web阶段学习体验感

1) web阶段学的东西多而杂,要学会分类,思路清晰了是第一步,用的时候再去查相应的文档.2) 需要细心,有很多用的到字符串拼接的地方,一不小心就会拼错,到时候会报sql语法错误如下代码:

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@Override     public List<Route> findByPage(int cid, int start, int pageSize,String rname) { // //        String sql = "select * from tab_route where cid = ? limit ? , ?"; // //        return jtl.query(sql,new BeanPropertyRowMapper<Route>(Route.class),cid,start,pageSize);           String sql = "select * from tab_route where 1=1";         StringBuilder sb = new StringBuilder(sql);         ArrayList arr = new ArrayList<>();           if (cid != 0) {             sb.append(" and cid = ? ");             arr.add(cid);//添加？对应的值         }             if (rname != null && rname.length() > 0&& !"null".equals(rname)) {             sb.append(" and rname like ?");             arr.add("%" + rname + "%");         }         arr.add(start);         arr.add(pageSize);           sb.append(" limit ? , ? ");         sql = sb.toString();             return jtl.query(sql, new BeanPropertyRowMapper<Route>(Route.class), arr.toArray());       }