook.getMemberBookID());
   cstmt.setString(3, memberbook.getMemberBookName());
   cstmt.setFloat(4, memberbook.getMemberBookPrice());
   cstmt.setInt(5, memberbook.getMemberBookNumber());
   cstmt.setString(6, memberbook.getMemberBookUnit());
   cstmt.setFloat(7, memberbook.getMemberBookMoney());
   cstmt.execute();
   if (flage==true) {
 return true;
   }
      } catch (SQLException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
            }
      return false;
}